표제지
초록
Abstract
목차
제1장 서론 11
1.1. 연구 배경 11
1.2. 연구 내용 및 목적 13
제2장 본론 15
2.1. 지배방정식 15
2.1.1. 가상 압축성 기법 적용 Navier-Stokes 방정식 19
2.2. 2-equation 난류 모델 22
2.2.1. k-ω SST 모델 22
2.3. 무차원화 24
2.4. 수치해석 기법 26
2.4.1. 준 이산화 방정식 26
2.4.2. Roe의 근사 리만 해법 28
2.4.3. MUSCL extrapolation 36
2.4.4. 점성항의 이산화 36
2.4.5. 시간 전진법 38
2.4.6. 경계 조건 41
제3장 수치해석 결과 43
3.1. 비점성(inviscid) 유동 44
3.1.1. NACA0012 익형(airfoil) 주위 유동 44
3.2. 층류(laminar) 유동 48
3.2.1. 원형 실린더(cylinder) 주위 유동 48
3.3. 난류(turbulent) 유동 52
3.3.1. 평판(flat plate) 유동 52
3.3.2. 범프(bump) 유동 58
3.3.3. 3D 범프(bump) 유동 62
제4장 결론 및 향후 과제 67
참고 문헌 69
Table 1. Compare drag coefficient 51
Figure 1. Auxiliary cell 37
Figure 2. 257 x 65 grid for NACA0012 44
Figure 3. Surface pressure coefficient of NACA0012 46
Figure 4. Convergence histories for NACA0012 problem 46
Figure 5. Surface pressure coefficient of NACA0012 47
Figure 6. Convergence histories for NACA0012 problem 47
Figure 7. 257 x 257 grid for circular cylinder 48
Figure 8. Streamlines around circular cylinder 50
Figure 9. Surface pressure coefficient distribution of circular cylinder 50
Figure 10. Convergence histories for circular cylinder problem 51
Figure 11. 273 x 193 grid for a flat plate 52
Figure 12. Boundary conditions for a flat plate grid system 53
Figure 13. Surface skin friction coefficient of a flat plate 55
Figure 14. Velocity profile at x=0.97(red) & x=1.9(blue) 55
Figure 15. Turbulent viscosity coefficient contour of a flat plate 56
Figure 16. Turbulent viscosity coefficient distribution at x=0.97 56
Figure 17. Convergence histories for a flat plate problem 57
Figure 18. 353 x 175 grid for a bump 58
Figure 19. Boundary conditions for a bump grid system 59
Figure 20. Surface pressure coefficient of a bump 60
Figure 21. Surface skin friction coefficient of a bump 60
Figure 22. Turbulent viscosity coefficient contour of a bump 60
Figure 23. Convergence histories for a bump problem 61
Figure 24. 353 x 33 x 161 grid system for 3D bump 62
Figure 25. Pressure coefficient distribution of 3D bump 64
Figure 26. Turbulent viscosity coefficient contours at x=-0.3 65
Figure 27. Turbulent viscosity coefficient contours at x=-1.2 65
Figure 28. Convergence histories for 3D bump problem 66