高超声速飞行器高温流场数值模拟面临的问题

随着高超声速飞行器目标光辐射和电磁散射特性研究的发展和深入,高温流场特性日益引起人们的关注。由于高温流场特性研究中涉及到非常多的复杂气动现象,如气动加热、烧蚀、辐射、燃烧、化学反应以及湍流等,因此其数值模拟面临着诸多挑战。这里基于连续流计算流体力学(CFD)技术和稀薄气体蒙特卡罗直接仿真(DSMC)方法,从化学物理模型建模、方法稳定性与数值求解效率出发,分析了高超声速飞行器外部绕流、尾迹和发动机喷焰三方面的流场特性数值模拟在不同弹道、热防护手段和飞行流域环境下所面临的问题。在此基础上提出了数值求解技术和化学物理模型建模今后需要发展的方向,为有效提高高超声速高温流场特性数值模拟效率、增加流场特性预测精度提供了指导,从而为研究流场对高超声速飞行器目标光辐射和电磁散射特性影响提供有效的基础数据。

Problems of numerical simulation of high-temperature gas flow fields for hypersonic vehicles

With the development of research on optical radiative characteristics and electromagnetic scattering of hypersonic vehicle, more and more attention has been paid to the properties of high-temperature gas flow fields. A large amount of aerodynamic phenomena are involved in the study of the properties of high-temperature gas flow fields such as aeroheating, ablation, radiation, combustion, chemical reaction, turbulence, etc., which makes the numerical simulation approach face all kinds of challenges. Based on the computational fluid dynamic (CFD) and direct simulation Monte-Carlo (DSMC) methods, the problems associated with chemical and physical model, method stability and computational efficiency are considered when solving external flow, wake and engine exhaust plume for general hypersonic vehicles at different trajectories, thermal protection and flow regime conditions. The corresponding future research areas are proposed involving numerical technique and chemical and physical model, which will effectively improve numerical effects and increase predicting precision. As a result, the available basic data needed for investigating the influence of flow properties on optical radiative characteristics and electromagnetic scattering of hypersonic vehicle can be supplied.