尖锐前缘气动加热机理与激波脱体距离研究

针对尖锐前缘所处的气动环境,分析了由于前缘尖化所带来的稀薄效应影响。应用理论方法推导了尖锐前缘驻点气动热的计算方法和计算公式,并结合CFD方法、DSMC方法和Fay-Riddel工程方法对其前缘钝头的流场、驻点热流进行了计算和对比分析。计算结果表明,由于前缘的尖化使得稀薄气体效应提前出现,从而影响到前缘的激波厚度、激波形状和激波脱体距离等流动现象,导致激波结构复杂化,可能会对进气道唇口的斜激波带来不利的影响。另外稀薄效应的影响降低了驻点热流,缓解了尖化前缘的气动热环境。

Numerical study of aerodynamic heating and shock detached distance for sharp leading edge

Considering the special aerodynamic environment on the sharp leading edge,numerical study is carried out to illustrate the rarefied effect influence.Combined with CFD method,DSMC method and Fay-Riddell method,the stagnation point heat flux and local flow field around the edge are investigated.The simulation result shows that the early rarefied effect caused by edge must be considered in simulation,even though it releases the aerodynamic heating effectively.Moreover,the shock thickness and shock detached distance experience with great change when the Kn number is modified.The complex shock wave structure behind the cowl lip of the inlet will probably have an influence on the inlet efficiency of the vehicle.