引射模态总压比对气动壅塞影响

Effects of Total Pressure Ratio on Fabri Choking in Ejector Mode

为了提高引射模态火箭射流引射抽吸能力和发动机性能,利用全流道一体化数值模拟方法,针对马赫数为0.8飞行状态,研究了主次流总压比对引射空气流量、气动壅塞的影响规律,结果表明:在低总压比条件下,提高主次流总压比,可提高火箭射流的引射抽吸能力,引射空气流量增大;随着总压比的进一步提高,欠膨胀的火箭射流超声速势核区会挤压引射空气流道,冲压燃烧室反压前传导致引射空气流量降低;主次流总压比高于350,火箭射流会将引射空气流道堵塞,产生气动壅塞,引射空气流量降低为零。在一定范围内,提高主次流总压比有利于提高引射模态发动机性能。

In order to improve the ejection capacity and engine performance,the whole flow-path CFD simulation method was used.Under the subsonic flight condition of Ma=0.8,the effects of total pressure ratio of primary and secondary flows on Fabri choking and ejection capacity were studied then.The results show that with a low total pressure ratio,the increase of the total pressure ratio of primary and secondary flows can increase both the primary rocket jet ejection capacity and ejection air mass flow rate.The higher pressure primary rocket jet expands in the ramjet combustor and squirt the secondary ejection air flow path,therefore reduces the ejection air mass flow rate.The primary rocket jet blocks the secondary ejection air flow path,resulting in pneumatic congestion,therefore the secondary ejection air mass flow reduces to 0,when the total pressure ratio is higher than 350.Within a certain range,increasing the total pressure ratio is beneficial to improve the engine performance of the ejector mode.