真实气体效应对Ma10级进气道流动的影响

Real-Gas Effects on Hypersonic Inlet Flow at Mach 10

为了探究高马赫数超燃冲压发动机高速飞行时真实气体效应对进气道流场的影响,仿真获得了不同气体模型下Ma10级进气道流场结构和性能。结果表明:进气道主流流场温度较低,不足以触发空气的离解反应,反应仅发生在边界层内,但反应程度较低,远未达到化学平衡状态,除了边界层温度及热载荷特性,其流场结果则更为贴近冻结流流场,因而化学非平衡模型与热完全气体模型的进气道通流流场结构和性能基本一致。而真实气体效应导致边界层特性的不同,对进气道起动特性产生影响,吸热离解反应通过对进口分离包的抑制和增大进口马赫数将进气道的再起动马赫数从9.8降低到9.4。在对进气道在宽速域应用中的钝化设计研究发现,真实气体效应虽然对前缘钝化进气道流场的压力分布和性能无明显影响,但是其能起到整体降低壁面热流的作用,不仅钝头处的热流降低了1MW/m2,通道内的热流也整体降低了0.1MW/m2。

A simulation study of a rectangular hypersonic inlet in different gas model has been proposed toenrich the understanding of the real-gas effect on the inlet flow pattern while the high speed scramjet flies at theMach 10.The results show that the air dissociation reaction can only be found in the boundary layer while the main-stream temperature is not high enough to trigger the chemical reaction.Because the low reaction degree in theboundary layer is far from the chemical equilibrium state,the flow pattern and characteristics of the inlet with chem-ical non-equilibrium gas model are basically identical with the results of the thermally perfect gas model which rep-resents the frozen flow,except the temperature and heat load in the boundary layer.Besides,the endothermic reac-tion in the boundary layer makes the inlet restarting Mach number decrease from 9.8 to 9.4 by inhibiting the en-trance separation bubble and increasing the entrance Mach number.Furthermore,a study of real gas effect on theinlet wide speed range characteristics,such as the leading-edge bluntness flow pattern,is carried out.And it isfound that the real-gas effect has no significant effect on the pressure distribution and inlet characteristics with theleading-edge bluntness.However,the bluntness can decrease the heat load distribution of the inlet,while the heatload around the leading edge and in the inlet duct decreases by 1 MW/m2 and 0.1 MW/m2,respectively.