Grant-in-Aid for Scientific Research (A).
|Allocation Type||Single-year Grants|
|Research Institution||Tohoku University|
NAKAHASHI Kazuhiro Tohoku University, Graduate school of Engineering, Professor, 大学院・工学研究科, 教授 (00207854)
SAWADA Keisuke Tohoku University, Graduate school of Engineering, Professor, 大学院・工学研究科, 教授 (80226068)
INOUE Osamu Tohoku University, Institute of Fluid Science, Professor, 流体科学研究所, 教授 (00107476)
OBAYASHI Shigeru Tohoku University, Institute of Fluid Science, Associate Professor, 流体科学研究所, 助教授 (80183028)
YAMAMOTO Satoru Tohoku University, Graduate school of Engineering, Associate Professor, 大学院・工学研究科, 助教授 (90192799)
FUKUNAGA Hisao Tohoku University, Graduate school of Engineering, Professor, 大学院・工学研究科, 教授 (50134664)
福西 祐 東北大学, 大学院・工学研究科, 助教授 (60189967)
小濱 泰昭 東北大学, 流体科学研究所, 教授 (60006202)
高山 和喜 東北大学, 流体科学研究所, 教授 (40006193)
|Project Period (FY)
1998 – 2000
Completed(Fiscal Year 2000)
|Budget Amount *help
¥35,200,000 (Direct Cost : ¥35,200,000)
Fiscal Year 2000 : ¥10,000,000 (Direct Cost : ¥10,000,000)
Fiscal Year 1999 : ¥8,800,000 (Direct Cost : ¥8,800,000)
Fiscal Year 1998 : ¥16,400,000 (Direct Cost : ¥16,400,000)
|Keywords||Supersonic transport / Aerodynamics / Optimization / Computational fluid dynamics / Boundary layer transition / Aeroacoustics / 空力弾性|
In this study, aerodynamic problems related to the next generation supersonic transport have been investigated and the following results were obtained.
1. A CFD code based on the unstructured grid to efficiently and accurately evaluate the aerodynamic performance of airplanes was developed. This includes several new schemes such as the surface/volume grid generation methods using the CAD data and the implicit time integration on unstructured grid.
2. The CFD code was applied to evaluate the aerodynamic coefficients of the NAL experimental supersonic airplane in ascent flight. Numerical result revealed the cause of the high lift production during the transonic flight regime.
3. The separation process of the NAL experimental supersonic airplane from the rocket booster was numerically simulated and the aerodynamic coefficients during the separation were obtained by a newly developed overset grid method. This scheme is a promising approach to evaluate the dynamic stability of the airplane as
4. For aerodynamic investigations of the takeoff/landing performance of a supersonic transport, a numerical scheme to predict vortex-dominated flows over delta wings were developed using the adaptive refinement and the vortex-center identification. This scheme was shown to be effective to accurately predict the vortex breakdown at high angle of attack.
5. An inverse design method originally developed for transonic wings was extended to supersonic wings. With this code, the main wing of the NAL experimental supersonic airplane was designed to realize the enlarged natural laminar flow on the upper surface of the wing for improved L/D performance.
6. An efficient adjoint optimization code has been developed using the unstructured grid approach, The resulting code has been used for aerodynamic shape optimization problems of wing alone, wing-fuselage, and wing-fuselage-nacelle configurations, as well as flap angle optimization on the wing-fuselage configuration at transonic cruise.
7. An improved multiobjective genetic algorithm has been developed and applied to the supersonic wing design. Four design objectives were considered : minimizations of aerodynamic drag both at supersonic and transonic cruise conditions as well as minimizations of pitching moment and root-bending moment. The design results indicate that a new type of "arrow wing" configuration has good performances in all design objectives. Less