扩张型双喉道喷管存在起动问题,使喷管推力性能显著下降。为此,提出了扩张段注气解决喷管起动问题的方案,并利用数值模拟方法,针对二元扩张型双喉道喷管,研究了扩张段注气压比、注气位置等对喷管流动和性能的影响。研究结果表明:扩张段注气可以产生斜激波系和大的分离区,改变了扩张型双喉道喷管主气流通道的形状,减小了激波损失,解决了喷管的起动问题,并使喷管性能显著提高;注气缝位于扩张段中间时,容易形成连续扩张的主流通道,有利于主流的加速和产生推力,因此其推力性能最好。 There is a start-up problem for the dilated double throat lances, which leads to a significant drop in the nozzle thrust performance. For this reason, the scheme of injecting gas in expansion section to solve nozzle starting problem is put forward. By using numerical simulation method, for dual expansion twin throat lance, the effects of injection pressure ratio and gas injection position on nozzle flow And the impact of performance. The results show that the gas injection in the expansion zone can produce oblique shock system and large separation zone, change the shape of the main airflow passage of the expansion type double throat nozzle, reduce the shock loss, solve the starting problem of the nozzle, And the performance of the nozzle is significantly improved. When the air injection slot is located in the middle of the expansion section, it is easy to form the main channel for continuous expansion, which is favorable for acceleration and thrust generation in the mainstream and therefore has the best thrust performance.