DAFTAR ISI
HALAMAN JUDUL ..................................................................................
i
LEMBAR PENGESAHAN PEMBIMBING.............................................
ii
LEMBAR PENGESAHAN DOSEN PENGUJI........................................
iii
PERSEMBAHAN ......................................................................................
iv
MOTTO .....................................................................................................
v
KATA PENGANTAR ................................................................................
vi
ABSTRAK..................................................................................................
viii
TAKARIR ..................................................................................................
ix
DAFTAR ISI ..............................................................................................
x
DAFTAR TABEL .........................................................................................
xiv
DAFTAR GAMBAR..................................................................................
xvi
BAB I PENDAHULUAN 1.1. Latar Belakang ..............................................................................
1
1.2. Rumusan Masalah .........................................................................
2
1.3. Batasan Masalah............................................................................
2
1.4. Tujuan Penelitian...........................................................................
3
1.5. Manfaat Penelitian.........................................................................
3
1.6. Sistematika Penulisan……………………………………….. ........
3
BAB II LANDASAN TEORI 2.1. Desain ...........................................................................................
4
2.2. Kanopi ..........................................................................................
4
2.3. Spoiler dan Airfoil .........................................................................
5
2.3.1. Spoiler .................................................................................
5
2.3.2. Airfoil ..................................................................................
6
2.4. Karakteristrik Aliran Melewati sebuah Benda..................................
7
x
2.4.1. Pola aliran disekitar airfoil ...................................................
7
2.4.2. Pola aliran disekitar kendaraan.............................................
7
2.5. Gaya-gaya Aerodinamis..................................................................
8
2.5.1. Gaya hambat (drag force) ....................................................
9
2.5.2. Gaya angkat (lift force) ........................................................
11
2.5.3. Momen (lift force)................................................................
12
2.6. Properti Udara (Gas).................................. .....................................
13
2.6.1. Suhu (Temperature) .............................................................
13
2.6.2. Kerapatan (Density) .............................................................
14
2.7. Jenis-jenis aliran.................................. ...........................................
14
2.7.1. Aliran Inviscid .....................................................................
14
2.7.2. Aliran Viscous .....................................................................
15
2.8. Computational Fluid Dynamics ( CFD ) ........................................
16
BAB III METODOLOGI 3.1. Diagram Alir Perancangan dan Simulasi .......................................
18
3.2. Konsep Perancangan .....................................................................
19
3.2.1. Indentifikasi masalah ...........................................................
19
3.2.2. Pembuatan desain ................................................................
19
3.2.3. Pembuatan Meshing .............................................................
19
3.3. Jenis dan Sumber Data.................................. ..................................
19
3.3.1. Data primer..........................................................................
19
3.3.2. Data sekunder ......................................................................
20
3.4. Metode Pengumpulan Data...............................................................
20
3.4.1. Subyek penelitian ................................................................
20
3.4.2. Peralatan yang digunakan ....................................................
20
3.5. Metode Pengolahan Data............................................................... ..
26
3.6. Metode Analisis............................................................... ................
26
3.6.1. Analisis di software fluent....................................................
26
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BAB IV PENGUMPULAN DAN PENGOLAHAN DATA 4.1. Proses pengujian............................................................................
28
4.1.1 Proses pembuatan desain .....................................................
28
4.1.2 Mengubah sudut kemiringan dan menggabungkan (Union) ..
29
4.1.3 Menggabungkan (Assembly) ................................................
30
4.2. Mencari luas frontal menggunakan software Inventor 2008 ...........
31
4.3. Langkah-langkah pengujian ...........................................................
32
4.3.1. Mencari pusat massa dengan menggunakan software Inventor 2008 ....................................................................................
32
4.3.2. Import file Inventor ..............................................................
34
4.3.3. Merubah pusat massa ...........................................................
34
4.3.4 Membuat batasan benda uji ..................................................
35
4.3.5 Perbaikan desain ..................................................................
36
4.3.6 Pembuatan meshing .............................................................
37
4.3.7 Menentukan kondisi batas aliran fluida ................................
38
4.4. Pengujian CFD (Computational Fluid Dynamics)..........................
38
4.5. Hasil pengujian..............................................................................
39
4.5.1 Pressure ..............................................................................
43
4.5.2 Velocity................................................................................
45
BAB V ANALISA DAN PEMBAHASAN 5.1. Perhitungan gaya hambat, gaya angkat dan momen pada spoiler....
46
5.2. Pemilihan desain spoiler yang digunakan untuk kanopi .................
50
5.3. Penempatan spoiler pada kanopi ....................................................
51
5.3.1. Spoiler diletakkan di depan atas kanopi................................
51
5.3.2. Spoiler diletakkan di pusat massa (CG) kanopi ....................
52
5.3.3. Spoiler diletakkan di belakang kanopi ..................................
52
5.4. Hasil pengujian penempatan spoiler pada kanopi ...........................
52
5.4.1. Kanopi .................................................................................
53
5.4.2. Spoiler diletakkan di depan atas kanopi................................
53
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5.4.3. Spoiler diletakkan di belakang kanopi ..................................
54
5.4.4. Spoiler diletakkan di pusat massa (CG) kanopi ....................
54
5.5 Analisa gaya hambat .....................................................................
55
5.5.1. Kanopi-spoiler di depan .......................................................
55
5.5.2. Kanopi-spoiler di pusat massa..............................................
56
5.5.3. Kanopi-spoiler di belakang ..................................................
56
5.6 Analisa gaya angkat.......................................................................
57
5.6.1. Kanopi-spoiler di depan .......................................................
57
5.6.2. Kanopi-spoiler di pusat massa..............................................
58
5.6.3. Kanopi-spoiler di belakang ..................................................
58
5.7 Analisa momen..............................................................................
59
5.7.1. Kanopi-spoiler di depan .......................................................
59
5.7.2. Kanopi-spoiler di pusat massa..............................................
60
5.7.3. Kanopi-spoiler di belakang ..................................................
61
5.8. Perbandingan Pengujian kanopi menggunakan airfoil ....................
61
5.8.1. Kanopi-airfoil di depan dengan sudut 0° ..............................
62
5.8.2. Kanopi-airfoil di depan dengan sudut 20° ............................
62
5.9. Perbandingan selisih penambahan spoiler dan airfoil pada kanopi .
63
5.10. Analisa perhitungan massa spoiler .................................................
65
BAB VI KESIMPULAN DAN SARAN 6.1. Kesimpulan ...................................................................................
66
6.2 Saran .............................................................................................
67
DAFTAR PUSTAKA .................................................................................
68
LAMPIRAN ...............................................................................................
69
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DAFTAR TABEL Tabel 2.1. Koefisien hambat aerodinamis untuk beberapa kendaraan ..............
9
Tabel 4.1. Luas frontal desain spoiler model 1 ................................................ 31 Tabel 4.2. Luas frontal desain spoiler model 2 ................................................ 31 Tabel 4.3. Luas frontal kanopi, kanopi-spoiler dan kanopi-airfoil .................... 32 Tabel 4.3. Pusat massa desain spoiler model 1 ................................................ 33 Tabel 4.5. Pusat massa desain spoiler model 2 ................................................ 33 Tabel 4.6. Pusat massa kanopi, kanopi-spoiler dan kanopi-airfoil .................... 33 Tabel 4.7. Hasil koefisien drag pada pengujian CFD desain spoiler model 1 ... 40 Tabel 4.8. Hasil koefisien lift pada pengujian CFD desain spoiler model 1 ...... 40 Tabel 4.9. Hasil koefisien momen pada pengujian CFD desain spoiler model 1 ........................................................ ................................................................. 40 Tabel 4.10. Hasil koefisien drag pada pengujian CFD desain spoiler model 2 . 41 Tabel 4.11. Hasil koefisien lift pada pengujian CFD desain spoiler model 2 .... 41 Tabel 4.12. Hasil koefisien momen pada pengujian CFD desain spoiler model 2 .......................... .............................................................................................. 41 Tabel 4.13. Hasil Pengujian CFD pada kanopi ................................................ 41 Tabel 4.14. Hasil Pengujian CFD pada kanopi-spoiler di depan ...................... 42 Tabel 4.15. Hasil Pengujian CFD pada kanopi-spoiler di pusat massa (CG) .... 42 Tabel 4.16. Hasil Pengujian CFD pada kanopi-spoiler di belakang .................. 42 Tabel 4.17. Hasil Pengujian CFD pada kanopi-airfoil di depan 0° ................... 42 Tabel 4.18. Hasil Pengujian CFD pada kanopi-airfoil di depan 20° ................. 43 Tabel 5.1. Gaya drag pada spoiler model 1 ..................................................... 47 Tabel 5.2. Gaya lift pada spoiler model 1 ........................................................ 47 Tabel 5.3. Momen pada spoiler model 1 .......................................................... 48 Tabel 5.4. Gaya drag pada spoiler model 2 ..................................................... 48 Tabel 5.5. Gaya lift pada spoiler model 2 ........................................................ 49 Tabel 5.6. Momen pada spoiler model 2 .......................................................... 49
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Tabel 5.7. Gaya drag dan gaya lift pada kecepatan 25 m/s ............................... 50 Tabel 5.8. Gaya drag, gaya lift dan momen pada kanopi.................................. 53 Tabel 5.9. Gaya drag, gaya lift dan momen pada kanopi-spoiler di depan ........ 53 Tabel 5.10. Gaya drag, gaya lift dan momen pada kanopi-spoiler di pusat massa................................................................................................ 54 Tabel 5.11. Gaya drag, gaya lift dan momen pada kanopi-spoiler di belakang.. 54 Tabel 5.12. Gaya drag pada kanopi, kanopi-spoiler di depan, kanopi-spoiler di pusat massa dan kanopi-spoiler di belakang .............................. 55 Tabel 5.13. Gaya drag pada kanopi, kanopi-spoiler di depan, kanopi-spoiler di pusat massa dan kanopi-spoiler di belakang ............................. 57 Tabel 5.14. Momen pada kanopi, kanopi-spoiler di depan, kanopi-spoiler di pusat massa dan kanopi-spoiler di belakang .............................. 59 Tabel 5.15. Gaya drag, gaya lift dan momen pada kanopi-airfoil 0° ................ 62 Tabel 5.16. Gaya drag, gaya lift dan momen pada kanopi-airfoil 20°............... 63 Tabel 5.17. Penambahan spoiler dan airfoil pada kanopi ................................. 63 Tabel 5.18. Selisih penambahan spoiler dan airfoil pada kanopi ...................... 63
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DAFTAR GAMBAR Gambar 2.1. Kanopi pada umumnya ............................................................
5
Gambar 2.2. Kanopi pada sepeda motor .......................................................
5
Gambar 2.3. Model spoiler 1 ........................................................................
6
Gambar 2.4. Model spoiler 2 ........................................................................
6
Gambar 2.5. Gaya dan momen pada airfoil ..................................................
6
Gambar 2.6. (a) Distribusi tekanan dan (b) distribusi tegangan geser............
7
Gambar 2.7. Aliran udara disekitar airfoil ....................................................
7
Gambar 2.8. Pola aliran udara disekitar kendaraan .......................................
8
Gambar 2.9. Gaya dan momen aerodinamika ...............................................
9
Gambar 2.10. Koefisien gaya hambat 3D .....................................................
10
Gambar 2.11. Perbedaan aliran udara pada kendaraan ..................................
11
Gambar 2.12. Sudut serang angin .................................................................
12
Gambar 2.13. Persetujuan tanda untuk momen aerodinamika .......................
13
Gambar 2.14. Aliran laminar........................................................................
15
Gambar 2.15. Aliran turbulen.......................................................................
16
Gambar 2.16. Struktur komponen pada fluent ..............................................
17
Gambar 3.1. Diagram alir Perancangan dan Simulasi ...................................
18
Gambar 3.2. Ukuran desain spoiler model 1 .................................................
21
Gambar 3.3. Ukuran desain spoiler model 2 .................................................
21
Gambar 3.4. Ukuran desain airfoil ...............................................................
22
Gambar 3.5. Ukuran desain kanopi ..............................................................
22
Gambar 3.6. Proses Rotate di Software CAD ...............................................
23
Gambar 3.7. Proses extrude dari sketch ........................................................
24
Gambar 3.8. Perbaikan desain dan pendefinisian batasan aliran ...................
24
Gambar 3.9. Contour-contour pada software fluent ......................................
25
Gambar 3.10. Perhitungan dan membuat grafik di MS Excel .......................
26
Gambar 3.11. Diagram Alir Prosedur Simulasi di Software Fluent ...............
27
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Gambar 4.1. (a) Sketsa model spoiler dan (b) Desain 3D model spoiler di Inventor ............................................................................
29
Gambar 4.2. Mengubah sudut kemiringan desain 3D di AutoCAD ...............
30
Gambar 4.3. (a) Sebelum dan (b) sesudah proses Union ...............................
30
Gambar 4.4. Penggabungan atau assembly di software Inventor...................
31
Gambar 4.5. Mencari luas frontal desain ......................................................
32
Gambar 4.6. Mencari pusat massa desain .....................................................
33
Gambar 4.7. Proses Import File Inventor pada Software Gambit ..................
34
Gambar 4.8. Titik 0,0,0 sebelum dipindahkan ke titik pusat massa ...............
35
Gambar 4.9. Titik 0,0,0 menjadi titik pusat massa ........................................
35
Gambar 4.10. Batasan benda uji pada Software Gambit ...............................
36
Gambar 4.11. (a) Sebelum dan (b) sesudah proses proses Cleanup tools ......
36
Gambar 4.12. Mesh volume pada software gambit .......................................
37
Gambar 4.13. Penentuan batasan aliran fluida ..............................................
38
Gambar 4.14. Simulasi aliran fluida .............................................................
39
Gambar 4.15. Hasil analisis dari software fluent ...........................................
39
Gambar 4.16. Countur coefisien pressure ....................................................
43
Gambar 4.17. Countur static pressure ..........................................................
44
Gambar 4.18. Countur dynamic pressure .....................................................
44
Gambar 4.19. Countur total pressure ...........................................................
45
Gambar 4.20. Countur magnitude velocity ...................................................
45
Gambar 5.1. Grafik gaya drag pada semua sudut model spoiler 1 ................
47
Gambar 5.2. Grafik gaya lift pada semua sudut model spoiler 1 ...................
48
Gambar 5.3. Grafik Momen pada semua sudut model spoiler 1 ....................
48
Gambar 5.4. Grafik gaya drag pada semua sudut model spoiler 2 ................
49
Gambar 5.5. Grafik gaya lift pada semua sudut model spoiler 2 ...................
49
Gambar 5.6. Grafik Momen pada semua sudut model spoiler 2 ....................
50
Gambar 5.7. Grafik gaya drag dan gaya lift kedua desain spoiler .................
50
Gambar 5.8. Spoiler diputar dengan tetap sudut 20° .....................................
51
Gambar 5.9. Spoiler diletakkan di depan atas kanopi....................................
51
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Gambar 5.10. Spoiler diletakkan di pusat massa (CG) kanopi ......................
52
Gambar 5.11. Spoiler diletakkan di belakang kanopi ....................................
52
Gambar 5.12. Grafik gaya drag, lift dan momen pada kanopi .......................
53
Gambar 5.13. Grafik gaya drag, lift dan momen pada kanopi-spoiler di depan ................................................................................
53
Gambar 5.14. Grafik gaya drag, lift dan momen pada kanopi-spoiler di CG .
54
Gambar 5.15. Grafik gaya drag, lift dan momen pada kanopi-spoiler di belakang............................................................................
54
Gambar 5.16. Aliran udara kanopi-spoiler di depan......................................
55
Gambar 5.17. Aliran udara kanopi-spoiler di pusat massa ............................
56
Gambar 5.18. Aliran udara kanopi-spoiler di belakang .................................
56
Gambar 5.19. Countur pressure kanopi-spoiler di depan ..............................
57
Gambar 5.20. Countur pressure kanopi-spoiler di pusat massa.....................
58
Gambar 5.21. Countur pressure kanopi-spoiler di belakang .........................
58
Gambar 5.22. Velocity magnitude kanopi-spoiler di depan ...........................
59
Gambar 5.23. Velocity magnitude kanopi-spoiler di pusat massa ..................
60
Gambar 5.24. Velocity magnitude kanopi-spoiler di belakang ......................
61
Gambar 5.25. Kanopi-airfoil di depan dengan sudut 0° ................................
62
Gambar 5.26. Kanopi-airfoil di depan dengan sudut 20° ..............................
62
Gambar 5.27. Grafik selisih penambahan spoiler dan airfoil.........................
64
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