표제지
초록
Abstract
목차
제1장 서론 13
제2장 관련 이론 15
2.1. 공력 가열(Aerodynamic Heating) 15
2.1.1. 에커트 기준 온도 기법(Eckert Reference Temperature Method) 17
2.2. 근사적 해석 기법을 통한 공력-열 환경 해석 20
2.2.1. 방사 기저 함수 보간 (Radial Basis Function Interpolation) 21
2.2.2. 유선 모델링(Streamline Modeling) 23
2.2.3. Modified Newtonian Flow 25
2.2.4. Oblique shock 26
2.2.5. Tangent-Cone Empirical Method 31
2.2.6. Prandtl-Meyer Expansion 34
2.2.7. Shock-Expansion 37
2.2.8. Second-Order Shock Expansion Method 37
2.3. 공력 축약 모델 (Reduced Order Aerodynamic Model) 39
2.3.1. 크리깅 기법 (Kriging Method) 39
2.3.2. 3차원 오일러 전산 유체 해석 41
제3장 연구 내용 45
3.1. 유동 해석 방법론 연구 45
3.1.1. 근사적 해석 기법을 이용한 유동 해석 정확성 검토 45
3.1.2. 전산 유체 해석을 이용한 유동 해석 50
3.2. 공력 축약 모델 구성 및 검증 54
3.2.1. 공력 축약 모델(ROAM) 구성 54
3.2.2. 비실측점 예측을 통한 공력 축약 모델 검증 56
3.3. 공력-열 연계 열전달 해석 59
3.3.1. 유한 요소 모델링 59
3.3.2. 공력 열 하중 요소 62
3.4. 경로 의존적 열구조 해석 64
3.4.1. 비행 경로를 고려한 자유 경계 조건 64
3.4.2. 경로 의존적 열구조 해석 68
3.5. 해석 결과 및 비교 68
3.5.1. 공력-열 연계 열전달 해석 결과 68
3.5.2. 경로 의존적 열구조 해석 결과 74
제4장 결론 80
참고 문헌 82
Table 1. Description of Method for Approximate Flow Analysis 20
Table 2. Types of Radial Basis Function 22
Table 3. Freestream Condition for Approximate Flow Analysis 47
Table 4. Methods for Comparison of Approximate Flow Analysis 48
Table 5. Flight Condition : X-43A Trajectory 49 sec 52
Table 6. Flight Conditions for Validation of ROAM 57
Table 7. Mass Profile of FEM Model 65
Figure 1. Scheme of Velocity and Temperature profile in Hypersonic Boundary Layer 15
Figure 2. Scheme of Impact Region / Shadow Region 21
Figure 3. Geometric Configuration of Oblique Shock 27
Figure 4. Geometric Figuration of Flow by Expansion Wave 34
Figure 5. Angle of Mach Wave 35
Figure 6. Second-Order Shock Expansion Method 38
Figure 7. Example of Kriging Model 41
Figure 8. Algorithm of Approximate Flow Analysis Method 45
Figure 9. Ogive Model and Mesh for Approximate Flow Analysis 47
Figure 10. Temperature Comparison : Shock-Expansion 48
Figure 11. Temperature Comparison : Tangent-Cone Empirical Method 48
Figure 12. Temperature Comparison : SE - TCE Combination 49
Figure 13. Temperature Comparison : Second-Order Shock Expansion Method 49
Figure 14. Subject Modeling: Hypersonic Aircraft X-43A 50
Figure 15. Cross-Sectional Mesh Configuration of Computational Fluid Dynamic Analysis 51
Figure 16. CFD Result Cross-Sectional Distribution, Mach Number 52
Figure 17. CFD Result Cross-Sectional Distribution, Temperature 53
Figure 18. CFD Result Cross-Sectional Distribution, Pressure 53
Figure 19. Flight Conditions Sampling for Reduce Order Aerodynamic Model 54
Figure 20. Data Flow of CFD Result for Reduced Order Aerodynamic Model 56
Figure 21. ROAM Validation : Mach Number 57
Figure 22. ROAM Validation : Temperature 58
Figure 23. ROAM Validation : Pressure 59
Figure 24. X-43A FEM Model Configuration 60
Figure 25. Material Profiles 60
Figure 26. Configuration of Finite Element Model 61
Figure 27. Aerodynamic-Thermal Load Element 63
Figure 28. Surface Sets for User Element 63
Figure 29. Reaction Force and Moment by Distributed Pressure Load in 2D 64
Figure 30. Procedure for Free Boundary Condition 66
Figure 31. Reference Point at Center of Mass & Rigid Body Constraint 67
Figure 32. A/T Heat Transfer Analysis Result : Temperature at Trajectory 150 sec 69
Figure 33. A/T Heat Transfer Analysis Result : Control Surface Tempature at Trajectory 150 sec 70
Figure 34. Location of Thermocouple : Nose 70
Figure 35. Comparison of Temperature History : Nose 71
Figure 36. Location of Thermocouple : Control Surface 72
Figure 37. Comparison of Temperature History : Upper Surface 72
Figure 38. Comparison of Temperature History : Lower Surface 73
Figure 39. Thermal-Structural Analysis Result, Analysis Model A : Stress at Trajectory 150 sec 74
Figure 40. Thermal-Structural Analysis Result, Analysis Model B : Stress at Trajectory 150 sec 75
Figure 41. Thermal-Structural Analysis Result, Analysis Model A : Interior Structure Stress at Trajectory 150 sec 76
Figure 42. Thermal-Structural Analysis Result, Analysis Model B : Interior Structure Stress at Trajectory 150 sec 76
Figure 43. Thermal-Structural Analysis Result, Analysis Model A : Plastic Strain at Trajectory 150 sec 77
Figure 44. Thermal-Structural Analysis Result, Analysis Model B : Plastic Strain at Trajectory 150 sec 77
Figure 45. Temperature Comparison : Engine Internal Structure 78
Figure 46. Thermal-Structural Analysis Result, Analysis Model A : Pressure Load Only 79