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Aerodynamic Research for the Next Generation Supersonic Transport

下一代超音速运输机的空气动力学研究

基本信息

批准号：
10305071
负责人：
NAKAHASHI Kazuhiro
金额：
$ 22.53万
依托单位：
Tohoku University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (A).
财政年份：
1998
资助国家：
日本
起止时间：
1998 至 2000
项目状态：
已结题

项目摘要

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 … More well.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

本文对新一代超声速运输机的气动问题进行了研究，得到了以下结果：为了高效、准确地评估飞机气动性能，开发了基于非结构网格的CFD程序。其中包括基于CAD数据的面/体网格生成方法和基于非结构化网格的隐式时间积分等新方案。应用CFD程序对NAL实验超声速飞机爬升飞行的气动系数进行了计算。数值结果揭示了跨声速飞行过程中产生高升力的原因。对NAL实验超声速飞机与火箭助推器的分离过程进行了数值模拟，并采用一种新提出的叠置网格法计算了分离过程中的气动系数。该方案是一种很有前途的评估飞机动态稳定性的方法。为研究超声速运输机的起降性能，采用自适应细化和涡中心识别的方法，建立了三角翼涡主导流预测的数值格式。结果表明，该方案能够准确预测大迎角涡击穿。最初为跨声速机翼开发的反设计方法被推广到超声速机翼。利用该代码对NAL实验超声速飞机主翼进行了设计，实现了机翼上表面自然层流的扩大，提高了L/D性能。利用非结构化网格方法开发了一种有效的伴随优化代码，所得到的代码已用于单翼、翼-机身和翼-机身-机舱构型的气动形状优化问题，以及跨音速巡航时翼-机身构型的襟翼角优化。提出了一种改进的多目标遗传算法，并将其应用于超音速机翼设计中。考虑了四个设计目标：在超音速和跨音速巡航条件下最小化气动阻力，以及最小化俯仰力矩和根部弯矩。设计结果表明，一种新型“箭翼”构型在各设计指标上均具有良好的性能。少