高超声速高焓流动转捩模式研究

准确预测由层流向湍流的转捩过程是高超声速飞行器设计的重点和难点之一。未来高超声速飞行将向大空域和更宽马赫数范围发展，高雷诺数和高焓来流使得机体表面流动转捩过程与高温真实气体效应深度耦合。而对于高超声速高焓流动转捩机理与预测问题，国内尚无相关技术积累，国外也未见任何研究发表。因此，本课题拟根据线性/非线性流动稳定性理论与自适应化学反应机理，结合现代计算流体力学技术，首先发展高效高精度的数值模拟方法，获得高超声速高焓基本流场；进而揭示流动失稳机理，归纳出高温真实气体效应对流动转捩的影响规律；在此基础上，建立相应的适用于大规模并行计算的湍流/转捩模式，为中低空新型高超声速飞行器的设计和改进提供理论依据和技术支持。

Predicting laminar-turbulent transition in hypersonic boundary layers plays a key role in the design of future space vehicles operating at sustained hypersonic speeds. The future hypersonic flight in a wide range of both altitudes and Mach numbers, results in high-enthalpy hypersonic flows, at high Reynolds number, around the vehicle surfaces. So far, there haven’t been published any investigations into the real gas effect upon high-enthalpy hypersonic flow transition. Therefore, based on the linear/nonlinear stability theories and the adaptive chemical reaction mechanism, in combination with modern CFD methods, this work is firstly to develop numerical methods of high fidelity and efficiency, to resolve the mean high-enthalpy hypersonic flow-field. Then, stability analysis is to be carried out to understand the instability/transition mechanism in such flows. Consequently, a new transition/turbulence model will be proposed and validated in this study that considers the real gas effect in hypersonic flows, which could be used for the design of future space vehicles operating at medium/minimum altitude.