流体喷管对脉冲爆震发动机推进性能的影响

Impact of fluidic nozzle on propulsion performance of pulse detonation engine

为了进一步提高脉冲爆震发动机(PDE)的推进性能,对PDE使用流体喷管模型进行了多循环数值模拟研究,并提出了主次流错相位喷注方案。结果表明:主次流错相位喷注方案不仅可以调节主流和二次流的有效流通面积,改善喷管的非设计点状态,而且可以提高爆震室内可燃气最终充填压力,增强爆震燃烧强度;在主次流错相位喷注方案下,喷管主流进口瞬时气流总压相对喷管设计点的离散程度明显下降,有效改善了喷管的非设计点状态;最佳的主次流相位差为反传压缩波恰好传播至爆震室头部这一工况,最佳的二次流喷注位置为喷管喉部;相比基准喷管的最大比冲性能,PDE使用流体喷管可以产生5.64%的比冲增益。

In order to further improve the propulsion performance of the pulse detonation engine(PDE),a multi-cycle numerical simulation was carried out for the PDE with fluidic nozzle,and a scheme of alternating phase injection of the main and secondary flows was proposed.According to the computational results,the new nozzle design can adjust the effective flow area of the main and secondary flows,thereby improving the off-design point state of the nozzle.Furthermore,it can increase the actual filling pressure of combustible gas,thereby enhancing the detonation combustion intensity.Also,the best phase difference between the main and secondary flows manifested the condition that the back compression wave just propagated to the head of detonation chamber.The best injection position of secondary flow was the nozzle throat.As compared with the maximum specific impulse generated by baseline nozzle,the pulse detonation engine with fluidic nozzle could produce a specific impulse gain of 5.64%.