SBO project IWT Tweede jaarlijks rapport

Faculteit Toegepaste Wetenschappen Departement Burgerlijke Bouwkunde Laboratorium Bouwfysica Kasteelpark Arenberg 40, 3001 Heverlee Universiteit Gent Vakgroep Mechanica van Stroming, Warmte en Verbranding Sint-Pietersnieuwstraat 41, 9000 Gent Universiteit Gent Vakgroep Architectuur en Stedenbouw Plateaustraat 22, 9000 Gent Technische Universiteit Eindhoven Unit Building Physics & Systems P.O. Box 513, 5600 Eindhoven Wetenschappelijk en Technisch Centrum voor het Bouwbedrijf Departement Geotechniek en Structuren Departement Bouwfysica en Uitrustingen Poincarélaan 79, 1060 Brussel Physibel Heirweg 21, 9990 Maldegem

Daidalos Bouwfysisch Ingenieursbureau Oudebaan 391, 3000 Leuven

Ingenieursbureau Stockman nv Muinklaan 6, 9000 Gent

Heat, air and moisture performance engineering A whole building approach SBO project IWT 050154 Tweede jaarlijks rapport Staf ROELS, Erik DICK, Michel DE PAEPE, Arnold JANSSENS, Peter WOUTERS, Benoit PARMENTIER, Jan HENSEN, Bert BLOCKEN, Piet HOUTHUYS, Filip DESCAMPS, Piet DELAGAYE, Demir-Ali KÖSE, Kim GOETHALS, Marnix VAN BELLEGHEM, Mohammad MIRSADEGHI, Daniel COSTOLA, Tadiwos ZERIHUN DESTA, Thijs DEFRAEYE (verslag). September 2008

Inhoud Inhoud......................................................................................................................................... 1 1 Wetenschappelijk- technisch verslag ................................................................................. 3 1.1 Overzicht van uitgevoerde activiteiten....................................................................... 3 WP1.1 Wind pressure distribution ..................................................................................... 4 WP1.2 Driving rain load distribution............................................................................... 17 WP2.1 Development of HAM model............................................................................... 23 WP2.2 Experimental analysis on building enclosures ..................................................... 24 WP3.1 Convective heat exchange and summer comfort.................................................. 32 WP3.2 Development of CFD-HAM model...................................................................... 41 WP4 Towards an integrated approach ............................................................................. 47 WP5.1 Strategic and integrated planning of research activities....................................... 57 WP5.2 Strategic implementation of testing and simulation facilities .............................. 60 References ........................................................................................................................ 61 1.2 Bijsturingen in het project ........................................................................................ 62 1.3 Beheer van het project.............................................................................................. 62 1.4 Haalbaarheid van het project.................................................................................... 63 1.5 Te beschermen resultaten ......................................................................................... 64 2 Utilisatieverslag................................................................................................................ 65 2.1 Valorisatiepotentieel: geactualiseerde visie ............................................................. 65 2.2 Overzicht van de uitgevoerde valorisatieacties........................................................ 67 2.3 Bescherming projectresultaten ................................................................................. 78 3 Financieel verslag............................................................................................................. 79 3.1 Prestatietabel ............................................................................................................ 79 3.2 Prognose voor komende projectjaar......................................................................... 80 3.3 Financiële verantwoording....................................................................................... 81 4 Overzicht .......................................................................................................................... 83 4.1 Wetenschappelijk technisch ..................................................................................... 83 4.2 Valorisatie ................................................................................................................ 87

1 Wetenschappelijk- technisch verslag 1.1 Overzicht van uitgevoerde activiteiten Het onderzoekswerk is georganiseerd in vijf werkpakketten, welke op hun beurt nog verder onderverdeeld zijn: WP1 Outside boundary conditions WP1.1 Wind pressure distribution WP1.2 Driving rain load distribution WP2 Building envelope WP2.1 Development of HAM model WP2.2 Experimental analysis on building enclosures WP3 Building interior WP3.1 Convective heat exchange and summer comfort WP3.2 Development of CFD-HAM model WP4 Towards an integrated approach WP4.1 Development of a prototype software environment WP4.2 Development of a coupling necessity decision procedure WP4.3 Experimental validation WP5 Establishment of a knowledge platform WP5.1 Strategic and integrated planning of research activities WP5.2 Strategic implementation of testing and simulation facilities Dit verslag beschrijft de onderzoeksactiviteiten van het tweede projectjaar lopende van 1 september 2007 tot 1 september 2008. Dit deel van het verslag is opgemaakt in het Engels omdat dit de voertaal is voor publicaties en wetenschappelijke rapporten en een aantal onderzoekers Nederlands niet als moedertaal hebben.

IWT SBO project 050154 – Heat, air and moisture performance engineering - A whole building approach Tweede jaarlijks rapport

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WP1.1 Wind pressure distribution Objectives WP1.1 emphasises the distribution of pressure differences across the building envelope due to wind flow. This subtask is subdivided in two parts: WP1.1.1 Some sets of full-scale measurements will be recorded regarding the wind pressure distribution on the building envelope of the building “WINDHouse” of the Laboratory Structures of BBRI, located in Limelette. The data will be used to asses the numerical predictions with CFD (Computational Fluid Dynamics). WP1.1.2 Numerical simulations of the air flow around a building will be performed. Different hybrid RANS-LES models to describe the turbulence are tested. The calculations will provide, among other numerical results, the pressure distributions at various locations on the building surface. The obtained data will be compared with the experimental pressure data sets provided by WP1.1.1.

Description of work WP1.1.1 Experimental analysis of wind pressure distribution over a building envelope The activities of BBRI-SC during this second year focused on: • The setup of a new measuring system (masts, sonic anemometers, …) • The complete filtering and adaptation of the existing database of pressure measurements on the WINDHouse building for the purpose of this research and in particular for possible comparisons with numerical models developed in WP 1.1.2. The reference building used to define outside boundary conditions is a small house with the dimensions 5x10 m with a roof slope of 30° and a ridge height of 5.2 m. This building was described in a more detailed way in Parmentier (2002). A meteorological mast is installed 30 m upstream of the house in the direction of the prevailing winds. The initial database provided about 600 records of pressure measurements. After filtering of local problems and the check of the self-stationarity of the records (see further), the database consists now of 336 clean records (“runs”) of 15 minutes each. The data collected are: • Pressures on the roof of the building (48 tap locations). • Wind speed at 12 m height upstream of the building. • Wind speed at 5 m height upstream of the building. • Wind direction. The sampling rate of the 51 channels was 20 Hz. All the data were collected by using 5 synchronised data loggers connected to a PC. A dedicated programme was written in VB to pilot the recording phases, the automatic calibration of the pressure transducers and the automatic rotation of the building. The data (18000 for each channel during a complete run) were checked for self-stationarity of the wind speed and wind direction. By using the rotation of the building, the influence of almost all angles of attack (AOA) has been studied (Figure 2).


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Figure 1: The WINDHouse building in Limelette. Angle of Attack vs. Wind speed 20 18 16

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Figure 2: AOA vs. Average wind speed (15’) on the WINDHouse.

The output format of the records was binary to save computer memory. Different Matlab© routines have been developed in order to read the data and analyse it by different ways with a user-friendly interface (see Figure 3 and Figure 4).


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Time-history domain

Frequency domain

Spatial domain (external pressure coefficients, roof) Figure 3: Analysis of the full-scale measurements on the WINDHouse.


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Figure 4: Matlab© routines developed for visualisation/analysis of the data sets.

For each run, pressure results can be expressed as pressure coefficients (differential pressure divided by the dynamic pressure):

CPe =

Pe − P0 0,5.ρ .V 2

where Pe is the external pressure [Pa], P0 is the reference static pressure (in a ground box near the meteorological mast) [Pa], ρ is the air density (1.226) [kg/m³] and V is the wind speed at the ridge of the roof [m/s]. As already reported, there is a clear dependence of the wind direction on the longitudinal turbulence intensity (Iu). This is illustrated in Figure 5. While the roughness category of the Limelette site can be estimated in the range of 30% (category II according to the NBN EN 1991-1-4), the local influence of a group of trees in the North [180°] is evident. These trees were simulated during some tests in a wind tunnel but some blockage effects occurred. 60

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Figure 5: Wind direction vs. longitudinal turbulence intensity (Iu) - U>5m/s.


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Figure 6: North view from the WINDHouse building.

As reported in the first annual report, some discrepancies have been noticed between fullscale (F-S) and model-scale (M-S) measurements. Having this considered, it has been decided to install three additional meteorological masts around the building with specific anemometers in order to get a detailed evaluation of the turbulence intensities of the incoming wind flow around the building. The location of these new masts was determined according to the precision needed by the numerical simulation and to be able to identify the influence of the flow pattern on the windward and leeward pressures. The masts are lattice structures having 10 m height. These masts are now equipped with sonic and 3-cups anemometers. The locations of the masts are illustrated on Figure 7. As it can been seen on this figure, 2 masts are located just near the first existing (original) mast to obtain a spatial grid analysis of the wind flow upstream of the building. A last mast is located downstream, at around 20 m of the WINDHouse building.

Figure 7: Location of the new meteorological masts around the WINDHouse building in Limelette at BBRI. IWT SBO project 050154 – Heat, air and moisture performance engineering - A whole building approach Tweede jaarlijks rapport

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The sensibility to the vibrations of the masts on the measurements has been studied and could be neglected. Hence, in order to evaluate the wind flow with more accuracy, sonic anemometers (SAT) were considered besides 3-cup anemometers (that were used in the past). The main characteristics of SAT’s, cups and propellers are given in Figure 8.

Figure 8: Main characteristics of SAT’s, cups and propellers (Cuerva, Sanz-Andres et al. 2006).

Importance of Sonic anemometry in Wind Engineering The calculation of the atmospheric parameters affecting the performance of structures in the atmospheric flow requires knowledge on the wind speed vector with large time resolution. SAT (see different models in Figure 9) is the most extensively used sensor for this purpose, mainly in places where the turbulent flow is highly 3D, as it occurs in natural complex terrain or in the built environment. SAT’s measure the wind speed in a small volume approaching a single point by detecting the influence of the wind speed field in the transmission of ultrasound pulses along one or more acoustic paths configured by at least one pair of transmitter-receiver transducers (Cuerva and Sanz-Andres 2000). SAT’s present different advantages compared to other types of anemometers (cup, propellers and hot wire). Dynamic effects can be neglected because they do not have any mobile parts. On the other hand, they can measure the 3D wind structure, whereas cups can not and their time resolution is much higher. Although hot wire anemometers can be sampled at high rates (in the order of 10 kHz), their fragility and their need to keep the wire free of deposit and dust prevents its utilisation in outdoor conditions. But what is important for the activities of WP1.1.1 is the fact that the starting threshold and response time of sonic anemometers, for both wind speed and direction, are close to zero (Sturgeon 2005). It means that these SAT’s are very accurate even at very low wind speeds. Hence, applications related to the ventilation and building envelope can be analysed with a high degree of confidence based on the outside boundary conditions measured by the SAT’s. Finally, maintenance of SAT’s is much simpler compared to other anemometers. In general, all SAT’s are calibrated in a wind tunnel. Sonic anemometers are in principle independent of the atmospheric conditions. A misalignment of the anemometer (inclination) can provide a drift of the measurements and some errors in the measurements are also caused by turbulence along the arms (wake) of the transducer for high wind speeds (>60m/s). These different parameters were recently investigated in the framework of the project ACCUWIND (Cuerva et al. 2006) and reviewed by different authors (Sturgeon 2005, Wauben 2005). The influence of temperature, icing, air density, relative humidity or turbulence was analysed by using a “reference” anemometer and different other anemometers (3-cup and sonic) for IWT SBO project 050154 – Heat, air and moisture performance engineering - A whole building approach Tweede jaarlijks rapport

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comparison. The conclusion was that this influence could be neglected, within the activity range of our project. Finally, the comparison between 3-cup anemometers and sonic was excellent, above a specific value of the wind speed.

Figure 9: Different models of Sonic anemometers (Cuerva, Sanz-Andres et al. 2006).

After an analysis and a comparison of the materials available, 2 WindMaster Pro Ultrasonic anemometers from Gill Instruments Ltd were bought (Figure 10). According to the supplier (Gill Instruments 2007), the resolution is < 0,01m/s and the accuracy if lower than 1,5% RMS. A check of the whole measuring and DAQ system was performed in the laboratory (see Figure 11).

Figure 10: WindMaster Pro Ultrasonic Anemometer (Gill Ltd) and sonic theory.


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Figure 11: Check of the installation of the sonic and 3-cup anemometers at BBRI.

Additional 3-cup anemometers were also bought to obtain information on the wind speed along the altitude around the building. Future activities From a technical point of view, the first database of measurements on the WINDHouse building is ready to be used. A specific interface was developed to compare more easily with numerical simulation results. During the next months, a close cooperation with the team dealing with WP 1.1.2 will be organised. Based on the comparison with specific “runs”, it should be possible to define a reference for calibration of the simulation models. Moreover, new measurements will be performed on the facades on the WINDHouse building, together with measurements of the wind structure with the new measurements grid and in particular with the above mentioned sonic anemometers. It is expected that a complementary set of records will be available in April 2009. VRT building (Daidalos) It was decided to include also the measurement results from the VRT building (performed by Daidalos) in the analysis of this workpackage. The data can be used as a realistic test case for numerical simulations. The measurement campaign involves a large building where detailed wind speed measurements are performed close to the façade, simultaneously at 6 points. These measuring locations are changed frequently during the measurement period and also a wind mast on the roof top is used as a reference. WP1.1.2 Development of a hybrid RANS-LES technique of flow over buildings From a computational point of view it is not feasible to perform Large Eddy Simulations (LES) of flow around buildings (LES = resolving the large turbulence structures in the flow and modelling the small structures). A very fine mesh near the building walls is required to accurately resolve the flow. This leads to very large computational costs. At the other hand, simulations with Reynolds Averaged Navier-Stokes equations result in very poor predictions of the flow field over a building (RANS = modelling all the turbulence structures). That is the main reason for the development of hybrid models. In such a model an unsteady Reynolds Averaged Navier-Stokes (RANS) model is used in the near-wall regions, while far from the wall a sub-grid scale (SGS) model is used within a LES-formulation. In this way the best IWT SBO project 050154 – Heat, air and moisture performance engineering - A whole building approach Tweede jaarlijks rapport

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qualities of RANS and LES are combined in one model. The use of a RANS model in the near-wall regions allows using much coarser meshes in those regions and this saves computational time. Obtained results During the second project year, many hybrid models have been investigated, including the more-or-less standard Detached Eddy Simulation (DES) model of Spalart et al., the k-l model of Davidson, and the k-l model of Tucker and the hybrid model developed by our own research group (C. De Langhe): ε-l model. Since only the DES model is implemented in Fluent, the other models needed to be programmed. This has been done by writing User Defined Functions (UDF). In the first project year, we tested the DES of Spalart, the k-l of Davidson and the ε-l model on flow over a periodic part of a square section of a tower building. In the second project year, we found that this test case is extremely delicate. To obtain good results, very fine grids are necessary. This is due to the extreme large scale time-dependency of the flow caused by large-scale vortices. Therefore, the test case was changed to a cube on a flat plate. There is one well-known test case documented in the literature. The test case is more representative for a building of limited height, and is therefore more appropriate for the project. This case is less sensitive because the boundary layer stabilizes the flow, so that the flow is less timedependent. Very coarse grids were tested, as typically used in RANS-simulations: 250000 to 500000 cells. Velocity profiles are available for a number of stations on the cube and in the wake of the cube. The pressure distribution is available on the flat plate around the cube, but not on the cube itself. RANS-simulations. RANS-simulations were tested in steady flow, as most often used in practice for determination of the flow field around a building. Basic RANS-models lead to bad results, but there are possibilities to ameliorate the performance of RANS-models. Two ameliorations suggested in the literature were investigated. The first amelioration is to introduce the wall shear stress as boundary condition at walls, instead of a zero velocity boundary condition. This is a typical practice in high-Reynolds formulations, where the grid in wall vicinity is very coarse. Proposals exist for a blended calculation of the wall shear stress such that simulations are possible for grids that are rather fine in wall vicinity. We need this possibility, as it cannot be hoped that good results can be obtained with extremely coarse grids. Several proposals in the literature were investigated and an own variant was developed. The second amelioration consists of bringing in a model for the source term in the equation for turbulent kinetic energy, instead of calculating the source term directly, which becomes quite inaccurate on coarse grids. This is also a practice used with the high-Reynolds form of RANS-models, where the grid in wall vicinity is coarse. Here, proposals of blended formulations of such a term were investigated, so that the model can be used on fine grids and as well on coarse grids. Again, we developed an own variant. The ameliorations result in an improvement of the velocity prediction in the vicinity of the cube. The prediction of the flow in the wake of the cube remains bad. The prediction of the pressure distribution on the flat plate in the vicinity of the cube is very good. This good pressure distribution on the plate is, of coarse, not a guarantee for a good pressure distribution on the cube itself, but a reasonable conclusion is that the pressure distribution on the cube cannot be very bad, since the velocity distribution in the vicinity of the cube is quite good, although not perfect. Hybrid RANS/LES-simulations. Hybrid simulations result in a very good prediction of the velocity field in the vicinity of the cube and a good prediction of the velocity field in the wake IWT SBO project 050154 – Heat, air and moisture performance engineering - A whole building approach Tweede jaarlijks rapport

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of the cube. The blended formulations of the wall shear stress (WSS) and production term (PK) in the RANS-part of the simulation contribute also to the quality of the predictions. However, the major difference between a steady flow RANS simulation and an unsteady flow hybrid RANS/LES simulation is caused by taking into account the unsteadiness of the flow. In the formulations that we tested, unsteadiness comes in through length scale limitation in the modelled turbulence away from walls. In this sense, the simulations can also be called unsteady RANS simulations. The RANS model is not changed for use in the LES zones, but by limitation of the length scale. The pressure distribution on the plate around the cube is less good with the hybrid simulations than with the RANS simulations. This observation is very confusing. Our expectation is that the pressure distribution on the cube is better with a hybrid simulation since the velocity field in the vicinity of the cube is much better, but this conjecture cannot be verified with the data of the test case. LES-simulations. The available LES models in FLUENT were tested: the constant coefficient Smagorinsky model and the dynamic coefficient k-model. The results of the LES simulations on the coarse grids that are used, are not really bad. The predicted velocity profiles in the vicinity of the cube are not bad, but not as good as with the hybrid simulations. The predicted velocity profiles in the wake are very good. The pressure distribution on the plate is not good. Moreover, on the coarse grid that was used, the results are not very sensitive to the particular LES subgrid model. Without any model, the results are not significantly different. This means that the results are very much polluted by numerical dissipation. The grids that are tested are thus much too coarse for a reliable LES simulation. So, this observation is a very strong argument for the use of hybrid RANS/LES simulations. Furthermore, the results obtained with LES prove that taking into account the flow unsteadiness is vital for good predictions. Practical conclusion on hybrid RANS/LES simulation. From the study in the second year, the conclusion definitely is that only hybrid RANS/LES is a practical method for simulation of the flow around a building, using rather coarse grids. From our study is concluded that the most practical way to come to a hybrid simulation is to use a RANS model as subgrid model in the LES part by limiting the length scale according to the grid size. Terms currently coming into use for such an approach are URANS (unsteady RANS) or seamless hybrid RANS/LES. An older term is DES (detached eddy simulation). DES is associated most often to the Spalart-DES approach, but can also be seen as general approach to switch to LES in detached flow zones starting from any turbulence model by changing the length scale of the model. It is also found that ameliorations in the RANS-part concerning the wall shear stress boundary condition (WSS) and the production term of the turbulent kinetic energy (PK) improve the quality of the simulations. Note that WSS and PK ameliorations are already implemented in FLUENT in the enhanced wall functions option. These ameliorations are not identical to the ameliorations that are developed in this workpackage, but the precise formulation is not critical. Therefore, the DES-SST model in FLUENT was tested together with the enhanced wall functions option. The basis of the model is the SST-k-ω model, which is known to be one of the best RANS turbulence models. The DES-hybridisation means that the length scale is limited by the grid size, when this one becomes smaller than length scale predicted by the model. The conclusion is that the DESSST simulation leads to results that are comparable to the results obtained with our own hybrid variants. So, for use by other partners in the project, DES-SST with enhanced wall functions is recommended.


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Example The cell distribution around the cube for the coarse mesh is shown in Figure 12.

Figure 12: Cell distribution for the coarse mesh used in the simulations.

In Figure 13, the effect of the modifications on the RANS predictions is shown. Red lines represent the standard k – ε model, the blue lines the same model but with WSS and PK ameliorations.

Figure 13: Comparison of RANS (red lines) and RANS + WSS + Pk (blue lines) with experiments at 2 locations in the symmetry plane.

Pressure profiles on the channel base plate are given in Figure 14. Left is the standard k – ε model, right is the same model with WSS + PK amelioration.


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Figure 14: Cp profiles on the channel base plate with RANS. The empty circles represent experimental data at X/H = -0.06, the empty squares those at X/H = 0.5, the black triangles those at X/H = 1.06 and the empty diamonds those at X/H = 1.22. The respective colored symbols are the simulation results.

The DES–SST simulation results are presented in Figure 15. The red lines represent the hybrid model with WSS + PK amelioration as in FLUENT while the blue lines represent the results with our own method for WSS +PK.

Figure 15: Comparison of DES-SST with ameliorations as in FLUENT(red lines) and with own modifications (blue lines) with experiments.

Finally, in Figure 16, the pressure distributions for both models are presented.


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Figure 16: Pressure distributions for the DES-SST model. Left: with ameliorations as in FLUENT, right with own modifications.

Deliverables WP1.1.1 • The test setup for the WINDHouse is operational. • The complete filtering and adaptation of the existing database of pressure measurements on the WINDHouse building is performed. WP1.1.2 • Several hybrid techniques were evaluated. Some were available in the software while others were implemented by the researcher. Out of this extensive study, the most accurate technique was identified.

Planning WP1.1.1 • A measurement campaign will start for the WINDHouse. • A measurement campaign on the VRT building is planned WP1.1.2 • Test data for flow over a cubic building of 6 m x 6m x 6 m is found in literature. The pressure distribution is available on two cuts of the cube: with the vertical symmetry plane in flow direction and with a horizontal plane. These data will be used for further validation of the obtained results with the aim to come to a final conclusion on the use of hybrid methods for analysis of flow over a building. • The WINDHouse of the BBRI will be simulated using the data as available from the BBRI. • The VRT-building will be simulated and results will be compared to the data from the measurement campaign of Daidalos.


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WP1.2 Driving rain load distribution Objectives WP1.2.1. Laboratory and in situ experiments of contact phenomena of driving rain impinging on different building materials. The final amount of water that may enter the building enclosure (the boundary conditions for the building envelope model) will be determined by splashing effects, adhesion, evaporation, run-off and capillary absorption. All these phenomena strongly depend on the material properties of the building enclosure. Parameters are porosity of the material, moisture capacity, capillary activity, …. WP1.2.2. Development of a water uptake and run-off model for building materials. Numerically, the transformation of individual rain drops, absorbed by the building material towards a smeared wetting as assumed in building envelope models, will be investigated. In addition, starting from the work of Kondic (2001) a run-off model for rain water run-off on capillary active materials will be developed. (Blocken et al. 2003) developed a simple preliminary model, combining a model for capillary absorption and for rain water run-off using the thin film theory. This model however showed to be very time consuming due to the time scale difference between the development of a film and the capillary absorption. The research of the previous two sections of this subtask (WP 1.2.1 and WP1.2.2) was conducted in strong collaboration with a PhD student working on a KUL OT-project where the contact phenomena (bouncing, splashing and spreading) and surface phenomena (absorption, evaporation and run-off) are also of interest. Out of this research it has become clear that the outside boundary conditions, namely convection and radiation, have a large impact on the evaporation at building facades wetted by wind-driven rain. Therefore the focus of the PhD student that is involved in this SBO project (PhD1) will be mainly on these topics and an additional subtask (WP1.2.3) has been introduced below. WP1.2.3. Numerical and experimental analysis of convective heat and mass transfer at exterior building surfaces. More accurate predictions of the convective transfer coefficients are obtained, considering the influence of wind speed, wind direction and building surroundings and spatial distribution across the surface. Also the influence of specific materials and surface texture is investigated.

Description of work WP1.2.1. Laboratory and in situ experiments of contact phenomena of driving rain impinging on different building materials. As mentioned in the previous report, a laboratory set-up was used to study contact phenomena of raindrops impinging on a building material. With this set-up, raindrops of different sizes were released from a certain height until they reached terminal velocity after which they impinge on the building material. As the raindrop trajectory was captured by a high-speed camera, the different types of contact phenomena could be distinguished, namely bouncing, splashing and spreading (Figure 17). The data obtained with this measurement setup were processed in detail (Figure 18), which led to more insight regarding influence of impact angle, impact speed and droplet diameter on the spreading length and width of a single droplet.


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Figure 17: Photos of wetted areas on ceramic material surface: (a) Spreading: d = 2.0 mm, v = 6.8 ms-1 , θ = 90.0°; (b) Bouncing: d = 2.0 mm, v = 6.8 ms-1 , θ = 24.5°; (c) Bouncing: d = 3.9 mm, v = 7.5 ms-1, θ = 90.0°; (d) Splashing: d = 3.9 mm, v = 7.5 ms-1, θ = 15.0° (d = droplet diameter, v = impact speed, θ = impact angle).

Figure 18: Dimensionless maximum spreading length Ls (a) and spreading width Ws (b) versus impact angle θ (d = drop diameter (mm), v = impact speed (ms-1)). Each symbol represents data of a single drop. 3 drops bounced and 6 drops splashed, whereas all other drops spread.

An experimental setup (Figure 19) for field measurements of wind-driven rain loads and the response of walls was developed at the VLIET building for validation purposes (see previous report). Measurements of near-wall wind speed and direction, WDR intensity, material weight and temperature are possible. Detailed measurement campaigns were performed last year, capturing several rain events. Thereby large datasets are provided (Figure 20) which can be used for validation of numerical simulations.


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Figure 20: Measurement results during two rain events (Wmea: weight change of the specimen, SWDR,mea: cumulative amount, IWDR,mea: intensity of wind-driven rain).

WP1.2.2. Development of a water uptake and run-off model for building materials. The simple run-off model that was implemented in HAMFEM, which is an in-house HAM modelling tool developed by the Laboratory of Building Physics at the K.U.Leuven, was extended. Now the model includes the effects of evaporation and absorption by the material on the run-off progression which results in more realistic modelling of this phenomenon (simulation example: Figure 21).


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Figure 21: Numerical simulation with run-off model.

WP1.2.3 Laboratory experiments and numerical modelling of the influence of outside boundary conditions on the heat and mass transfer at building façades wetted by wind-driven rain. As mentioned before, the effect of the outside boundary conditions, such as convection and radiation, was found to be of significant importance in the assessment of the response of building walls after a rain event for simulations such as described in WP1.2.2. Therefore, WP1.2.3 was created. In a first stadium, only convective heat and mass transfer was considered and only forced convection was taken into account. A numerical study with CFD was carried out to asses the convective heat transfer on a 10 m high, cubic building placed in an atmospheric boundary layer. The RANS approach was used to model turbulence. In order to resolve the boundary layer, the commonly used wallfunction modelling technique was compared with the low-Reynolds number modelling approach. The latter however requires a very high grid resolution in the boundary-layer region. First, the used numerical techniques were validated with experimental data for flow over a heated cube placed in a turbulent boundary layer at low Reynolds numbers. Fairly good predictions of the CHTC could be obtained for windward and leeward facades with the lowReynolds number modelling approach. From the results, it is suggested that the conventional wall-function modelling technique should not be used to predict the CHTC. Wall functions are found to model the inner part of the boundary layer not accurate enough. The prediction of heat transfer in this region is however found to have a large impact on the CHTC. Therefore the influence of roughness can also have a significant influence on the CHTC and simulations will be performed to clarify this. For the cubic building, the CHTC was correlated with the mean wind speed at a height of 10 m above the ground but, in contrast to previously used correlations, the spatial distribution across the façade was also taken into account by which correlations on each location on the building façade could be obtained (Figure 22). Moreover, the sensitivity of the convective heat transfer coefficient to the approach flow profile, wind direction and thermal boundary conditions was investigated.


20

Figure 22: Distribution of the correlation of the CHTC (power law with coefficients C and B) with the wind speed (U10) over the windward façade of a cubic building.

An experimental setup was built, namely a small atmospheric boundary-layer wind tunnel with a test section of 0.5x0.5m² and a wind speed range from 1-12 m/s. It will be used to validate the numerical techniques for the previous problem at higher Reynolds numbers. It will also be used for the study of other problems, such as the effect of shelter of surrounding buildings on the CHTC distribution. Both temperature and velocity measurements will be performed. A study of the effect of convection on combined heat and mass transfer in porous materials was also within the scope of this workpackage. Solving mass transfer in porous materials (which involves both liquid and vapour transport) is not possible with the CFD software that is used. Therefore the CFD code is coupled (explicitly) with HAMFEM (Figure 23). The air flow is entirely resolved within the CFD package whereas the heat and mass transport in the porous material is resolved within HAMFEM. Preliminary validation simulations have been carried out in order to validate the coupled program. More extensive validation and verification is planned. Moreover, the program will be further developed in order to study more complicated geometries.


21

Figure 23: Coupling procedure of CFD program with HAMFEM.

Deliverables WP1.2.1 • The experimental setup for field measurements regarding wind-driven rain loads at the VLIET building was used to gather detailed datasets for several rain events. WP1.2.2 • A more extensive run-off model is developed which takes into account the effect of evaporation and absorption on the run-off process. WP1.2.3 • Validation of the numerical methods was performed. • A study of the CHTC on building surfaces was conducted by which more detailed information regarding the wind direction and the relation with the wind speed was provided. • An experimental setup has been constructed for CFD validation and for analysing the influence of different parameters on the CHTC distribution on facades at high Reynolds numbers.

Planning WP1.2.1 • The experimental setup will be used to obtain more datasets during rain events. WP1.2.2 • No further actions are planned for the coming year. WP1.2.3 • Wind-tunnel tests are planned regarding the CHTC on building surfaces • The coupled CFD-HAM model will be further verified and validated. • Numerical simulations considering the effect of micro roughness on heat and mass transport are planned.


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WP2.1 Development of HAM model Objectives The aim of this subtask is to develop a comprehensive building envelope model for the coupled analysis of heat, air and moisture transport through building enclosures. The model will be based on existing scientific models available from the partners. Because of the different time-scales between heat, moisture and air transport, and the associated numerical obstacles, a stabilised solution method could not be achieved when dealing with air transport. Therefore the main objective of this subtask is to tackle this problem.

Description of work The researcher is studying different numerical modelling techniques and gathered information and knowledge on existing HAM-models with a particular emphasis on the HAM-modelling program HAMFEM, developed at the KULeuven. There is a need to incorporate air transport in the heat and moisture transfer model. In order to attain more insight in the complexity of HAM-modelling and to overcome the difficulties in numerically solving the combined HAMproblems further research need to be conducted.

Deliverables •

Due to the fact that the initial researcher left the project and a new researcher started only some months later, there are no deliverables at this stage of the research

Planning • • •

Some possible numerical techniques will be checked in a simplified MATLAB code. Afterwards based on the results, the most optimal method will be implemented into HAMFEM. A review paper will be prepared about the existing HAM modelling techniques. The experimental setup at the VLIET building (WP2.2) will be simulated with HAMFEM (without air component) and comparison will be made with the available measurement data in order to evaluate the effect and importance of airflows and/or air leakage through the building wall. In a later stage of the project the ‘upgraded’ version of HAMFEM will be used to fully simulate heat, air and moisture transfer in building components.


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WP2.2 Experimental analysis on building enclosures Objectives This subtask focuses on the analysis of HAM transport through building enclosures based on measurement data. It was decided to limit the experimental analysis of this workpackage to the VLIET building of KULeuven. The experiments are conducted in a wall of the row house constructed in the previous year (see the report of 2007). The obtained data can be used to get physical insight about the HAM transport phenomena and as a validation tool for the numerical model to be developed under WP2.1.

Description of work During the first year, a test-setup was built at the VLIET-building of the K.U.Leuven in Heverlee (Figure 24). In the building, a terraced house has been constructed (see the report of 2007)

Figure 24: Schematic representation of the VLIET-building and the terraced house.

In this project year, a test wall at the north east side of the terraced house has been constructed. The constructed test wall is a lightweight wall divided in three different parts. In all parts, the necessary measuring devices were installed. This section describes the test setup and depicts the first measurement analysis. WP2.2.1 Temperature, humidity and heat flux measurement The experimental set up is installed in one of the VLIET building walls (Figure 25). The considered wall is subdivided into three vertical parts (left, central and right). The left wall is air and vapour open at the inside, the right part is airtight but vapour open (gypsum board at the interior). Each part contains three measuring rows (top, middle and bottom).


24

Left part y Central part

z x

Right part

Top row

Middle row

y

y

Bottom row

y

x

x

x

Figure 25: The test wall of The VLIET building.

In the wall a total of 57 thermocouples, 18 humidity sensors and 12 heat flux sensors are mounted. The sensors are distributed in top, middle and bottom rows of the wall. Figure 26 shows a section through the wall and heat flux sensors distributions in it. Similarly, but not exactly, thermocouples and humidity sensors are also placed in the wall. 60

60

60

Cavity ●►▼

●►▼

►

►

●►▼

Celit 3D Insulation fibre

Wooden board

Left part

►

Central part

Gypsum board

Right part

● installed in top row ► installed in middle row ▼ installed in bottom row

Figure 26: Schematic representation of the wall and heat flux sensors distribution.


25

Figure 27: Heat flux sensor arrangement.

Temperature, humidity and heat flux data are available since December 2007. The data are collected continuously with a sampling rate of 10 min-1. WP2.2.2 Thermal analysis Thermal resistance Thermal resistance is a measure of a material’s ability to prevent heat from flowing through it; the parameter can be determined using theoretical and experimental methods. a) Theoretical method n d Rtheo = ∑ i i =1

λi

where Rtheo [m2K/W], d [m] and λ [W/mK] are theoretical thermal resistance, thickness and thermal conductivity of material i. b) Experimental methods There are two different ways to obtain the thermal resistance from measurements: • The slope method: ΔT Rs = i qi Where ∆Ti [K] and qi [W/m2] are measured temperature difference and heat flux across the considered wall respectively. The slope of the linear fit between qi and ∆Ti gives the thermal resistance, Rs. Here the thermal resistance between the interior finishing (gypsum board or wooden finishing) and the Celit 3D material is calculated for the middle row wall for left, central and right parts. Daily averaged data is used for the analysis. IWT SBO project 050154 – Heat, air and moisture performance engineering - A whole building approach Tweede jaarlijks rapport

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22 20

data

Δ Ti = 5.66*qi

18

Δ T [K]

16 14 12 10 R2 = 0.82

8 6 1.6

1.8

2

2.2

2.4

2.6 q [W]

2.8

3

3.2

3.4

3.6

Figure 28: Linear correlation between qi and ∆Ti in December 2007 (left part of the wall).

•

Direct method n

Rd =

∑ ΔT

i

i =1 n

∑q i =1

i

The quotient between the sum of the temperature differences and the sum of the heat flux data gives the thermal resistance, Rd. Table 1: Theoretical and measurement based R-values [m²K/W] at the middle row of the walls.

December 2007 January 2008 February 2008 March 2008 April 2008

Left wall Rs 5.6611 Rd 5.6135 Rtheo 5.3078 Rs 5.1286 Rd 5.1535 Rtheo 5.3078 Rs 5.8857 Rd 5.8978 Rtheo 5.3078 Rs 5.4738 Rd 5.5786 Rtheo 5.3078 Rs 6.6005 Rd 6.0746 Rtheo 5.3078

Central wall 6.1824 6.1780 6.0812 5.9197 5.9420 6.0812 6.1146 6.1370 6.0812 5.8571 5.9685 6.0812 5.6070 6.0025 6.0812

Right wall 6.5367 6.5426 5.3078 6.2837 6.3064 5.3078 6.5595 6.5868 5.3078 6.2144 6.3136 5.3078 6.0279 6.3852 5.3078


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7

Rs Rd

6

Rtheo

R [m2.K/W]

5

4

3

2

1

0

Left part

Central part

Right part

Figure 29: R-values using the three methods (mean values over the four months).

In Figure 29, the theoretical and measurement based methods provide comparable R-values for the left and central part of the wall. However, there is a significant discrepancy between the results of the two methods for the right wall. Moreover both the measurement based techniques (the slope and the direct methods) resulted in R-values of the right part of the wall greater than the central part, which is not realistic since the central part contains an extra air cavity (Figure 26). The possible cause of the disagreement between the theoretical and measurement based methods at the right wall will be further investigated. Buoyancy effects Buoyancy, if present, influences heat transfer through building walls. This influence can be assessed qualitatively with a temperature ratio, a dimensionless number which varies between zero and one. Top row

Te

Tx2

Tx1

Middle row

Ti Bottom row

Insulation fibre Figure 30: Illustration for temperature ratio computation. IWT SBO project 050154 – Heat, air and moisture performance engineering - A whole building approach Tweede jaarlijks rapport

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Tx1 − Te T −T ⎫ , τ x 2 = x 2 e ⎬ → Ti ≠ Te Ti − Te Ti − Te ⎭ where Te [°C] is temperature at the outside surface of the Celit 3D material. Ti [°C] is the wall surface temperature in the room side and Tx [°C] is temperature in the insulation fibre (Figure 26).

τ x1 =

The presence of buoyancy effects is analysed through the temperature ratio at both sides of the insulation layer by comparing the top, middle and bottom values. Month = Jan. 08 Top

Left wall

Middle Bottom 0.1

τx1

0.2

0.3

0.4

τx2 0.5

0.6

0.7

0.8

0.9

1

0.9

1

0.9

1

Top

Bottom 0.1

τx1

Central wall

Middle

0.2

0.3

0.4

τx2

0.5

0.6

0.7

0.8

Top

τx1 Middle Bottom 0.1

Right wall 0.2

0.3

0.4

τx2

0.5

0.6

0.7

0.8

τ Figure 31: Temperature ratio for the three parts of the wall.

In Figure 31 no buoyancy effects can be observed. If buoyancy effects are present, the highest temperature ratio values would occur on the top row followed by the middle row of the wall, indicating the rise of warm air from the bottom. WP2.2.3 Moisture absorption measurement Nine removable, moisture capturing tiles with a commercial name of Celit 3D are used for the analysis. The test set up is shown in Figure 32.


29

Removable nine moisture capturing tiles (Celit 3D) are installed to quantify moisture transfer

20

20 cm

Ce lit

cm

3D

D 1.7 cm

Celit 3

Figure 32: Experimental set up for moisture measurement.

The measurement procedure is highlighted below: • The nine Celit 3D material kept in the wall for a specific period of time in order to capture moisture (hygric buffering and interstitial condensation) • The material is removed for measurement • The material is weighed and the data are stored • From the successive weight measurements the amount of migrated moisture is quantified as: Moisture contenti =

mtot , i − mdry , i mdry , i

where: mtot,i is total mass of the ith material(g) mdry,i is dry mass of the ith material (g)


30

0.06

L/T L/M L/B C/T C/M C/B R/T R/M R/B

Moisture content [g/gDW]

0.05

0.04

0.03

0.02

0.01

0

16/06 20/06 23/0627/0630/06 04/07 10/07 18/07 25/07 01/0810/08 15/08 22/08 Day/Month

Figure 33: Normalised mass of migrated moisture.

In Figure 33 abbreviations L, C and R stand for left, central and right parts of the wall respectively. Whereas T, M, B are for top, middle and bottom row of the wall respectively.

Deliverables • • •

Measurement data is available. Data processing methodology is in place. The data are partially analysed and interpreted.

Planning • • • •

Further thermal and moisture analysis will be conducted using updated experimental data. Natural and forced ventilation system will be installed in the row house. These all strongly determine the air flow and hygric behaviour of the test walls. New campaign of experiments, data analysis and result interpretation will be performed. A test set up will be prepared to study air permeability of the Celit 3D tile. Occurrence of interstitial condensation inside the Celit 3D material will be checked in the winter season.


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WP3.1 Convective heat exchange and summer comfort Objectives WP3.1 will focus on the convective heat transfer in rooms and offices and its impact on summer comfort performances by solar processing, intensive (night) ventilation and thermally active flooring. Engineering the summer comfort performances depends on the other hand to a large extent on a reliable prediction of the local heating through solar irradiation and the prediction of wind pressures around buildings for ventilation (WP1.1). WP3.1 is subdivided into four parts: WP3.1.1 An experimental analysis of convective heat transfer between the ventilation air and the building surface will be performed. This work focuses on a single zone and will be done in the rotating PASLINK-cell available at BBRI, a highly instrumented test facility. WP3.1.2 An experimental analysis of solar heating and intensive ventilation and its impact on summer comfort will be conducted. WP3.1.3 A numerical prediction of ventilation and local heating through solar irradiation inside buildings will be performed. The solar illuminated patterns on inside surfaces through direct solar radiation will be calculated and converted to local heat powers. For the ventilation, input data from WP1.1 will serve as boundary conditions. The CFD simulations will be coupled with a multi-zone building simulation model and the predictions will be validated by comparison with the test results. WP3.1.4 The numerical methods that are developed will be validated with data measured in projects realised by the industrial partners.

Description of work WP3.1.1 Experimental analysis of convective heat transfer between the ventilation air and the building surface It has to be noted that the content of this subpackage has been extended. Now also a numerical analysis (described below) is included in addition to the experimental analysis. Ideally, to predict the building performance in detail is to solve the conservation equations for the temperature and the velocity fields for the room that is of interest. However, because of high computational costs of Computational Fluid Dynamics (CFD), multi-zone energy simulation is currently appraised. An important component of building energy analysis is the prediction of interior convective heat transfer. The convective heat transfer coefficients (CHTC’s) are mostly derived from data based on experiments with stand-alone surfaces. Recently there is a trend to develop new CHTC’s for real building surfaces according to the flow regime in the room – as reviewed by Sacré et al. (2007). Consequently a study (Goethals and Janssens 2008a) is performed to further examine the sensitivity of the predicted performance by ES to the modelling of convective heat transfer. Simulations of a night cooled office are carried out in TRNSYS during the Belgian summer. The examined room is based on the model described by Breesch (2006). In this particular case of night cooling, accurate modelling of convective heat transfer is extremely important, because the CHTC’s should be considerably higher than those normally used. The influence of the CHTC correlations, extracted from literature, is evaluated for the summer comfort – IWT SBO project 050154 – Heat, air and moisture performance engineering - A whole building approach Tweede jaarlijks rapport

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weighted temperature excess method (GTO) and adaptive temperature limits method (ATG) – and the saved cooling demand of the night purging. Besides, a parameter study is performed in order to examine the sensitivity to the applied convection algorithm. As shown in Table 2 – in which the GTO are given in absolute values and relative to the base case – the predicted performance is strongly affected by the choice of the CHTC. The choice of the correlation is of the same importance as the choice of e.g. internal heat gains or sun blind control. Clearly, a more exact definition of the CHTC applicable for the case at hand is necessary. Table 2: Results of building simulation of parameter study.

base case internal heat gains = 21.7W/m² air tightness n50 = 1h-1 gsunblinds = 0.3 instead of 0.17 ΔTnight = 3K instead of 2K Irradiance controlling blinds = 300W/m² instead of 150 W/m² Ti,min_night = 18°C night ventilation rate = 6ACH

GTO (h) Awbi&HattonprEN ISO13791 natural 45 117

BeausoleilMorrison 52

5 (11%)

32 (27%)

12 (23%)

64 (142%) 63 (140%) 76 (169%)

159 (135%) 150 (128%) 169 (144%)

68 (131%) 69 (133%) 88 (169%)

148 (329%)

271 (232%)

145 (279%)

46 (102%) 67 (149%)

119 (101%) 148 (126%)

52 (100%) 87 (167%)

As a cost-effective alternative to experimental determination, CFD can provide new CHTC correlations. However, experience indicates the limitations of the current available CFD methods with respect to the reliability and the sensitivity, and the necessity to validate CFD results. Together with the governing equations, the description of the boundary conditions determines for a larger part the reliability and the accuracy of CFD simulations – as identified in the IEA Annex 20-project (Lemaire 1993). Correct modelling of the supply air boundary condition is regarded most crucial. However, because of the large scale-difference between the diffuser and the room, it is necessary to make an approximation and simplification of the complicated supply geometry, admitting the use of a coarser mesh. Therefore, a literature review of diffuser models is performed (Goethals and Janssens 2008b). The solutions to model a diffuser can be divided into two groups. In the first approach, the initial jet momentum of the diffuser is imposed directly at the supply opening. This group includes the simplified geometrical model and the momentum model. On the other hand, the box model and the prescribed velocity model are part of the momentum modelling in front of the air supply diffuser plane. In addition to this literature review, the influence of diffuser models on the predicted CHTC is studied using CFD (Goethals and Janssens 2008c). Numerical simulations of a modified version of test case E.2 of the IEA Annex-project – as shown in Figure 34 – are performed. The above mentioned models are applied to simulate the complex HESCO-type nozzle diffuser.


33

2.5m

0.2m 0.6m

Y X

4.2m

Z

Figure 34: Configuration of the test room of test case E.2 and the HESCO nozzle diffuser (Heikkinen 1991).

In this study the commercial CFD program Fluent is used. In the case of Fluent, the computational results depend crucially on the grid, since the finite volume method is applied to discretize the simulation domain. Thus, the grid has to be designed in such a manner that it does not introduce errors that are too large. Besides a good grid quality, the resolution of the grid should be fine enough to capture the important physical phenomena like shear layers and vortices. Therefore, the necessary resolution is analyzed using an extensive grid convergence study. To estimate the numerical error of a given result, attributed to the finite resolution in space, generalized Richardson extrapolation should be tried. For the Richardson extrapolation, at least solutions (fi) on three systematically refined/coarsened grids are necessary. Here, i=1 denotes the fine, i=2 the medium and i=3 the coarse grid. Moreover, the solutions have to display monotonic convergence. From the ratio of the solution changes (R) three different behaviours can be discerned – as described in Table 3. Clearly, monotonic convergence is very difficultly obtained. In this case, only one solution of two temperatures and the CHTC of the finest grid set display monotonic convergence. As for the other temperature and the velocity magnitudes, oscillatory behaviour is observed. Analysis of the test case is restricted to the finest grid of this set because of computational limits. An inter-model comparison shows a relatively great influence of the diffuser model on the predicted CHTC. The predicted CHTC values deviate up to 61% from the results obtained with the box model – which is assumed the most appropriate for this type of diffuser according to Srebric and Chen (2002). Additionally, the calculated heat fluxes are compared with results based on empirical correlations – found in Sacré et al. (2007). Only the box method and the prescribed velocity model produce results which are in reasonable agreement with the appropriate convection algorithms – as shown in Figure 35.


34

Table 3: Results of convergence study. R=

(f (f

2 3

− f1 ) − f2 )

: monotonic convergence : oscillatory convergence grid set : divergence v (1.4,2,0) v (3.0,2,0) CHTCceiling T(1.4,2,0) (K) T(3,2,0) (K) (W/m²K) (m/s) (m/s) 144x81x63 -0.550 -0.641 -0.604 -0.859 -0.794 162x99x72 2.813 37.995 -11.143 -20.091 3.213 171x99x72 -0.715 -0.200 0.004 -0.037 0.141 0 1

12

qsouth wall (W/m²)

10

Alamdari&Hammond Awbi&Hatton-natural

8

Beausoleil-Morrison Simplified geometrical

6

Momentum 4

Box Prescribed velocity

2 0 0

1

2

3

4

5

ΔT (K)

Figure 35: Convective heat flux at the south wall: empirical correlations and simulated values.

In order to validate the reliability and sensitivity of CFD modelling, the CFD results will be compared with experimental data. Since convective airflows are highly influenced by the geometry and the dimensions of the space, experiments have to be carried out in full-scale facilities, like the PASLINK cell. Therefore, a preliminary feasibility study of the PASLINK cell is performed in CAPSOL (Goethals and Janssens 2007). Moreover, the influence of adding thermal mass to the inside of the PASSYS cell is studied by simulating an a-periodic change. WP3.1.2 Experimental analysis of solar heating and intensive ventilation and its impact on summer comfort Because the modelling of multi-zone set ups is impossible considering the calculation time needed to perform CFD simulations, the experimental study will be performed in the PASLINK cells at Limelette. The results and conclusions drawn from this will provide necessary information for multi-zone models. At Limelette, one test cell will be used as reference while the other will be adapted to fit the experiments. In both, the air handling unit will be enclosed by a new wall, dividing it from the actual test room. In the new wall, openings will be installed at different locations: one near the ceiling, symmetrically placed between the side walls, two openings near the floor of which one near the wall and the other in the middle. It is considered necessary that the upper and lower openings can be used as inlets. Furthermore, it should be possible to use every opening as an outlet. Considering the inlet type, a basic supply diffuser, such as a grille diffuser, can IWT SBO project 050154 – Heat, air and moisture performance engineering - A whole building approach Tweede jaarlijks rapport

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be used. The window can be covered by using an outside box. In the test cell thermal mass can be added: a concrete floor or a wall perpendicular to the openings. Besides, a heat source can be added, i.e. a heated plate. Surface temperatures and wall fluxes will be measured in addition to the air temperature at some points on a grid in the room. The same grid points can be used to measure the air velocity. Moreover, temperature sensors will be installed in between the concrete floor panels at different locations. There has been some delay regarding the construction of the test setup. However a test protocol has been developed and will be refined further in the following months. The experimental setup should be operational by November. WP3.1.3 Numerical prediction of ventilation and local heating through solar irradiation inside buildings A measurement box (Figure 37) was built. The box was equipped with 32 thermocouples. In a first instance Cu-Co thermocouples with a diameter of 0.4 mm were proposed. However, a numerical analysis showed that these thermocouples cause a too large measurement error when installing them in a field with a high temperature gradient, as in case of the box. Therefore finally very thin (diameter 0.1 mm) thermocouples were used. The thermal conductivity of the materials used (wood based MDF panel and extruded polystyrene) was measured at the laboratory (K.U.Leuven) for different temperature ranges. This measurement was carried out as well in a transient way (changing the temperatures at both sides of the samples). From the measurements and a transient simulation (Figure 37), the material’s specific heat could be derived. A transient and steady state measurement on the box was done in the laboratory (in absence of sun) using an isothermal electrical heater (Figure 37, small white box). This allows a validation of VOLTRA without the solar processor. There is a good correspondence between measured and simulated temperatures. The largest differences are due to the air temperature gradient that is not simulated by VOLTRA (assuming an isothermal air temperature). It can be expected that the air temperature gradient will be much smaller in the experiment with solar radiation as most solar radiation will strike the box floor. The transient measurement with the box in the field (Figure 37) is running since the 5th August 2008. Up to the 20th of August no appropriate external climate conditions (clear sky, wind still conditions) occurred.

Figure 36: Measurement box.


36

Figure 37: Transient simulations of measurement box.

WP3.1.4 Validation of the numerical methods with data measured in projects realised by the industrial partners Daidalos started in the beginning of July 2008 a measurement campaign in the UnilinQuickstep building. That data will be used for the validation of the numerical methods for the prediction and optimization of the summer comfort. Daidalos is measuring the outdoor climate and the indoor climate in a landscape office and in a small office for two persons. The landscape office is oriented to the north, the small to the south. First a very short description of the Unilin Building is given and then an overview follows of the measurement data. Unilin building The Unilin building in Wielsbeke is an office building with natural night ventilation and cooled ceilings. Half of the ceiling is covered with cooled ceiling panels, the other half is covered with acoustic absorption panels on the ‘strekmetaal’ of the open ceiling.

Figure 38: Facades of the Unilin Building. IWT SBO project 050154 – Heat, air and moisture performance engineering - A whole building approach Tweede jaarlijks rapport

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2

1

Figure 39: Plan of the second floor: 1 gives the position of the measurement instruments in the landscape office, 2 of the individual office.

Figure 40: Open ceiling with ‘strekmetaal’ (opening 75%).

Measurement data The measurement campaign started the third of July 2008 and measurements will be carried out for the whole summer period until the end of September. Some problems were encountered with the outdoor climate measurements; other weather data for that period will be used. The list below gives an overview of the different measurement data and the measurement instruments. Table 4: Measured data and instruments.

Parameter Outdoor climate (on the roof) Air temperature Relative humidity Wind velocity Wind direction Solar radiation

Unit

Measurement instrument

K % m/s °C W/m²

Vaisala HMP 45 A Vaisala HMP 45 A Young wind monitor 05103 Young wind monitor 05103 Pyranometer CM 3 KIPP

Landscape office IWT SBO project 050154 – Heat, air and moisture performance engineering - A whole building approach Tweede jaarlijks rapport

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Air temperature Relative humidity Supply air temperature Flux ceiling Temperature ceiling

°C % °C W/m² °C

Vaisala HMP 45 A Vaisala HMP 45 A thermocouple ? Daidalos thermocouple Pt 100 Temperature plenum °C thermocouple Temperature cooled °C thermocouple ceiling Pt 100 CO2 ppm ? UGent Opening of the windows ? UGent Individual office (worden al deze gegevens gemeten? of enkele berekend?) Air temperature °C ? UGent High-res temperature °C ? UGent (high resolution?) Dew point °C ? UGent Humidity gm/m³ ? UGent Relative humidity % ? UGent Flux ceiling W/m² ? UGent CO² ppm ? UGent Opening of the windows ? UGent Acoustical absorption material (mineral wool) is placed on the ‘open’ ceiling. Where the supply air comes into the room, the absorption material is locally removed. This wasn’t the case at the supply where measurements were going on, but we have removed it the 8th of august.

Deliverables WP3.1.1 • Paper on sensitivity of thermal performance to convective heat transfer at internal building surfaces • Report on literature review of diffuser modelling in CFD • Report on sensitivity of CHTC to diffuser modelling in CFD • Report on feasibility of the PASLINK cell WP3.1.2 • The test protocol for the PASLINK cells has been defined. WP3.1.3 • Measuring equipment was developed and built to validate the 3D solar processor. WP3.1.4 • First data of the measurement campaign regarding Unilin-Quickstep is available.

Planning WP3.1.1 • Sensitivity analysis of thermal predictions to solar irradiation at internal building surfaces using different convection algorithms. • The applicability of correlations for a range of flow regimes will be studied. In this research, the case E.2 of IEA Annex 20-project is again simulated using CFD. For a given Reynolds number, results are obtained in the range of Richardson number as IWT SBO project 050154 – Heat, air and moisture performance engineering - A whole building approach Tweede jaarlijks rapport

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0<=Ri<=10 and a fixed Prandtl number of 0.71. Correlations, extracted from literature, are compared with the predicted CHTC values. • Based on the experiments in the PASLINK cells available at BBRI, studying the interaction between solar gains, thermal storage and ventilation, the CFD-simulations will be validated in order to derive new correlations. WP3.1.2 • During the winter of 2008-2009 steady-state experiments will be carried out in order to validate the CFD simulations of 3.1.1. Dynamic experiments will be performed in summer 2009: with and without thermal mass, with and without the outside box. WP3.1.3 • A measurement campaign is started to provide validation data for the 3D solar processor. The 3D solar processor will be validated with experimental data and if necessary, adjustments will be made to the software. WP3.1.4 • Measurement campaigns will be continued. Analysis of the results will follow during the coming work year.


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WP3.2 Development of CFD-HAM model Objectives In WP3.2, the emphasis goes to a correct and reliable implementation of moisture transport in CFD-calculations. The enrichment of classical CFD to a CFD-HAM model and the formulation of efficient solution strategies by the build in of UDF’s (User Defined Functions) necessitates an in depth study. WP3.2.1 In order to validate the CFD-HAM model, laboratory tests will be performed in a climate chamber where a conditioned air jet enters at the opposite site of a test sample. The flow pattern inside the climate chamber will be measured with a two-dimensional hotwire anemometer. Velocities near the wall and test sample are again measured with the hotwire anemometer. Temperature and relative humidity inside and around the test sample are also measured. This information is used to determine the convective transfer coefficients. The experiments consist in the moistening (drying) of samples by moist (dry) air. WP3.2.2 A HAM-model will be developed in the CFD-environment. Current state of the art CFD does not offer the possibility to describe the interaction between fluid and solid material for complex geometries in an efficient and satisfying manner. In these cases, the boundary layer problem can only be solved using very fine grids leading to unreasonably high calculation times. Therefore in this project adequate models using UDF’s will be developed and implemented in CFD: i.e. in the boundary cells (empirical) relations for the convective coefficients are built in. WP3.2.3 Validation of the numerical methods with data measured in projects realised by the industrial partners

Description of work WP3.2.1 Laboratory test for the validation of the CFD-HAM model The surface transfer coefficient for mass transfer is usually unknown in building simulation models. The standard procedure is using the analogy between heat and mass transport to calculate this coefficient. However, this analogy does not always apply. In WP 3.2.2, a coupled CFD-HAM model is developed which can be used to simulate both the surface transfer coefficient for heat transfer as for mass transfer. However these new models require validation. Therefore there is a need for an experimental setup which can be used to study mass transfer coefficients and can provide experimental data for the validation of newly developed models. The experimental setup consists of two parts. The climate chamber with inner and outer room is shown on the left hand side of Figure 41. On the right hand side the climate control group is shown. Air is drawn from the inner chamber by a recirculation fan and flows through a cooling coil (1-2) where it is cooled and dehumidified. The cooled air flows through a second heat exchanger where it is reheated (2-3). Finally the air is humidified again by adding steam coming from a specially designed steam humidifier and enters the room a predetermined conditions (3-4).


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Figure 41: Schematic representation of the test facility.

Temperature and relative humidity of the jet entering the room are closely controlled. Controlling the temperature is fairly easy by using a resistive heater controlled by a PID controller. In order to control the relative humidity two control strategies are possible: Controlling temperature and relative humidity − Advantage: cheap sensors and relative fast response − Disadvantage: relative humidity is dependent on the temperature which makes it hard to control when temperature changes occur. Controlling temperature and humidity ratio (a measure for the absolute humidity) − Advantage: not dependent on temperature − Disadvantage: expensive sensors, slow response. In order to avoid the expensive dewpoint sensors, capacitive RH sensors are used to measure the relative humidity together with the temperature. From this, the humidity ratio can easily be calculated. However, some problems occurred with these sensors when fast temperature changes where imposed. A test wall is built inside the climate chamber. In this wall, a sample of calcium silicate of 200 mm by 200 mm is placed. The conditioned air jet hits the test sample. The relative humidity of the jet follows a predetermined profile where several hours of high relative humidity are followed by several hours of low relative humidity. Relative humidity sensors and thermocouples are placed inside the material at various depths in order to measure the moisture penetration inside the materials. A hotwire anemometer, connected to a robot arm, is placed inside the chamber and is able to measure the velocity field inside the room. The velocity field was measured several times with little variation between the measurements so the jet can be considered to be stable (Figure 49). These measurements can then be used to validate CFD simulations of the velocity field in the room. The inlet profile is measured with the same hotwire (Figure 48). These measurements can then be used as boundary condition for CFD simulations.


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WP3.2.2 Development of a CFD-HAM-model In a previous year report the development and integration of an isothermal HAM model into a commercial CFD code was described. For practical applications like damage prediction it is however necessary that the HAM model can also simulate non-isothermal situations. Last year the isothermal HAM model was further developed into a non-isothermal model. The newly developed non-isothermal HAM model was elaborately validated using forced convection benchmark experiments. These benchmark experiments were performed within the frame of the IEA Annex 41 ‘Whole Building Heat, Air, Moisture response’. The benchmark experiments proved the validity and accuracy of the new model for temperature as well as relative humidity predictions. Figure 50 and Figure 51 give an example of the agreement between measurement and simulation for one benchmark test. It should be noted that the benchmark validation tests were small-scale material tests and validation on a room level remains necessary.


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To further enhance the accuracy of the non-isothermal HAM model a hysteresis model was added. This hysteresis model accounts for the dynamic behaviour of the moisture storage and release in the porous material. The inclusion of hysteresis effects in the model is very important when the behaviour of materials like wood has to be simulated. Validation of the HAM model combined with the hysteresis model showed the increased accuracy of the simulations and proved the validity of the implemented hysteresis model. WP3.2.3 Validation of the numerical methods with data measured in projects realised by the industrial partners The role of this industrial partner was further defined during the first part of this second work year. Some practical experimentation cases, related to the interior conditions of buildings (temperature, humidity, tightness), were defined for further study and measurement. Specific real building projects that are focused for the measurements are: IDEWE – Roeselare: low energy building The building is in use since 2007. 2 measurement campaigns, one in the winter of 2007-2008 and one in the summer of 2008 were set up. The measured parameters were: o Outside temperature at air intake o Inside temperature after earth-to-air heat exchanger o Inside temperature of air after heat recuperation o Inside temperature in 3 locations inside the building. Bourgoyen – Gent : passive office project with high air tightness The implementation of this project, where Ingenieursbureau Stockman NV was designer of the technical installation, reached its completion during the spring of 2008. A measurement campaign was set up during the summer of 2008 (which will be completed at the beginning of September). The results of the measurement campaigns will be: • Conclusion on the efficiency of earth-to-air heat exchangers. • Input of measurement data for the validation of the theoretical models. First conclusions of the study show a good efficiency of the IDEWE earth-to-air heat exchanger in winter conditions (heating capacity of the soil). The efficiency in summer conditions is still to be analysed. In the margin, a selection tool for earth-to-air heat exchangers was made. IWT SBO project 050154 – Heat, air and moisture performance engineering - A whole building approach Tweede jaarlijks rapport

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Deliverables WP3.2.1 • A test facility was built is now operational. • First measurements are done to check the controllability of the inlet temperature and relative humidity. • The velocity field inside the room is measured with a hotwire anemometer. • The inlet profile is measured. WP3.2.2 • The isothermal HAM model was further developed into a non-isothermal model. • The model is validated with small-scale material tests. WP3.2.3 • First data of the measurement campaign regarding IDWE is available.

Planning WP3.2.1 • A measurement campaign will be started. The resulting experimental data can be used for benchmarking new HAM models. • A measurement campaign to study the effect of moisture buffering will be started. For this campaign the test facility needs to be altered. • A measurement campaign to study mass transfer coefficients will be started. For this campaign a load cell has to be implemented. WP3.2.2 • Validation of the model on room level. WP3.2.3 • Measurement campaigns will be continued. The analysis of the measurement data on inside conditions will be analysed further during the coming work year. Additional measurement campaigns as input to the model validation are also planned.


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WP4 Towards an integrated approach Objectives The main objective of WP4 is the generation of a prototype software environment that will enable an integral approach of all relevant heat, air and moisture transfer processes of a building. This prototype environment will be based on externally run-time coupled distribution applications, i.e. different software packages will run in parallel and exchange simulation results at appropriate time intervals throughout the simulation period. The goal of WP4 is twofold: (1) to use the prototype for increasing our knowledge regarding the modelling and simulation aspects; (2) to use the prototype for solving real-world building related HAM-problems in order to demonstrate the practical application and benefits of this approach. The work package consists of 3 subtasks: WP4.1 The development of a prototype software environment is envisaged. ESP-r is used as starting point to develop an integrated system comprising run-time coupled distributed applications. Existing models and models developed in WP1-3 will be coupled to ESP-r, for which already some preliminary external coupling features have been developed. ESP-r itself will act as overall controller and integrator. WP4.2 The development of a coupling necessity decision procedure (CNDP). An important prerequisite for this is an investigation identifying for which practical cases and circumstances which level of integrated software is needed. In addition, guidelines for selection of the proper spatial and temporal resolutions have to be provided. WP4.3 Validation and verification. Validation and verification will be conducted to validate the developed integrated model and the coupling procedure assessment method.

Description of work Prototype 1 for the run-time coupling of ESP-r and the commercially available CFD code Fluent was the object of multiple improvements and tests. • Implementation improvement, fixing several small bugs, hardcoded parts and development of an interface for the coupling. The present implementation is more stable and runs faster, enabling better integration with WP3 in the next phase of the project. • Validation of natural convection flow using model intercomparison. The result of the prototype was compared with a stand-alone CFD simulation of the conjugated heat transfer in the solid and fluid domain. The schematic representation of the model intercomparison is shown in Figure 52. The response of the BES-CFD model and of the conjugate heat transfer model to a 20 °C step change in surface temperature were compared to each other.


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Figure 52: Model intercomparison procedure.

Figure 53 shows the computational grid for the CFD stand-alone simulation, which was obtained based on grid sensitivity analysis, including solid and fluid domain.

Figure 53: 3D computational grid for the CFD stand-alone model.

In the BES-CFD coupling, BES is solving the heat conduction equation in the solid domain while CFD is solving the flow equations for the fluid domain. Figure 54 shows the model in the BES-CFD prototype. The average cavity temperature from the BES-CFD coupling is compared with that of CFD stand-alone and BES stand-alone in Figure 55. During the first hour of simulation, the average temperatures are in good agreement. At the end of the fist hour, CFD is switched off and BES is used to predict the average temperature. In BES-stand-alone, the empirical equation for internal CHTC (Alamdari and Hammond, 1982) is applied. As can be observed from Figure 55, there is a 1°C difference between the results for this simple geometry when using the empirical correlation.


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Extension of the coupling user guide which was tested and reviewed by the other members of the group. Cooperation with WP3 for simulation of Unilin building as the second case study.

Cooperation with WP3 was started by a meeting at Ghent University to arrange the details of the realistic case study of the Unilin building (Figure 56a), which is currently in progress. Intensive communication between WP3 and WP4 is maintained to define the features of this case study. Using Prototype 1, a realistic case study was produced. A single zone of the Unilin building, a low-rise office building in Flanders, was modelled in ESP-r and Fluent to study thermal comfort problems. The integration with the HVAC system was simulated as well. The use of Prototype 1 to simulate natural ventilation problems was studied, focusing on IWT SBO project 050154 – Heat, air and moisture performance engineering - A whole building approach Tweede jaarlijks rapport

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the definition of the inlet velocity profile for large inlet openings (Figure 57). The main variables influencing the velocity profile were identified through literature review and 2D CFD simulations. The coupling was performed for one of the individual offices indicated in Figure 56b. Figure 58 shows the contours of temperature at 12:00 for a cross section of the office.

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Figure 56: (a) South west view of Unilin building. (b) Model of the whole second floor of the Unilin building in ESP-r.

Figure 57: Computational grid for the coupled BES-CFD prototype.


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Figure 58: Contours of temperature for a cross section.

PPD values for the occupancy period using the results of the coupling for a specific coordinate in the office (near the south west window) are plotted in Figure 59.

Figure 59: PPD value predicted for the occupancy period.

• Development of prototype 2 Prototype 2 has been partially developed for the decoupled solution of exterior domain with the building envelope. Concerning this prototype, cooperation with WP1 has been initiated to define a common protocol for models and information exchange between ESP-r and FLUENT. • Development of prototype 3 The development of Prototype 3 for the run-time coupling of ESP-r and HAMFEM is in progress. Concerning HAMFEM, the work was focused on: o Reproduction of benchmark cases using HAMFEM to assure the quality of the prototype under development o Improvement of HAMFEM user guide o Definition of the coupling variables o Compilation on Unix-Solaris system o Testing simplified programs using Sockets to perform the inter-process communication between FORTRAN and C programs, in run-time in a multiplatform environment. Concerning ESP-r the work was focused on: IWT SBO project 050154 – Heat, air and moisture performance engineering - A whole building approach Tweede jaarlijks rapport

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o Literature review on the matrix formation and solution in ESP-r code o Definition of the coupling variables o Solution of the domain overlap problem Much effort has been devoted to the development of the Coupling Necessity Decision Procedure (CNDP) in the past year. The work has focused on the identification of the state of the art models in Building Performance Simulation (BPS) programs considering the physical processes addressed in the present project, identifying their capabilities and deficiencies. The main activities were: • Overview of pressure coefficient (Cp) data in BPS An extensive overview of CP data sources for external convective heat transfer coefficients (CHTCEXT) was performed. Figure 60 indicates the variation observed in the CP predictions using different data sources, which ideally should all give the same result.

Figure 60: Variation in CP predictions by different data source.

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Overview of external convective heat transfer models in BPS

Figure 61 shows the variation of CHTCEXT predicted using different empirical correlations for a windward surface. Vf is the wind speed measured at a weather station. The impact of this variation on annual heating and cooling demand can be seen in Figure 62.


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Figure 61: Prediction of CHTCEXT by different empirical correlation. U =20.4 W/m 2K

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Figure 62: Impact of different CHTCEXT on the annual heating and cooling demand.

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Uncertainty on the use of surface averaged pressure coefficient for air flow studies

The uncertainty related to the use of surface averaged CP, for the case of a cubic building with two openings was investigated. A method was developed to calculate the uncertainty. It is based on comparison of the flow rate calculated using the averaged values (φAV) and that calculated using local values (φLOC). The study considers a large number of combinations for the positions of the ventilation openings in the facade. For each pair of openings (i), the values of φLOC_i and φAV_i are calculated. Based on the ratio between φLOC_i and φAV_i the relative error (ri) is calculated. The relative error is presented statistically, providing


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Uncertainty analysis is a key step in the CNDP definition, and some exploratory work was developed in this field: • Literature review • Model uncertainties versus model errors • Sampling techniques • Monte Carlo technique • Uncertainty analysis using ESP-r Figure 65 outlines the structure of the CNDP. CNDP indicates the use of successive increments in the modelling level and in each step the uncertainty is compared to target value, such as maximum or minimum allowed values. This process is repeated until the uncertainty IWT SBO project 050154 – Heat, air and moisture performance engineering - A whole building approach Tweede jaarlijks rapport

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in the results does not compromise the judgement of the designer. When this level is achieved, the model is accepted and no further refinements are necessary. Building PI Target value Physical process

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Figure 65: Structure of coupling necessity decision procedure.

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Software development o Prototype 1. Improved version and user guide. o HAMFEM version for Unix-Solaris o IPC software using Sockets Presentations o Monthly public PhD presentations are organised at the home university (TU Eindhoven) to provide information concerning the WP4 activities to the academic and industrial community. o Presentations on the Regional Netherlands + Flanders Meeting of the International Building Performance Simulation Association - (June 2008) at the TU Eindhoven. o Presentations on the Building Physics PhD Symposium at Czech Technical University in Prague (may 2008)

Planning Software development • Prototype 1 (ESP-r + Fluent) integration with WP3 • Prototype 1 integration with HVAC and AFN in air based systems • Prototype 3 (ESP-r + HAMFEM) conclusion and validation Validation and case studies • Extensive collaboration with WP1 for validation purposes using the BBRI “WINDHouse” • The Unilin building as the case study for further studies using the coupled prototypes CNDP • CNDP version for pressure coefficient • CNDP version for convection at the external facade. • Integration of data from WP1 using Prototype 2 (ESP-r stand-alone) Journal papers • Validation of BES-CFD coupling by model intercomparison IWT SBO project 050154 – Heat, air and moisture performance engineering - A whole building approach Tweede jaarlijks rapport

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Coupling BES and HAM programs Validation of BES-HAM coupling by model intercomparison Uncertainty on the use of surface averaged pressure coefficient for air flow studies Modelling uncertainty in BPS


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WP5.1 Strategic and integrated planning of research activities Objectives The main objective of this subtask is the strategic and integrated planning of research activities. Within the scope of the Intelligence Network, it is foreseen to set up a committee which will have as duties: (1) to identify priority themes for basic research, applied research and dissemination activities; (2) to set up strategic planning meetings with representatives of leading Flemish industries and/or industrial associations to identify the priorities for future research; (3) to evaluate the progress and outcome of research projects and to plan the required dissemination strategies; (4) to set up a electronic project centre for use by the network members and related organisations.

Description of work Structured collaboration During this first year, there were several formal and informal discussions about the possibilities for a structured collaboration between the present partners and on longer terms with other partners. On the short and medium term, it was agreed to start up a more structured collaboration without a specific legal structure (e.g. legal status of non-profit association) in order to promote common activities. If practice proves that there is a need for, one might consider in a later phase a more formal collaboration. One of the challenges for a structured collaboration is the achievement of an intelligent balance between collaboration and competition. In certain cases, potential customers have the choice between one of the network partners without the need to involve them all. Moreover, some studies have a confidential nature. The following proposals/collaborations were discussed between several partners: • Project on ‘after-insulation’: proposal submitted by UGent and BBRI. This proposal was submitted during the first year. It was approved and is running. • Assessment of innovative systems in the EPB context : active collaboration between BBRI, UGent en K.U.Leuven This collaboration started up in the first year and is continuing. The formal framework for the assessment of such systems is now done within the framework of the BUTGB (Belgian Union for technical approval in construction). • IWT Project on thermal bridges (already started before start of the SBO project): active collaboration between Sint Lucas, UGent, K.U.Leuven, Physibel and BBRI. This collaboration has continued during the 2nd year and even widened. In July 2008, a proposal involving BBRI, UGent, KUL, Sint Lucas, UCL and ULG has been submitted to the 3 regions for support and was approved. The project starts in September. Brainstorming on projects and programs As was announced in the report of the first year, the network has the ambition to play in the future a role in the following areas: • Brainstorming on possible common proposals in the framework of project calls. In the framework of project calls (IWT, EC, …), it might be efficient to have brainstorming


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meetings whereby possible projects with common participation are discussed. This can take different forms, e.g.: o Substantial involvement of several partners in the proposal (with other partners if needed); o Proposals whereby only 1 or 2 partners are heavily involved but whereby other partners have a supportive role (e.g. as part of advisory group or dissemination partner) • Brainstorming on priorities. Another area of brainstorming is more pro-active, whereby suggestions are formulated for future priorities, project calls. Due to staffing problems was the activity level lower than expected. Communication and dissemination In order to facilitate communication between the partners and with the external building community, a first website has been set up by K.U.Leuven (www.kuleuven.be/bwf - click on right hand side on ‘SBO project’). For private part of website, the user name and password can be obtained from K.U.Leuven. Training as a mean of disseminating the results of the structured collaboration Workshops • CFD is becoming increasingly operational for use in daily practice. On September 20 2007; and in on order to show the potential of CFD, a workshop was organised in the framework of the SBO project. • On September 4 2008 a 2nd workshop is organised around the topic of ‘heat, air and moisture management in historic buildings’. Post-graduate course An advanced course on heat, air and moisture transfer in buildings is planned. As indicated in the proposal, there is the idea of a higher course ‘Heat, air and moisture transfer: an integrated approach’. This course will be organised in collaboration with several organisations, including the Technical Institute of the KVIV, the Dutch-Flemish Buildings Physics Association, IBPSA (International Buildings Performance Simulation Association, ATIC, TVVL, …. The aim is a course at the level of the existing course on acoustics (‘hogere cursus akoestiek’), and to have it organised on a regular base. During the 2nd year, discussions continued about the content of the course and about the aims in order not to interfere with existing initiatives such as the International Building Physics Summer Course (K.U.Leuven, UGent and TU/e) and other KVIV courses) and to define the target groups. Webex internet sessions It is the intention to set up before the end of 2008 the first internet sessions by using webex. The topics will cover more practice oriented issues as well as more academic topics.

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A TETRA-project ‘Naïsolatie’ is obtained and several partners are involved in the structure for assessment of innovative systems in the EPB context. The workshop on historic buildings is another deliverable of this WP.


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Further attention will be paid to inscribe the collaboration between all partners in future research projects and about the structuring the collaboration practically in order to deal with demands of industry. Contacts with a research board of major industrial partners will be established. If research activities fit in project calls, the consortium of partners will apply. The information on the website will be extended and transferred to BBRI. Once a critical amount of content is reached, the website will be given a much more public status than a mean of internal communication. The higher course will be implemented practically and the aim is to give a series of seminars, in collaboration with other partners and coordinating organisations in order to disseminate the project results to all actors on the Flemish building market involved.


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WP5.2 Strategic implementation of testing and simulation facilities Objectives The main objective of this subtask is the strategic implementation of testing and simulation facilities. The proposed consortium has already a wide range of testing and simulation facilities. It is envisaged to make an in depth review and evaluation of these facilities in order to streamline and rationalise the future development of the facilities.

Description of work In a first phase all partners have been demanded to make up a list of the testing facilities of which they dispose. The collection of information on software tools has started up. It is the intention to have a specific filter on the software tools database as developed by DOE (http://www.eere.energy.gov/buildings/tools_directory/subjects_sub.cfm ). The role of high quality laboratory infrastructure is of key importance for progress in basic research. The listing of the testing and simulation facilities is a useful tool for each partner to define his needs for missing infrastructure and to come to a priority list for investments in missing infrastructure. Based on the list of measurement utilities and the need for measurement utilities, the missing links useful for all partners can be defined. Due to staffing problems, this task did not progress as much as planned.

Deliverables No deliverables have been obtained yet.

Planning Due to a break of the BBRI person implied, the work is going to restart with an update of the listings above.


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References Alamdari F., Hammond G. P. (1982), Improved data correlations for buoyancy-driven convection in rooms, Building Services Engineering Research and Technology 4(3) 106-112. Breesch H. (2006), Natural night ventilation in office buildings – Performance evaluation based on simulation, uncertainty and sensitivity analysis, PhD Thesis, Ghent University, Ghent, Belgium. Cuerva A., Sanz-Andres A. (2000), On sonic anemometer measurement theory, Journal of Wind Engineering and Industrial Aerodynamics 88(1) 25-55. Cuerva A., Sanz-Andres A., Franchini S., Eecen P., Busche P., Pedersen T.F. and Mouzakis F. (2006), Accurate wind measurements in wind energy (ACCUWIND) - Task 2. Improve the Accuracy of Sonic Anemometers - Final Report., IDR/UPM, Madrid. Gill Instruments (2007), WindMaster and WindMaster Pro - User Manual, Gill Llt. Goethals K., Janssens A. (2007), Feasibility study of the PASLINK cell, Internal report SBO project IWT-050154. Goethals K., Janssens A. (2008a), Sensitivity analysis of thermal predictions to convective heat transfer at internal building surfaces, submitted to the Building Physics Symposium, Leuven, Belgium. Goethals K., Janssens A. (2008b), Literature review of diffuser modelling in computational fluid dynamics, Internal report SBO project IWT-050154. Goethals K., Janssens A. (2008c), Sensitivity analysis of predicted convective heat transfer at internal building surfaces to diffuser modelling in computational fluid dynamics, Internal report SBO project IWT-050154. Lemaire A.D. (1993), Annex 20 – Air flow patterns within building. Room air and contaminant flow – Evaluation of computational methods, TNO Building and Construction Research, Delft, the Netherlands. Parmentier B. (2002), Full-scale wind pressures on a permeable roof of a low-rise building, 5th UK Conference on Wind Engineering, Nottingham, September 4th-6th. Sacré S., Janssens A., De Paepe M. (2007), Literature review of most used empirical convective heat transfer coefficients correlations in building design, Internal report SBO project IWT-050154. Srebric J. and Chen Q. (2002), Simplified numerical models for complex air supply diffusers, HVAC&R Research, 8(3), pp.277-294. Sturgeon M.C. (2005), Wind tunnel tests of some low-cost sonic anemometers, WMO Technical Conference on Meteorological and Environmental Instruments and Methods of Observation (TECO2005), Bucharest, 4-7 May 2005. Wauben W.M.F. (2005), Wind tunnel and field test of three 2D sonic anemometers, KNMI


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1.2 Bijsturingen in het project Onderzoeksinhoud Er zijn tijdens het tweede projectjaar enkele bijsturingen van het project nodig gebleken wat betreft onderzoeksinhoud: • In WP1.1 zullen ook de metingen op het VRT gebouw door Daidalos dienen om betrouwbare data te voorzien voor simulaties. Deze case wordt mee in het werkpakket genomen omdat het een realistische situatie is waarop de ontwikkelde numerieke modellen kunnen getest worden. • In WP2 zal het WINDHouse niet gebruikt worden voor de experimentele analyse. In plaats daarvan is het VLIET gebouw uitgerust met de nodige meetapparatuur. • In WP 3.1.1 zal naast de experimentele analyse ook een numerieke analyse (CFD) volgen, wat oorspronkelijk niet gepland was. • Wegens praktische redenen is beslist om het IDEE gebouw niet te gebruiken voor de experimentele analyse in WP 3.1.2. In plaats daarvan zullen de PASLINK cellen gebruikt worden. • In WP4 zullen ook het Unilin gebouw en het WINDHouse van het WTCB in de analyse worden opgenomen alhoewel dit oorspronkelijk niet voorzien was.

Onderzoeksbegeleiding Er zijn tijdens het tweede projectjaar geen bijsturingen van het project nodig gebleken wat betreft onderzoeksbegeleiding.

1.3 Beheer van het project Het beheer van het project bestaat uit verschillende componenten. Vooreerst is er het algemene projectbeheer dat de strategische en structurele aspecten van het project behelst. Het wetenschappelijke beheer betreft de organisatie, opvolging en evaluatie van het onderzoekswerk in de deelnemende onderzoeksgroepen en hun onderlinge communicatie. Tot slot moet ook de interactie met de gebruikersgroep beheerd worden. De ontwikkelde website is voor deze componenten een belangrijk instrument.

Algemeen projectbeheer Bij het project zijn 9 partners betrokken, waarvan 3 industriële partners: • Katholieke Universiteit Leuven, Laboratorium Bouwfysica: Staf Roels (KUL) • Universiteit Gent, vakgroep Mechanica van Stroming, Warmte en Verbranding: Erik Dick (UG-FHC), Michel De Paepe ((UG-FHC) • Universiteit Gent, vakgroep Architectuur en Stedenbouw: Arnold Janssens (UG-AS) • Technische Universiteit Eindhoven, Unit Building Physics & Systems: Jan Hensen (TU/e) • Wetenschappelijk en Technisch Centrum voor het Bouwbedrijf, departement Geotechniek en Structuren: Benoit Parmentier (WTCB-GS) • Wetenschappelijk en Technisch Centrum voor het Bouwbedrijf, departement Bouwfysica en Uitrustingen: Peter Wouters (WTCB-BU) • Daidalos Bouwfysisch Ingenieursbureau: Filip Descamps (DAI) • Physibel: Piet Houthuys (PHYS) • Ingenieursbureau Stockman: Piet Delagaye (STO)


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Tussen deze negen partners werd bij het begin van het eerste projectjaar een consortium overeenkomst afgesloten, welke de contractuele aangelegenheden van de samenwerking bevestigt. Deze betreffen de achtergrondkennis van de partners, de reeds bestaande software ontwikkeld door de partners en de bescherming van de projectresultaten. Het Project Coordination Commitee (PCC) wordt gevormd door Peter Wouters(WTCB-BU), Benoit Parmentier (WTCB-GS), Piet Delagaye (STO), Jan Hensen (TU/e), Michel De Paepe (UG-FHC), Arnold Janssens (UG-AS), Filip Descamps (DAI), Piet Houthuys (PHYS), Hugo Hens (KUL) en Staf Roels (KUL), dat instaat voor het algemene beheer van het project.

Wetenschappelijk projectbeheer Binnen iedere deelnemende onderzoeksgroep neemt de werkpakketleider het dagelijkse projectbeheer op zich. Hij evalueert de wetenschappelijke vooruitgang van de onderzoekers van de onderzoeksgroep en rapporteert halfjaarlijks dienaangaande aan het PCC. Het wetenschappelijk beheer beoogt verder een goede samenwerking en uitwisseling tussen de verschillende onderzoekers. De onderzoeksresultaten en -plannen worden steeds gepresenteerd op de halfjaarlijkse vergaderingen met de stuurgroep. Daarenboven zijn er afgelopen jaar verschillende contactenmomenten geweest tussen de onderzoekers.

Gebruikersgroep projectbeheer Zie 2.2 Overzicht van de uitgevoerde valorisatieacties, oprichting en vergaderingen gebruikersgroep.

1.4 Haalbaarheid van het project Het project verloopt goed, zowel voor onderzoek als valorisatie. Niettemin zijn er enkele deelpakketten die wat achterstand hebben opgelopen inzake onderzoek in het voorbije projectjaar: • WP 1.1.1: Er is enige achterstand inzake de geplande experimenten ten gevolge van een personeelstekort aan het WTCB. Volgend projectjaar zal een werknemer van het WTCB zich met dit deelpakket bezighouden om zo de nodige data tijdig te kunnen voorzien voor de numerieke simulaties van WP1.1.2. • WP2.1: Ten gevolge van een personeelswissel (Joachim Verhaegen heeft het project verlaten (11/11/07) en is vervangen door Tadiwos Zerihun Desta (15/04/08)) is er enige achterstand inzake de numerieke modellering maar deze kan ingehaald worden. • WP3.1.1: De set-up van de PASLINK-testen is verder uitgewerkt. Een finale check is noodzakelijk om te bevestigen dat de resultaten zullen voldoen aan de eisen voor validatie. Wegens personeelveranderingen werden de PASLINK-testen nog niet gestart gedurende het tweede jaar. Het opstarten van de testen is voorzien in het begin van het derde jaar. • WP5: Door een personeelstekort aan het WTCB is er weinig gebeurd inzake dit werkpakket. Het komende projectjaar zal dit echter gecompenseerd worden wat geen probleem vormt gezien het geringe aantal manmaanden dat hiervoor voorzien is. De overige deelpakketen zijn op schema of liggen voor op schema. Alle zeven de onderzoeksfuncties zijn ingevuld op dit moment. De haalbaarheid van het project wordt niet in vraag gesteld. Zie 2.2 Overzicht van de uitgevoerde valoriatieacties voor een overzicht van de reeds ondernomen valorisatiereacties


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1.5 Te beschermen resultaten De uit dit projectjaar resulterende software wordt nog niet publiekelijk verspreid wat bescherming nog niet noodzakelijk maakt.


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2 Utilisatieverslag 2.1 Valorisatiepotentieel: geactualiseerde visie Toepassingsgebieden Dit project heeft als doel het verenigen van verschillende onderzoeksdomeinen om zo te komen tot een geïntegreerde benadering van warmte-, lucht-, en massatransport in gebouwen. Deze benadering dient in eerste instantie om kennis te verzamelen omtrent het koppelen van verschillende numerieke modellen in een geïntegreerd model. Deze integrale benadering moet leiden tot een optimalisatie van gebouwen, zowel wat betreft economische besparingen als duurzame ontwikkeling. Dit maakt dat het project verscheidene toepassingsgebieden heeft: • Bij het ontwerp en de constructie van nieuwe hoogtechnologische gebouwen proberen de ontwerpers de gebouwrespons inzake warmte-, lucht- en vochtgedrag te voorspellen en te regelen. Hierbij kan de door het project ontwikkelde kennis bijdragen tot een inzicht in de interactie tussen onder andere HVAC systemen en de gebouwschil. Dit kan leiden tot de optimalisatie van HVAC controlesystemen. • Om kleine gebouwen duurzaam en energiezuinig te maken, worden er verschillende innovatieve systemen ontwikkeld, zoals gevels met stalen of houten frames waartussen hygroscopisch bufferende materialen worden geplaatst met dampopen binnen- en buitenbekleding. Een geïntegreerde aanpak laat een gedetailleerde analyse van de duurzaamheid van deze systemen toe. • De geïntegreerde aanpak kan ook van nut zijn bij de renovatie en restauratie van het Vlaams cultureel erfgoed. Aangezien er hierbij meestal ingrijpende veranderingen worden doorgevoerd, is een goede evaluatie van de respons van het gebouw op deze nieuwe situatie van belang. Daarnaast kan de methodologie ook leiden tot een geoptimaliseerde strategie voor de bescherming van cultureel erfgoed (musea, monumentale orgels, schilderijen, …). • De geïntegreerde aanpak kan meer inzicht bieden in de invloed van de buitencondities op de luchtstroming binnen voor de analyse van natuurlijke ventilatiestrategieën. Ook voor koeling d.m.v. nachtventilatie kan dit nuttig zijn. Uiteraard kan dit project ook van nut zijn in andere toepassingsgebieden, waarvan er enkele aangehaald worden verderop in de tekst.

Valorisatie- en absorptiepotentieel Dit project heeft als doel de ontwikkeling van een geïntegreerd model wat moet toelaten om het hygrothermisch gedrag van gebouwen gedetailleerd te evalueren. Er zullen verscheidene programma’s gebruikt worden op verschillende niveaus en, afhankelijk van de toepassing, al dan niet gekoppeld. De belangrijkste zijn CFD, gebouwenergiesimulatieprogramma’s en gekoppelde warmte-, lucht- en vochttransportmodellen. Op lange termijn wordt de commerciele ontwikkeling van een geïntegreerd model beoogd. Omwille van de complexiteit van de programma’s is het wat ambitieus om deze ontwikkeling op korte termijn te zien. Deze ontwikkelingen zullen later dus vooral tot nut zijn voor studiebureaus en software ontwikkelaars. Op korte termijn is echter de verspreiding en toegankelijkheid van de opgebouwde kennis naar de bouwsector toe van belang. Dit laatste komt het utilisatiepotentieel zeker ten goede aangezien elke begunstigde de verworven kennis kan aanwenden om in zijn werkgebied vooruitgang te boeken. De strategie die hiervoor ontwikkeld werd, wordt in de volgende paragraaf besproken. IWT SBO project 050154 – Heat, air and moisture performance engineering - A whole building approach Tweede jaarlijks rapport

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Valorisatieplan en acties voor de verspreiding van kennis Opdat de bouwsector de ontwikkelde kennis kan aanwenden is het belangrijk dat deze kennis door de projectpartners op een duidelijke wijze wordt overdragen. Dit is één van de hoofddoelstellingen van WP5. Om het valorisatie en absorptiepotentieel van het project te vergroten werd er een gebruikersgroep opgericht. De leden van deze gebruikersgroep hebben niet alleen als functie om de kennis over te dragen. Zij worden ook verwacht om tijdens het project feedback te geven over de resultaten. De gebruikersgroep werd samengesteld uit een zo breed mogelijk publiek uit verschillende subgroepen in de bouwnijverheid: 1) de sector van productontwikkeling en de producenten van bouwmaterialen; 2) architecten en aannemers samen met professionele klanten; 3) ingenieursbureaus en gebouwbeheer (building management offices); 4) de wetenschappelijke onderzoekswereld; 5) gebruikers die zich bezighouden met duurzame ontwikkeling in de bouwnijverheid. Deze opdeling in subgroepen werd gemaakt opdat de overdracht van kennis zou kunnen gerealiseerd worden op een gepaste wijze voor elke subgroep. Door middel van aangepaste sessies voor één of verschillende subgroepen kan de verworven kennis toegankelijk gemaakt worden. Een voorbeeld hiervan is de CFD workshop (2007) aansluitend bij de tweede plenaire vergadering van de gebruikersgroep. Deze was vooral bedoeld om subgroepen 1, 3 en 4 aan te spreken. Ook de geplande workshop (Warmte-, lucht- en vochtproblematiek bij historische gebouwen) aansluitend bij de derde plenaire vergadering van de gebruikersgroep heeft als doel kennis over te dragen aan de gebruikersgroep. Deze workshop is gericht naar een breder publiek en is daardoor toegankelijk voor praktisch alle subgroepen. In het verdere verloop van het project zullen er nog zulke sessies gehouden worden die toegankelijk zijn voor meerdere subgroepen. Een ander initiatief wat moet bijdragen tot de verspreiding van de kennis van de partners is de oprichting van InfoHAM, wat zal dienen als een informatie netwerk omtrent onderzoek over warmte-, lucht- en massatransport. Daarenboven zal InfoHAM ook cursussen en lezingen organiseren, zoals reeds vermeld werd onder WP5. De goede samenwerking tussen de verschillende onderzoeksinstellingen is ook belangrijk aangezien deze zorgt voor een uitwisseling en uitbreiding van kennis en expertise in de verschillende vakgebieden. Hierbij is tevens de bijdrage van de industriële partners van groot belang.

Verdere toepassingsgebieden Aangezien dit project een integratiemethodologie zal aanreiken, kan dit in vele andere onderzoeksdomeinen ook toepassingen hebben welke evenwel niet beperkt zijn tot de bouwsector. Hieronder worden enkele mogelijke toepassingsgebieden aangehaald. Een uitgebreide beschrijving ervan kan gevonden worden in de projectaanvraag. • Optimisatie van productieprocessen voor materialen • Slagregen als een randvoorwaarde voor onderzoek in bouwfysica en aardwetenschappen • Schadeanalyse van onderdelen van het cultureel erfgoed in historische gebouwen • Optimalisatie van 3D (thermische) simulatieprogramma’s • Optimalisatie van binnenomgevingen van auto’s, vliegtuigen en treinen • Computer gestuurd ontwerp van bio-thermische processen van landbouwproducten • Optimalisatie van koeling van elektronische componenten en temperatuurmanagement van PCB’s door gebruik te maken van de VLES techniek IWT SBO project 050154 – Heat, air and moisture performance engineering - A whole building approach Tweede jaarlijks rapport

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2.2 Overzicht van de uitgevoerde valorisatieacties Dit onderdeel geeft aan welke valorisatieacties er ondernomen zijn tijdens het tweede projectjaar.

Oprichting en vergaderingen gebruikersgroep Er werd een gebruikersgroep opgericht bij de aanvraag van het project dewelke momenteel 28 leden telt: • CIR • CIR-Styfabel • Febe • IsoproC • Renson • Reynaers Aluminium • Verozo • Artex/Matexi • Brussels Office for Architecture • NAV, de Vlaamse Architectenorganisatie • Vlaamse Huisvestingsmaatschappij • Zonnige Kempen • 3E • Bureau Bouwtechniek • Cenergie bvba • Decysis bvba • Grontmij Atenco nv • Ingenium • REUS • Studiebureau R. Boydens bvba • VK Engineering • K.U.Leuven, Labo Agrarische Bouwkunde • UGent, Onderzoeksgroep Biosysteemtechniek • VITO • Centrum Duurzaam Bouwen • Dialoog vzw • Kamp C • Passiefhuis-Platform vzw • Technologisch Instituut vzw Tijdens de startvergadering (8 september 2006) werd hen het project voorgesteld: doelstellingen, strategie en onderzoeksplanning. De daaropvolgende vergadering voor de gebruikersgroep was op 20 september 2007. De komende vergadering met de gebruikersgroep is gepland op 4 september 2008. Na elke vergadering is er ruimte om feedback voorzien. Na elke vergadering krijgen de leden van de gebruikerscommissie ook een verslag van de vergadering toegestuurd.


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Publicaties in tijdschriften en presentatie op conferenties Er zijn reeds verscheidene papers ingediend en aanvaard voor publicatie in een internationaal tijdschrift. De projectresultaten zijn ook reeds voorgesteld op meerdere internationale conferenties, waarvan de desbetreffende papers zijn opgenomen in de proceedings: Journal papers ingediend Costola D., Blocken B., Hensen, J.L.M., Overview of pressure coefficient data in building energy simulation programs, Building and Environment, Submitted. Briggen P.M., Blocken B., Schellen H.L. (2008), Wind-driven rain on the facade of a monumental tower: numerical simulation, full-scale validation and sensitivity analysis, Building and Environment, Submitted. Blocken B., Deszö G., van Beeck J., Carmeliet J. (2008). The mutual influence of two buildings on their wind-driven rain exposure and comments on the obstruction factor, Journal of Wind Engineering and Industrial Aerodynamics, Submitted. Persoon J., Blocken B. (2008), Pedestrian wind comfort around a large football stadium in an urban environment: CFD simulation, validation and application of the new Dutch wind nuisance standard, Journal of Wind Engineering and Industrial Aerodynamics, Submitted. Tablada A., Blocken B., Carmeliet J., de Troyer F., Verschure H. (2008), On natural ventilation and thermal comfort in compact urban environments – the Old Havana case, Building and Environment, Submitted. Abuku M., Blocken B., Poesen J., Roels S. (2008), Surface phenomena at raindrop impact on porous materials, Atmospheric Environment, Submitted. Steeman H., T’joen C., Van Belleghem M., Janssens A., De Paepe M., Evaluation of the different definitions of the convective mass transfer coefficient for water evaporation into air, International Journal of Heat and Mass Transfer, Submitted. Steeman H., Janssens A., De Paepe M., On the applicability of the heat and mass transfer analogy in indoor air flows, International Journal of Heat and Mass Transfer, Under Review. geaccepteerd Blocken B., Moonen P., Stathopoulos T., Carmeliet J. (2008). A numerical study on the existence of the Venturi-effect in passages between perpendicular buildings, Journal of Engineering Mechanics – ASCE, Accepted for publication. Abuku M., Blocken B., Nore K., Thue J.V., Carmeliet J., Roels S. (2008), On the validity of numerical wind-driven rain simulation on a rectangular low-rise building under various oblique winds, Building and Environment, In press. Blocken B., Stathopoulos T., Carmeliet J. (2008), Wind environmental conditions in passages between two long narrow perpendicular buildings, Journal of Aerospace Engineering – ASCE, In press. IWT SBO project 050154 – Heat, air and moisture performance engineering - A whole building approach Tweede jaarlijks rapport

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Abuku M., Janssen H., Roels S. (2008), Impact of wind-driven rain on historic brick wall buildings in a moderately cold and humid climate: numerical analyses of mould growth risk, indoor climate and energy consumption, Energy and Buildings, in press. doi:10.1016/j.enbuild.2008.07.011. Abuku M., Janssen H., Poesen J., Roels S. (2008), Impact, absorption and evaporation of raindrops at building facades, Building and Environment, in press. doi:10.1016/j.buildenv.2008.02.001. gepubliceerd Loomans M., Houdt W. v., Lemaire A. D., Hensen, J. L. M. (2008), Performance assessment of an operating theatre design using CFD simulation and tracer gas measurements, Indoor and Built Environment 17 (4) 299-312. Hoof J. v., Hensen J. L. M. (2007), Quantifying the relevance of adaptive thermal comfort models in moderate thermal climate zones, Building and Environment 42 (1) 156-170. Saelens D., Roels S., Hens H. (2008), Strategies to improve the energy performance of multiple-skin facades, Building and Environment 43(4) 638-650. Beausoleil-Morrison I., Hensen, J. L. M. (2008), Inaugural editorial, Journal of Building Performance Simulation 1 (1), p. 1. Lain M., Zmrhal V., Hensen, J. L. M. (2008), Low-energy cooling of buildings in central Europe - Case studies, International Journal of Ventilation 7 (1) 11-21. Blocken B., Carmeliet J. (2008), Guidelines for the required time resolution of meteorological input data for wind-driven rain calculations on buildings, Journal of Wind Engineering and Industrial Aerodynamics 96(5) 621-639. Persoon J., van Hooff T., Blocken B., Carmeliet J., de Wit M.H. (2008), On the impact of roof geometry on rain shelter in football stadia, Journal of Wind Engineering and Industrial Aerodynamics 96(8-9) 1274-1293. Blocken B., Stathopoulos T., Saathoff P., Wang X. (2008), Numerical evaluation of pollutant dispersion in the built environment: comparisons between models and experiments, Journal of Wind Engineering and Industrial Aerodynamics 96(10-11) 1817-1831. Blocken B., Carmeliet J. (2008), Pedestrian wind conditions at outdoor platforms in a high-rise apartment building: generic sub-configuration validation, wind comfort assessment and uncertainty issues, Wind and Structures 11(1) 51-70. Blocken B., Stathopoulos T., Carmeliet J. (2007), CFD simulation of the Atmospheric Boundary Layer: wall function problems, Atmospheric Environment 41(2) 238-252. Blocken B., Carmeliet J. (2007), On the errors associated with the use of hourly data in wind-driven rain calculations on building facades, Atmospheric Environment 41(11) 2335-2343. IWT SBO project 050154 – Heat, air and moisture performance engineering - A whole building approach Tweede jaarlijks rapport

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Blocken B., Carmeliet J., Stathopoulos T. (2007), CFD evaluation of the wind speed conditions in passages between buildings – effect of wall-function roughness modifications on the atmospheric boundary layer flow, Journal of Wind Engineering and Industrial Aerodynamics 95(9-11), 941-962 Blocken B., Roels S., Carmeliet J. (2007), A combined CFD-HAM approach for winddriven rain on building facades, Journal of Wind Engineering and Industrial Aerodynamics 95(7), 585-607. Janssen H., Blocken B., Roels S., Carmeliet J. (2007), Wind-driven rain as a boundary condition for HAM simulations: analysis of simplified modelling approaches, Building and Environment 42(4) 1555-1567. Blocken B., Carmeliet J. (2007), Validation of CFD simulations of wind-driven rain on a low-rise building façade, Building and Environment 42(7), 2530–2548. Janssen H., Blocken B., Carmeliet J. (2007), Conservative modelling of the moisture and heat transfer in building components under atmospheric excitation, International Journal of Heat and Mass Transfer 50 (5-6)1128-1140. Steeman H., Janssens A., Carmeliet J., De Paepe M., Modelling indoor air and hygrothermal wall interaction in building simulation: Comparison between CFD and a well-mixed zonal model, Building and Environment, In Press. Proceedings gepubliceerd Defraeye T., Blocken B., Carmeliet J.(2008), On the use of CFD in the analysis of the convective heat transfer coefficient distribution on building facades, Proceedings of the 4th International conference on Advances in Wind And Structures, Jeju, Korea. Defraeye T., Blocken B., Carmeliet J.(2008), Analysis of the exterior convective heat transfer coefficients of a cubic building with CFD, Proceedings of the 8th Symposium on Building Physics in the Nordic Countries, Copenhagen, Denmark. Van Belleghem M., Steeman H., Steeman M., Janssens A., De Paepe M. (2008), Design of a test chamber for investigation of moisture transport in air flows and porous materials, Proceedings of 8th Symposium on Building Physics in the Nordic Countries, Copenhagen, Denmark . Van Belleghem M., Steeman H., Canière H., Janssens A., De Paepe M. (2008), Design of a test chamber for moisture transport experiments in air flows and porous materials, Proceedings of the 6th International Conference on Heat transfer, Fluid Mechanics & Thermodynamics, Pretoria, South-Africa. Steeman H., Janssens A., De Paepe M. (2008), Coupling moisture transport in air flows and porous materials using CFD, Proceedings of 8th Symposium on Building Physics in the Nordic Countries, Copenhagen, Denmark. Steeman H., Janssens A., De Paepe M. (2008), Modelling heat and moisture transfer IWT SBO project 050154 – Heat, air and moisture performance engineering - A whole building approach Tweede jaarlijks rapport

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between air flows and hygroscopic porous materials with CFD, Proceedings of the 6th International Conference on Heat transfer, Fluid Mechanics & Thermodynamics, Pretoria, South-Africa. Steeman, H, Janssens A, De Paepe M. (2008), A coupled CFD-material model for the prediction of heat and moisture fluxes to hygroscopic porous materials, Proceedings of the 19th International Symposium on Transport Phenomena, 17/8-20/8, Reykjavik, Iceland. Vreenegoor R.C.P., Vries B. de, Hensen J.L.M. (2008), Comparing district designs; screening analysis of the critical factors at the building level, Proceedings of the 9th International Conference on Design and Decision Support Systems in Architecture and Urban Planning, Leende, July 7-10, Eindhoven University of Technology, The Netherlands. Vreenegoor R.C.P., Vries B. de, Hensen, J.L.M. (2008), Energy saving renovation, analysis of critical factors at building level, Proceedings of the 5th International Conference on Urban Regeneration and Sustainability "The Sustainable City 2008", 24 - 26 September, Skiathos, Greece. Vreenegoor R.C.P., Hensen J.L.M. , Vries B. de (2008), Review of existing energy performance calculation methods for district use, Proceedings of the IBPSA-NVL 2008 Event, 9 October, Eindhoven University of Technology, The Netherlands. Struck C., de Wilde P., Hopfe C., Hensen J. (2008), An exploration of the option space in building design for uncertainty and sensitivity analysis with performance simulation, Proceedings of the 15th International Workshop of the European Group for Intelligent Computing in Engineering, July 2-4, Plymouth, UK. Michael T.M., Emmerich, Hopfe C., Marijt R., Hensen J., Struck C., Stoelinga P. (2008), Evaluating optimization methodologies for future integration in building performance tools, Proceedings of the 8th ACDM (Adaptive Computing in Design and Manufacture) Conference, 29th April -1st May, Engineers house, Clifton, Bristol, UK. Duska M., Lukes J., Bartak M., Drkal F., Hensen J. (2007), Trend in heat gains from office equipment, Proceedings of Indoor Climate of Buildings, Strbske Pleso, 28 Nov 1 Dec, SSTP, Bratislava. Forejt L., Drkal F., Hensen J. (2007), Assessment of operating room air distribution in a mobile hospital: field experiment based on VDI 2167, Proceedings of the 10th International Roomvent Conference, 13 - 15 June, Helsinki. Hensen J. L. M. (2007), O simulaciji karakteristika zgrade u promenljivoj zivotnoj sredini, Proceedings of the 38th International Congress on Heating, Refrigeration and Air-conditioning, 5 - 7 December, KGH, Belgrade, 57-69. Hojer O., Basta J., Hensen J. (2007), Design optimization study for an infrared heater using CFD and sensitivity analysis, Proceedings of the 10th International Roomvent Conference, 13 - 15 June, Helsinki.


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Hojer O., Basta J., Hensen J. (2007), Accuracy in evaluation of a view factor between radiant heater element and pyrometer sensor, Proceedings of Indoor Climate of Buildings, Strbske Pleso, 28 Nov - 1 Dec, SSTP, Bratislava. Hopfe C. J., Hensen J., Plokker W., Wijsman A. J. T. M. (2007), Model uncertainty and sensitivity analysis for thermal comfort prediction, Proceedings of the 12th Symposium for Building Physics, 19-31 March, Technische Universitat Dresden, 103112. Hopfe C. J., Hensen J., Plokker W. (2007), Uncertainty and sensitivity analysis for detailed design support, Proceedings of the 10th IBPSA Building Simulation Conference, 3-5 September, Tsinghua University, Beijing, 1799-1804. Hopfe C. J., Struck C., Kotek P., Schijndel A.W.M. v., Hensen, J., Plokker, W. (2007), Uncertainty analysis for building performance simulation - a comparison of four tools, Proceedings of the 10th IBPSA Building Simulation Conference, 3-5 September, Tsinghua University, Beijing, 1383-1388. Kotek P., Filip J., Kabele K., Hensen J. (2007), Technique of uncertainty and sensitivity analysis for sustainable building energy systems performance calculations, Proceedings of the 10th IBPSA Building Simulation Conference, 3-5 September, Tsinghua University, Beijing, 629-636. Lain M., Zmrhal V., Drkal F., Hensen J. (2007), Slab cooling system design using computer simulation, Proceedings of the Central Europe towards Sustainable Building - CESB Conference, 24 - 26 September, Czech Technical University, Prague. Lain M., Zmrhal V., Hensen J. (2007), Low-energy cooling for buildings in central Europe - case studies, Proceedings of the joint 2nd PALENC and 28th AIVC Conference, 27 - 29 September, Crete. Loomans M., Melhado M., Zoon W., Hensen J. (2007), Performance based building and its application to the operating theatre, Proceedings of the 12th Symposium for Building Physics, 19-31 March, Technische Universitat Dresden, 681-688. Melhado M., Hensen J. L. M., Loomans M. (2007), Performance based design for ventilation systems of operating rooms using numerical simulation - discussing the methodology, Proceedings of the Clima 2007, 9th REHVA World Congress, 10 - 14 June, Helsinki. Struck C., Kotek P., Hensen J. (2007), On incorporating uncertainty analysis in abstract building performance simulation tools, Proceedings of the 12th Symposium for Building Physics, 19-31 March, Technische Universitat Dresden, 193-205. Struck C., Hensen J. (2007), On supporting design decisions in conceptual design addressing specification uncertainties using performance simulation, Proceedings of the 10th IBPSA Building Simulation Conference, 3-5 September, Tsinghua University, Beijing, 1434-1439.


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Trcka M., Wetter M., Hensen J. (2007), Comparison of co-simulation approaches for building and HVAC/R system simulation, Proceedings of the 10th IBPSA Building Simulation Conference, 3-5 September, Tsinghua University, Beijing, 1418-1425. Trcka M., Hensen, J. (2007), Case studies of co-simulation for building performance prediction, Proceedings of the 38th International Congress on Heating, Refrigeration and Air-conditioning, 5 - 7 December, KGH, Belgrade. Ulukavak Harputlugil G., Hensen J., de Wilde P. (2007), Simulation as a tool to develop guidelines for the design of school schemes for four climatic regions of Turkiye, Proceedings of the 10th IBPSA Building Simulation Conference, 3-5 September, Tsinghua University, Beijing, 1805-1812. Yahiaoui A., Hensen J., Soethout L., Paassen A. H. C. v. (2007), Developing webservices for distributed control and building performance simulation using run-time coupling, Proceedings of the 10th IBPSA Building Simulation Conference, 3-5 September, Tsinghua University, Beijing, 1327-1333. Zoon W., Heijkant S. A. M., Hensen J. L. M., Loomans M. G. L. C. (2007), Assessment of the performance of the airflow in an operating theatre, Proceedings of the 10th International Roomvent Conference, 13 - 15 June, Helsinki. Blocken B., Stathopoulos T. (2008), On the use of CFD for modelling air pollutant dispersion around buildings, 4th International Conference on Advances in Wind and Structures, May 28-30, Jeju Island, Korea Abuku M., Blocken B., Nore K., Thue J.V., Carmeliet J., Roels S. (2008), Validation of wind-driven rain simulation on a building for oblique winds, 4th International Conference on Advances in Wind and Structures, May 28-30, Jeju Island, Korea. Persoon J., Blocken B. (2008), Computational evaluation of wind comfort at the deck of a large football stadium in an urban environment with the new Dutch wind nuisance standard, 4th International Conference on Advances in Wind and Structures, May 2830, Jeju Island, Korea. Blocken B., Defraeye T., Neale A., Derome D., Carmeliet J. (2008), High-resolution CFD simulations of convective heat transfer coefficients at exterior building surfaces, 8th Symposium of Building Physics in the Nordic Countries, 16-18 June, Copenhagen, Denmark. Neale A., Derome D., Blocken B., Carmeliet J. (2008), Experimental and numerical determination of convective vapour transfer coefficients, 8th Symposium of Building Physics in the Nordic Countries, 16-18 June, Copenhagen, Denmark. van Hooff T., Persoon J., Blocken B., Carmeliet J., de Wit M.H. (2008), Spectators’ comfort in sports stadia: impact of roof geometry on wind-driven rain shelter, 8th Symposium of Building Physics in the Nordic Countries, 16-18 June, Copenhagen, Denmark.


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Maas R.P.W., Diepens J.F.L., Blocken B. (2008), Measurements and CFD simulations for the analysis of wind flow in a semi-enclosed athletics stadium, 8th Symposium of Building Physics in the Nordic Countries, 16-18 June, Copenhagen, Denmark. Pegge E.A., Blocken B., De Wit M., Carmeliet J., Bosschaerts W. (2008), Measurements and simulations of airflow in a mechanically ventilated active façade, 8th Symposium of Building Physics in the Nordic Countries, 16-18 June, Copenhagen, Denmark. Neale A., Blocken B., Derome D., Carmeliet J. (2007), Coupled simulation of vapour flow between air and a porous material, Paper for the Conference Performance of Exterior Envelopes of Whole Buildings IX, 2-7 December, Sheraton Sand Key Resort, Clearwater Beach, Florida, 11 pages. Blocken B., Carmeliet J. (2007), Wind-driven rain assessment on buildings using climatic databases: which time resolution is needed?, Paper for the Conference Performance of Exterior Envelopes of Whole Buildings IX, 2-7 December, Sheraton Sand Key Resort, Clearwater Beach, Florida, 13 pages. Linden W. van de, Loomans M., Hensen J.L.M. (2008), Adaptive thermal comfort explained by PMV, Proceedings Indoor Air 2008 (paper 573), Copenhagen, Denmark. van Oeffelen E.C.M., Loomans M., Wit M.H. de, Marken Lichtenbelt W.D. van, Frijns A.J.H. (2008), Application of a thermophysiological model for assessing nonuniform thermal environments, Proceedings Indoor Air 2008 (paper 225), Copenhagen, Denmark. Schellen, L., Marken Lichtenbelt W.D. van, Wit, M. de, Loomans M.. Frijns A., Toftum J. (2008), Thermal comfort, physiological responses and performance during exposure to a moderate temperature drift, Proceedings Indoor Air 2008 (paper 555), Copenhagen, Denmark. Zoon W.A.C., Loomans M.G.L.C., Hensen J.L.M. (2008), Pre-investigation into sensitivity analysis of use and design parameters to the ventilation efficiency in an operating room, Proceedings Indoor Air 2008 (paper 985), Copenhagen, Denmark. Abuku M., Janssen H., Roels S. (2008), Wind-driven rain impact on historical brick wall buildings, Proceedings of Nordic Symposium on Building Physics 2008, Copenhagen, Denmark, 16-18 June, 245-252. Abuku M., Janssen H., Roels S. (2007), Numerical simulation of absorption and evaporation of wind driven rain at building facades, Proceedings of the 12th Symposium for Building Physics, Dresden, Germany, 588-595. Abuku M., Blocken B., Carmeliet J., Roels S. (2006), A status report of wind-driven rain research at the Laboratory of Building Physics, K.U.Leuven, Proceedings of the Fourth International Symposium on Computational Wind Engineering, Yokohama, Japan, July 16 – 19.


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Abuku M., Janssen H., Poesen J., Roels S. (2008), Surface phenomena of wind-driven raindrops on porous building walls, Proceedings of the IEA ECBCS Annex 41 Closing Seminar, June 19, (C. Rode, editor), Dept. of Civil Engineering, Technical University of Denmark, Kgs. Lyngby, Denmark, 93-104. Janssen H., Roels S. (2008), The dependable characterisation of the moisture buffer potential of interior elements, Proceedings of Nordic Symposium on Building Physics 2008, Copenhagen, Denmark, 16-18 June, 669-676. Roels S., Janssen H. (2008), Characterisation of the hygric inertia of a room for a reliable prediction of the interior humidity variations, Proceedings of Nordic Symposium on Building Physics 2008, Copenhagen, Denmark, 16-18 June, 677-684. Roels S. (2008), IEA Annex 41 Subtask 2: interlaboratory comparison of vapour transmission properties and sorption isotherm of gypsum board, Proceedings of Nordic Symposium on Building Physics 2008, IEA ECBCS Annex 41, Closing Seminar, Copenhagen, Lyngby, 19 June, 61-68. ingediend Goethals K., Janssens A. (2008), Sensitivity analysis of thermal predictions to convective heat transfer at internal building surfaces, submitted to the Building Physics Symposium, Leuven, Belgium. Costola D., Blocken B., Hensen, J.L.M. (2008), Uncertainties due to the use of surface averaged wind pressure coefficients, Proceedings of the 29th AIVC Conference, Kyoto, Paper accepted for publication. Mirsadeghi M., Blocken B., Hensen, J.L.M. (2008), Validation of external BES-CFD coupling by inter-model comparison, Proceedings of the 29th AIVC Conference, Kyoto, Paper accepted for publication. Costola D., Blocken B., Hensen, J.L.M. (2009), A comparison of generic pressure coefficient for indoor air flow studies, Proceedings of the 4th International Building Physics Conference, Istanbul, Paper in review, abstract accepted. Mirsadeghi M., Costola D., Blocken B., Hensen, J.L.M. (2009), Towards the application of distributed simulation in HAM engineering, Proceedings of the 4th International Building Physics Conference, Istanbul, Paper in review, abstract accepted. Van Hooff T., Blocken B. (2008), CFD evaluation of natural ventilation strategies in a large semi-enclosed stadium in an urban environment, Building Physics Symposium, 29-31 October, Leuven, Belgium. Blocken B., Carmeliet J. (2008), Comparative evaluation of different calculation methods for wind-driven rain on buildings, Building Physics Symposium, 29-31 October, Leuven, Belgium.


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Blocken B., Stathopoulos T., Carmeliet J. (2008), CFD applications in urban aerodynamics, 4th International Building Physics Conference, 15-18 June, Istanbul, Turkey. Van Hooff T., Blocken B. (2008), Evaluation of natural ventilation in a large football staduim with CFD, 4th International Building Physics Conference, 15-18 June, Istanbul, Turkey. Blocken B., Derome D., Carmeliet J. (2008), A review of research on rain water runoff from building facades, 12th Canadian Conference on Building Science and Technology, May 6-8, Montreal, Quebec, Canada. Andere tijdschriften (professionele journals) Linden M. van der, Loomans M., Hensen J. L. M. (2008), Adaptief thermisch comfort verklaard met Fanger-model, TVVL Magazine 37 (7-8) 18-23. Hensen J. (2007), De unit Building Physics & Systems aan de TU/e, TVVL Magazine 36 (2) 60-61.

Interne rapporten en meetings Publicaties in internationale tijdschriften en voorstellingen op internationale conferenties worden in de loop van het project aangevuld met interne technische rapporten en software handleidingen, om de uitwisseling van kennis tussen de verschillende onderzoekers te vergemakkelijken. Deze rapporten zullen ook ter beschikking gesteld worden aan de gebruikersgroep:

• • • • • •

Goethals K., Janssens A. (2008), Literature review of diffuser modelling in computational fluid dynamics, Internal report SBO project IWT-050154. Goethals K., Janssens A. (2008), Sensitivity analysis of predicted convective heat transfer at internal building surfaces to diffuser modelling in computational fluid dynamics, Internal report SBO project IWT-050154. Goethals K., Janssens A. (2007), Feasibility study of the PASLINK cell, Internal report SBO project IWT-050154. User guide for coupling ESP-r and Fluent Introduction to HAMFEM Inlet velocity profiles applied to large inlet openings in CFD-AFN coupled simulation

Daarenboven zijn er ook in het tweede projectjaar twee stuurgroepvergaderingen geweest (7 februari en 27 augustus 2008) waar alle onderzoekers hun resultaten voorstelden. Daarna volgde een collectieve bespreking van de verdere onderzoeksstrategie en planning.

Cursussen, workshops, conferenties en aanverwante activiteiten De uit het onderzoeksprogramma voortvloeiende kennis en expertise worden bekendgemaakt op studiedagen, cursussen, conferenties en workshops gericht naar de belanghebbende actoren uit zowel de bouwsector als de wetenschappelijke wereld. Daarenboven wordt de verworven kennis reeds aangewend in aanverwante onderzoeksprojecten en in industriële opdrachten. Hier volgt een overzicht van deze activiteiten:


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Cursussen en workshops • PhD Summer Course: Heat and Mass Transport in Building Materials, Components and Whole Buildings: From Fundamentals to New Advances (Carmeliet J., Blocken B. (2de week in cursus gecoördineerd)), Lyngby, Denemarken, 26 mei-13 juni, 2008. Zomercursus waarop de basisprincipes maar ook een aantal van de laatste ontwikkelingen worden gedoceerd aan PhD-studenten, postdocs en mensen uit de praktijk. • CFD Workshop (20 september 2007): Workshop in het kader van het SBO project waarbij vooral de praktische toepassingen van CFD behandeld werden. Deze workshop werd georganiseerd door de SBO projectpartners in samenwerking met het KVIV en ATIC (technische vereniging van HVAC specialisten). • Maandelijkse PhD “progress” meetings aan Technische Universiteit Eindhoven: Meetings georganiseerd in de tweede helft van elke maand, waarop academische en industriële partners aanwezig zijn om informatie te bekomen over de nieuwe ontwikkelingen in WP4. De nauwe band met de industrie en praktijk waarborgt de praktische relevantie van het onderzoek (gecoördineerd door Jan Hensen). • PhD Symposium aan de Czech Technical University (CTU) in Praag (28-29 mei 2008): Een symposium met presentaties door PhD-studenten van TU/e en CTU over WholeBuilding Engineering en Building Performance Simulation. Het symposium omvatte ook een postertentoonstelling en een uitgebreid bezoek aan de laboratoriumfaciliteiten ter plaatse. • Cursus Energietechniek in gebouwen (IVPV-KVIV): Lezingen door A. Janssens en M. De Paepe. Conferenties en symposia • CFD symposium: Kwaliteit en betrouwbaarheid van CFD voor bouwkundige toepassingen in binnen- en buitenomgeving (10 juni 2008): Symposium mede georganiseerd door de unit BPS aan de Faculteit Bouwkunde van de TU Eindhoven (B. Blocken, J. Hensen, Wim Plokker, Chris Geurts) met als doelgroep zowel academici, architecten, adviesbureaus als mensen uit de industie. • Deelname aan de IEA Annex 41 Whole Building Heat, Air and Moisture Response (MOIST-ENG) met actieve deelname aan verschillende deelpakketen door verschillende partners. M. De Paepe en A. Janssens zijn co-editor voor het eindrapport voor het deel HAM-modelling (Subtask 1) en boundary conditions (Subtask 3). B. Blocken is ook co-editor van het deel boundary conditions (Subtask 3). S. Roels is editor voor het eindrapport over ‘Experimental analysis of moisture buffering’ (Subtask 2). Aanverwante onderzoeksprojecten ter ondersteuning van of resulterend uit het project • PhD project “Bruikbaarheid van CFD bij het prestatiegericht ontwerpen van het binnenmilieu” (TU Eindhoven – Wiebe Zoon, promotor: Jan Hensen) • PhD project “Building performance simulation for design support and optimization” (TU Eindhoven – Christina Hopfe, promotor: Jan Hensen) • PhD project “Distributed co-simulation of innovative building systems” (TU Eindhoven - Marija Trcka, promotor: Jan Hensen) • PhD project “Performance simulation for conceptual building and system design support” (TU Eindhoven, Christian Struck, promotoren: Jan Hensen, Paul Rutten) • PhD project “Distributed co-simulation of building automation and control systems” (TU Eindhoven, Azzedine Yahiaoui (promotor: Jan Hensen) IWT SBO project 050154 – Heat, air and moisture performance engineering - A whole building approach Tweede jaarlijks rapport

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FWO-Vlaanderen project “Numerieke modellering van gedwongen mengventilatie bij transitionele slot-Reynoldsgetallen” (K.U.Leuven – TU Eindhoven, Jan Carmeliet, Martin de Wit (promotoren), Bert Blocken (copromotor)).

Varia • Visiting professorship, Building Services Commissioning Association grant Kyoto University, 2 months (July + September) in 2007 (Jan Hensen) • Gebruik van de ontwikkelde modellen in industriële opdrachten door Vakgroep Mechanica van Stroming, Warmte en Verbranding (UGent): o INTERADVIES: Prestatietest van ultrasoonbevochtiger o SPE: Studie van de prestatie van een indirect gestookte droger

Opstellen jaarverslagen Het wetenschappelijk-technisch deel van het jaarverslag vormt een belangrijk onderdeel in de kennisoverdracht naar de gebruikersgroep betreffende de behaalde projectresultaten.

Ontwikkeling website Er werd een voorlopige website ontwikkeld in het eerste projectjaar waar externen de verslagen van vergaderingen met de gebruikerscommissie kunnen vinden alsook het eerste jaarrapport. De site is in het voorbije projectjaar niet verder ontwikkeld maar de ontwikkeling hiervan is één van de belangrijkste prioriteiten voor WP5 voor het komende projectjaar. Het is namelijk een belangrijk instrument om de interne werking en uitwisseling van verslagen en voorstellingen te vergemakkelijken en om externe geïnteresseerden te informeren over de activiteiten in het kader van het project.

2.3 Bescherming projectresultaten De in dit project ontwikkelde software wordt nog niet publiekelijk verspreid wat bescherming nog niet noodzakelijk maakt. Acties ter bescherming van de projectresultaten zijn daarom ook nog niet ondernomen.


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3 Financieel verslag 3.1 Prestatietabel De prestatietabellen voor de negen partners voor het projectjaar 2007-2008 worden bezorgd aan het IWT door K.U.Leuven LRD.


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3.2 Prognose voor komende projectjaar De inzet van mensen voor het projectjaar 2008-2009 wordt als volgt ingeschat. Partner KUL UG-FHC UG-AS WTCB-GS WTCB-BU

TUE PHYS DAI STO

Medewerker Thijs Defraeye Tadiwos Zerihun Desta Marnix Van Bellegem Demir-Ali Köse Kim Goethals Benoit Parmentier Luc Tisseghem Peter Wouters Gilles Flamant Christine Moureaux Philippe Voordecker Brieuc Meurisse Mohammad Mirsadeghi Daniel Costola Piet Houthuys Piet Standaert Filip Descamps Piet Delagaye

barema bursaal wet.mw. bursaal bursaal bursaal ir. tech. ir. ir. tech. tech bursaal bursaal dr.ir. dr.ir. dr.ir.-arch. ir.

maanden 12 12 12 12 12 11 6 ntb 3 3 6 5.5 12 12 0.25 0.25 ntb ntb

periode 01/09/08-31/08/09 01/09/08-31/08/09 01/09/08-31/08/09 01/09/08-31/08/09 01/09/08-31/08/09

01/09/08-31/08/09 01/09/08-31/08/09

De inzet van middelen wordt niet ingeschat, er zijn geen grote onderaannemingen of aankopen gepland.


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3.3 Financiële verantwoording De kostenstaten voor de negen partners voor het tweede projectjaar worden bezorgd aan het IWT door K.U.Leuven LRD. Hierbij dienen enkele opmerkingen gemaakt te worden:

•

•

•

•

•

WP1.1.1: Wegens problemen inzake personeel en administratieve problemen met betrekking tot de installatie van de windmasten (bouwvergunning, faillissement van de leverancier, ...) zijn de geplande manmaanden niet volledig gebruikt. Er wordt voorgesteld om enkele van deze manmaanden (voorzien voor het tweede projectjaar) te verplaatsen naar het derde projectjaar (zie onderstaande tabel). Ondanks deze wijzigingen is men van mening dat de doelstellingen van dit deelpakket tijdig bereikt kunnen worden. Tweede projectjaar Derde projectjaar Gepland Gerealiseerd Voorzien Voorgesteld Ingenieur 5 3 9 11 (+2) Technieker 3 1 4 6 (+2) WP2: In de loop van het tweede projectjaar (11/11/07) heeft Joachim Verhaegen (PhD 2) het project verlaten waarbij deze dus slechts ongeveer 2.3 maanden heeft gepresteerd in het voorbije projectjaar. Intussen is deze onderzoeksfunctie reeds weer ingevuld (15/04/08) door Tadiwos Zerihun Desta dewelke reeds 4.5 maanden heeft gepresteerd in het voorbije projectjaar. Daardoor zijn er voor deze onderzoeksfunctie slechts 7.8 maanden gepresteerd in het voorbije projectjaar. Aangezien de achterstand inzake onderzoek vrij gering is, lijkt een verlenging van dit werkpakket met de overblijvende manmaanden (4.2 maanden) niet nodig op dit moment. Het kan eventueel in een later stadium overwogen worden. WP3.1: Wegens problemen inzake personeel (de persoon van het WTCB die in dit werkpakket betrokken was heeft ontslag genomen) is er enige achterstand opgelopen inzake het gebruiksklaar maken van de Paslink cellen. Daardoor zijn ook de geplande manmaanden niet volledig gebruikt. Er wordt voorgesteld om een deel van deze manmaanden naar het derde projectjaar te verplaatsen en ze dus niet in te brengen dit projectjaar. De mogelijkheid tot samenwerking met UGent (met overdracht van budget) zal bekeken worden voor het verdere gebruik van de gegevens uit de PASLINK testen. Tweede projectjaar Derde projectjaar Gepland Gerealiseerd Voorzien Voorgesteld Ingenieur 9.5 3.5 5 11 (+6) Technieker 8 0.5 4 11.5 (+7.5) WP3.2: Doordat Marnix Van Belleghem slechts één maand in het eerste projectjaar heeft gepresteerd zijn er voor zijn positie op dit moment nog 11 manmaanden (uit het eerste projectjaar) niet gebruikt. Toch is er nauwelijks achterstand opgelopen in dit project. WP4: Door het laattijdig starten van de twee doctoraatsstudenten (november 2006) zijn er 2x2 manmaanden nog niet gebruikt in dit werkpakket. Er kan in een later stadium geopteerd worden om het project voor dit werkpakket te verlengen. De reden hiervoor is onder meer dat dit werkpakket als doel heeft om de kennis en informatie van alle andere werkpakketten te integreren. Het kan dus nuttig zijn als er, eens de


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andere werkpakketten klaar zijn, met deze integratie nog enkele maanden kan verdergegaan worden. Daarom is een huidige denkpiste dat het project voor dit werkpakket met 4 tot 6 maanden zou verlengd worden (voor beide studenten). De financiering hiervoor zou deels gevonden worden in de nog beschikbare manmaanden (2x2 manmaanden). Bijkomend zou voor de overige manmaanden een deel van het budget voor werking naar personeel kunnen overgedragen worden. In dit werkpakket zijn de werkingskosten immers niet zeer groot. WP5: Er is een achterstand opgelopen in dit werkpakket ten gevolge van personeelsproblemen. Daarom zijn niet alle geplande manmaanden gebruikt. Er wordt voorgesteld om een deel van de geplande manmaanden in het derde projectjaar uit te voeren. Aangezien er slechts een beperkt aantal manmaanden voorzien zijn voor dit werkpakket, kan het geplande werk zeker binnen de projectduur verwezenlijkt worden.


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4 Overzicht 4.1 Wetenschappelijk technisch WP1 Randvoorwaarden buiten WP1.1 Winddrukverdeling WP1.1.1 De testopstelling rondom het WINDHouse van het WTCB is operationeel. De windmasten rondom het gebouw zijn geïnstalleerd en ook winddrukken op de gebouwgevel kunnen gemeten worden. Deze opstelling zal dienen om validatiedata te voorzien voor WP 1.1.2. In het komende projectjaar zal de meetcampagne gestart worden. Een bijkomende dataset voor validatiedata zal verworven worden d.m.v. metingen op het VRT gebouw (Daidalos). WP1.1.2 Om te komen tot een betere voorspelling van de winddrukken op de gebouwgevel met behulp van numerieke stromingsmodellen (CFD) zijn er reeds verschillende RANS modellen, hybride technieken (RANS-LES) en LES modellen geëvalueerd. Dit werd gedaan voor stroming over een vierkante cilinder en een kubus, bij lage Reynoldsgetallen, waarvoor validatiedata beschikbaar was in de literatuur. De aandacht ging vooral naar de hybride technieken. Enkele hiervan waren reeds beschikbaar in de gebruikte software (Fluent) waar andere zelf geïmplementeerd werden. Uit deze studie bleken de hybride technieken een goede nauwkeurigheid te combineren met een acceptabele rekentijd en werd de meest performante hybride techniek geselecteerd. In het komende projectjaar zal in eerste instantie de data uit de literatuur (stromingsparameters en winddrukken) over een kubusvormig gebouw in atmosferische grenslaagstroming gebruikt worden voor verdere validatie van de hybridemodellen voor hoge Reynoldsgetallen. Later, als de data van het WINDHouse en het VRT gebouw beschikbaar zijn, zullen ook deze datasets gebruikt worden voor validatie om uiteindelijk te komen tot een conclusie inzake het gebruik van stromingsmodellen voor de voorspelling van winddrukken.

WP1.2 Invloed van slagregen WP1.2.1 In de voorbije periode is een testopstelling op het VLIET gebouw gemaakt waarmee gedetailleerde in-situ experimenten op slagregen op gebouwgevels kunnen uitgevoerd worden. Specifiek aan deze opstelling is dat ook onder andere de luchtsnelheden dichtbij de wand gemeten worden. Er zijn met deze opstelling reeds meerdere meetcampagnes uitgevoerd waardoor er verschillende uitgebreide datasets beschikbaar zijn. Deze werden reeds gebruikt als validatiedata voor numerieke modellen inzake slagregenvoorspelling dewelke reeds beschikbaar waren bij de partners. Hiermee kunnen deze modellen verder op punt gesteld worden wat een nauwkeurigere voorspelling van slagregenbelasting moet toelaten. WP1.2.2 Het beschikbare run-off model in de HAM code HAMFEM werd uitgebreid zodat ook absorptie en verdamping mee kunnen gemodelleerd worden in het proces wat een nauwkeurige voorspelling van slagregen op gevels toelaat. Er zijn geen verdere acties gepland voor dit onderdeel. WP1.2.3 Inzake de voorspelling van warmte- en massatransport op gebouwgevels werd de voorbije periode vooral de nadruk gelegd op het convectief (gedwongen) warmte- en massatransport. Er werd CFD (RANS) gebruikt om een nauwkeurigere en meer gedetailleerde voorspelling te geven van de overgangscoëfficienten op buitenoppervlakken. Hierbij werd in eerste instantie een kubusvormig gebouw beschouwd. De bestaande correlaties werden uitgebreid waarbij nu onder andere de invloed van windrichting en verdeling over de gebouwgevel mee ingerekend werd. Een experimentele opstelling (windtunnel) werd IWT SBO project 050154 – Heat, air and moisture performance engineering - A whole building approach Tweede jaarlijks rapport

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gebouwd om validatiedata voor de numerieke modellen te genereren. Daarenboven werd er een eerste prototype ontwikkeld voor een koppeling van CFD met een HAM model (HAMFEM) om o.a. een betere voorspelling van drogingsfenomenen (t.g.v. slagregenbelasting) te kunnen geven. In het komende jaar zijn experimenten gepland in de windtunnel om validatiedata inzake overgangscoëfficienten te geven alsook een verdere ontwikkeling en validatie van het CFD-HAM model.

WP2 Gebouwschil WP2.1 Ontwikkeling van een HAM model Wegens een personeelswissel is er inzake de software-uitbreiding nog geen vooruitgang geboekt. De nieuwe onderzoeker heeft zich wel reeds ingewerkt in de numerieke modellering. In het komende jaar zullen enkele numerieke technieken inzake de implementatie van luchttransport in een HAM code getest worden in een eenvoudige MATLAB code. Gebaseerd op deze resultaten zal de meest optimale methode geïmplementeerd worden in HAMFEM. Deze geüpgrade versie van HAMFEM zal dan gebruikt worden om de experimenten uit WP2.2 te simuleren.

WP2.2 Experimentele analyse op gebouwen Er werd een testopstelling geconstrueerd aan het VLIET gebouw die kan dienen om validatiedata te voorzien voor WP2.1. Deze experimenten dienen onder andere om het effect en het belang van luchtstroming en luchtlekkage door de gebouwschil op het hygrothermisch gedrag te bestuderen. De opstelling is zeer modulair opgebouwd wat in de toekomst ook andere verwante experimenten toelaat. Deze opstelling is reeds meerdere maanden aan het meten en de data is reeds gedeeltelijk verwerkt en geïnterpreteerd. Er werd een methodologie ontwikkeld wat snelle data-analyse toelaat. In het komende jaar is verdere verwerking van de data gepland (hygrothermische analyse). Er zullen ook natuurlijke en gedwongen convectiesystemen geïnstalleerd worden in de testopstelling. Hiermee zal een nieuwe meetcampagne gestart worden. Daarenboven zal een testopstelling geïnstalleerd worden waarmee de luchtdichtheid van Celit 3D tegels getest kan worden. Hierbij zal ook de inwendige condensatie in dit materiaal gemonitord worden.

WP3 Binnenomgeving WP3.1 Convectieve warmte-uitwisseling en zomercomfort WP3.1.1 Inzake het onderzoek naar de convectieve warmte-uitwisseling aan binnenoppervlakken t.g.v. ventilatie is er een testprotocol ontwikkeld voor de PASLINK cellen die zullen gebruikt worden voor de experimentele analyse. In het komende projectjaar zullen de PASLINK cellen operationeel gemaakt worden en zal de meetcampagne starten. Deze dienen om onder andere validatiedata te genereren voor de numerieke analyse van deze fenomenen met CFD. Op numeriek vlak zijn reeds verschillende modelleringstechnieken voor inlaatdiffusers getest wat belangrijk is voor een juiste voorspelling van de warmteoverdracht. In het komende jaar zal het gebruik van bestaande correlaties voor de voorspelling convectieve overgangscoëfficienten geëvalueerd worden op basis van CFD simulaties voor verschillende stromingsregimes. WP3.1.2 Voor dit deelpakket zullen ook de PASLINK cellen gebruikt worden. Zoals reeds vermeld is het testprotocol reeds opgesteld en worden de experimenten komend jaar gestart. WP3.1.3 In dit deelpakket is een 3D zonneprocessor ontwikkeld. Er werd een eenvoudige testopstelling ontworpen en geconstrueerd om validatiedata voor deze processor te genereren. In het komend jaar is gepland om de meetdata te gebruiken om het zonneprocessor model te valideren. IWT SBO project 050154 – Heat, air and moisture performance engineering - A whole building approach Tweede jaarlijks rapport

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WP 3.1.4 Er werd door één van de industriële partners een meetcampagne opgezet in een kantoorgebouw. Er is reeds een eerste dataset beschikbaar. In het komende jaar zal deze meetcampagne verdergezet worden. Daarenboven zal een analyse van de resultaten volgen.

WP3.2 Ontwikkeling van een CFD-HAM model WP3.2.1 Er werd een testopstelling geconstrueerd. Het gaat om een klimaatkamer waar zowel temperatuur, relatieve vochtigheid en luchtstroming kunnen gecontroleerd en gemeten worden. Deze opstelling is nu operationeel en er zijn reeds eerste metingen gebeurd inzake de gevoeligheid van de regeling op temperatuur en relatieve vochtigheid. Ook het inlaatprofiel werd reeds opgemeten. In het komende projectjaar zijn meetcampagnes gepland inzake het hygrothermisch gedrag van poreuze materialen, onder andere voor het valideren van het gekoppelde CFD-HAM model. Ook het effect van vochtbuffering zal experimenteel onderzocht worden. Daarenboven zullen ook experimenten inzake dampovergangscoëfficienten uitgevoerd worden. WP 3.2.2 Er werd in de gebruikte CFD code (Fluent) niet-isotherm damptransport in poreuze materialen geïmplementeerd. Daarenboven werd de invloed van hysteresis ook geïmplementeerd. Het model is reeds gevalideerd met experimenten (labo schaal). De testopstelling ontwikkeld in WP 3.2.1 dient onder andere om validatiedata op grotere schaal aan te reiken. WP3.2.3 Er werd een meetcampagne gestart in een lage-energie gebouw waarvan eerste datasets beschikbaar zijn. In het komende jaar volgt een analyse van de resultaten en er zullen daarenboven ook nog meetcampagnes opgezet worden in andere gebouwen.

WP4 Naar een geïntegreerde aanpak WP4.1 Ontwikkeling van een prototype software omgeving Er werden verschillende prototypes ontwikkeld waarbij verschillende softwarepakketten gekoppeld werden (runtime of extern). Elk van deze softwarepakketten wordt gebruikt in één of meerdere werkpakketten. Het doel van deze koppeling is een meerwaarde te creëren voor de analyse van diverse fenomenen vergeleken met het gebruik van de softwarepakketten afzonderlijk. Daarbij kan de koppeling runtime gebeuren of extern. Bij dit laatste wordt de informatie van de analyse met een bepaalde software, bv. inzake de voorspelling van de drukcoëfficienten met CFD, extern aangeleverd aan ESP-r om voor een accuratere analyse te zorgen dan enkel met de stand-alone ESP-r simulatie. Een eerste prototype omvat de runtime koppeling van ESP-r met CFD software. De resultaten inzake een simulatie van convectief warmtetransport in de binnenomgeving werden vergeleken met de stand-alone ESP-r simulatie waarbij significante verschillen opgemerkt werden. Er werd een eerste stap gezet inzake een tweede prototype waarbij de informatie van CFD simulaties van de buitenomgeving (drukcoëfficienten en overgangscoeffienten) gebruikt wordt in de ESP-r simulaties. Hier wordt de informatie van CFD extern afgeleverd aan ESP-r. In een derde prototype werd de runtime koppeling van ESP-r en HAMFEM ingezet. Dit dient om een betere voorspelling inzake het hygrothermisch gedrag van bouwdelen te geven. Bij al deze prototypes werd veel aandacht besteed aan een efficiënte uitwisseling van informatie. In het komende projectjaar zullen deze prototypes verder ontwikkeld worden en gebruikt worden om meer realistische problemen te simuleren. Hierbij is de input van de andere werkpakketten cruciaal.

WP4.2 Ontwikkeling van een coupling necessity decision procedure Tegenover de meerwaarde van de koppeling staat uiteraard een grotere rekentijd. Daarmee is het belangrijk dat de koppeling enkel gebeurt wanneer de meerwaarde van de gekoppelde IWT SBO project 050154 – Heat, air and moisture performance engineering - A whole building approach Tweede jaarlijks rapport

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simulatie significant is. Daarom werd er veel aandacht besteed een procedure dewelke de effectieve noodzaak van de koppeling van twee softwareprogramma’s evalueert. Dit werd in eerste instantie gedaan voor de voorspelling van drukcoeffiienten en warmteovergangscoëfficienten. In het komende projectjaar is een verdere uitwerking hiervan gepland.

WP4.3 Experimentele validatie Er zijn reeds twee validatiecases geselecteerd, namelijk het WINDHouse van het WTCB en het Unilin gebouw waarbij de eerste stappen gezet zijn inzake de experimentele analyse zoals vermeld in de vorige werkpakketten. Het Unilin gebouw is reeds gebruikt in de numerieke analyse. De simulaties zullen ook gebruikt worden om de tekorten inzake meetdata te identificeren zodat deze kunnen aangevuld worden. In het komende jaar zullen deze cases bestudeerd worden d.m.v. numerieke modellen en kunnen de resultaten vergeleken worden met experimentele resultaten.

WP5 Oprichten van een kennisplatform WP5.1 Strategische en geïntegreerde planning van onderzoeksactiviteiten Er zijn reeds verscheidene contacten geweest tussen de verschillende partners inzake het behandelen en uitvoeren van projecten en de bijhorende samenwerking. Daarenboven werd een eerste eenvoudige website ontwikkeld om de interne uitwisseling van informatie maar ook de disseminatie naar de bouwsector te vergemakkelijken. Er werden ook reeds verscheidene workhops gehouden o.a. inzake CFD en warmte en vochtproblematiek in historische gebouwen. In het komende projectjaar is een verdere uitbreiding van de website gepland. Ook de ontwikkeling van een hogere cursus inzake warmte- en vochttransport in gebouwen is gepland. Daarenboven zullen er ook nog workshops georganiseerd worden om de kennis van de partners in verschillende deeldomeinen te dissimineren. Verdere stappen in de samenwerking tussen de partners inzake industriële opdrachten zijn ook voorzien.

WP5.2 Strategische implementatie van test- simulatie faciliteiten Een inventarisatie van de testfaciliteiten van de verschillende partners is gestart. Daarenboven worden ook de numerieke simulatietools geïnventariseerd. Zo een inventaris is belangrijk om de ontbrekende experimentele faciliteiten en simulatiepakketten te identificeren alsook om de beschikbare faciliteiten optimaal te gebruiken. In het komende projectjaar zullen verdere stappen in deze inventarisatie ondernomen worden.

Haalbaarheid van het project Ten gevolgen van enkele personeelswissels en -tekorten hebben sommige werkpakketten achterstand opgelopen inzake onderzoek: • WP1.1.1: Er is enige achterstand inzake de geplande experimenten ten gevolge van een personeelstekort aan het WTCB. Komend jaar is er een werknemer beschikbaar die zich met dit deelpakket zal bezighouden om zo de nodige data tijdig te kunnen voorzien voor de numerieke simulaties van WP1.1.2. • WP2.1: Ten gevolge van een personeelswissel is er enige achterstand inzake de numerieke modellering maar deze kan ingehaald worden. • WP3.2: De onderzoeker (UGent) is laattijdig gestart (slechts één maand in het eerste projectjaar gepresteerd). Niettemin is het geplande werk reeds uitgevoerd door collega’s die op andere projecten werken. Er is dus geen achterstand opgelopen.


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• •

WP4: De twee doctoraatsstudenten zijn pas twee maanden na de aanvang van het project gestart. De opgelopen achterstand is niet aanzienlijk en kan opgevangen worden. WP5: Door een personeelstekort aan het WTCB is het geplande werk slechts deels uitgevoerd. Het komende projectjaar zal dit echter gecompenseerd worden wat geen probleem vormt gezien het geringe aantal manmaanden dat hiervoor voorzien is.

De opgelopen achterstand is dus niet van die aard dat de haalbaarheid van het project in vraag gesteld moet worden.

4.2 Valorisatie Hieronder volgt een kort overzicht van de valorisatie-acties en de verdere planning voor disseminatie. Dit omvat zowel interne disseminatie tussen de verschillende partners als disseminatie naar verscheidene sectoren van de bouwnijverheid toe, zowel voor leden van de gebruikerscommissie als voor externen. Voor een uitgebreid overzicht wordt verwezen naar sectie 2.2. Interne disseminatie • Halfjaarlijkse stuurgroepvergaderingen. Deze dienen om het werk van de onderzoekers aan de rest van de partners voor te stellen waarna feedback volgt. • Contactmomenten tussen onderzoekers van verschillende werkpakketten. Deze zijn noodzakelijk aangezien integratie en koppeling van de verworven kennis van de werkpakketten centraal staat binnen het project. • Interne rapporten. Dit omvat literatuurstudies en software handleidingen e.d. Externe disseminatie • Website. Er werd een website ontwikkeld. Voorlopig dient deze hoofdzakelijk voor interne uitwisseling van documenten tussen de verschillende partners. Deze website zal uitgebreid worden zodat leden van de gebruikerscommissie alsook externe geïnteresseerden er nog meer informatie over het project en de partners kunnen terugvinden. • Jaarverslagen. Door middel van jaarverslagen wordt een overzicht gegeven van de activiteiten van de verschillende partners voor het voorbije jaar. Deze zijn beschikbaar op de website. • Workshops: Er zijn reeds twee workshops georganiseerd vanuit het project, rechtstreeks gericht voor de leden van de gebruikerscommissie (CFD workshop 2007, Workshop warmte-, lucht- en vochtproblematiek bij historische gebouwen 2008). Daarenboven zijn de partners betrokken bij de organisatie van verschillende verwante cursussen en workshops. In het komende jaar zal er nog een workshop georganiseerd worden. Het onderwerp is echter nog niet bepaald. • Conferenties. Ook verscheidene conferenties werden reeds georganiseerd door één of meerdere van de projectpartners. Daarenboven werd het werk van de onderzoekers reeds gepresenteerd op verschillende internationale conferenties. • Industriële opdrachten. De projectresultaten zijn reeds gebruikt in de analyse bij industriële opdrachten. • Papers. Om de verworven kennis naar de onderzoekswereld kenbaar te maken zijn reeds verscheidene papers ingediend en gepubliceerd in internationale journals en conference proceedings.


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SBO project IWT Tweede jaarlijks rapport

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