射流对高超声速进气道起动性能的影响

为探索利用射流技术降低进气道起动马赫数的可行性,对二元高超声速进气道二维流场进行了数值模拟,通过对比不同工况的流场结构、流量系数及总压恢复系数,分析了射流对高超声速进气道的作用效果,并研究了射流速度、压强及倾角对进气道起动性能的影响。分析结果表明:施加射流,激波与进气道边界层原有干扰形式发生改变,是降低进气道起动马赫数的主要原因。研究还表明,增大射流速度利于提高控制效果,但持续增大射流速度,会造成隔离段反压升高,并且这一现象与射流压强相关,降低射流压强能使进气道起动的射流速度区间扩大,同时在不同射流倾角下,上述规律表现一致。该研究揭示了进气道起动能力随射流参数变化的系统性规律,可用于指导工程设计及优化。

Effect of injection on starting characteristics of hypersonic inlet

In order to explore the feasibility of using injection technology to reduce the start Mach number of hypersonic inlet,the flow field of the two-dimensional hypersonic inlet was calculated by numerical simula-tion. The effect of injection on the hypersonic inlet was analyzed by comparing the flow field structure,mass-captured coefficient and total pressure recovery coefficient under different working conditions,and the influ-ence of jet velocity,pressure and angle of inclination on starting performance of the inlet was also studied. The analysis results show that the change of original interference form of the shock wave and inlet boundary-layer is the main reason for the reduction of the start Mach number of inlet. The study also shows that increasing jet velocity is conducive to improving the control effect,but increasing jet velocity continuously would result in an increase in the back pressure of the isolation section. This phenomenon is related to the jet pressure,and re-ducing the jet pressure could expand the effective jet velocity range to start the inlet. At different jet angles of inclination,the above rules are consistent. The simulation results reveal the systematic rule of changes of the in-let starting ability with injection parameters,which can be used to guide engineering design and optimization.