下颌式进气道固冲发动机二次燃烧性能研究

Performance investigation of the secondary combustion for ducted rocket with chin inlet

针对采用下颌式进气道的固体火箭冲压发动机,建立了二次燃烧性能计算模型,对掺混燃烧性能进行了仿真研究。研究表明,采用掺混装置可大幅提升下颌式进气道的固冲发动机补燃室一次燃气和空气的掺混均匀度,并通过数值仿真对掺混装置进行了优化。结合数值仿真优化结果,通过地面直连试验,验证了不采用与采用掺混装置的补燃室二次燃烧性能。试验结果表明,合理设计掺混装置,可显著提高补燃室二次燃烧性能,特征速度燃烧效率均在93%以上;空燃比在6~20之间的发动机高空比冲提升了55%以上,空燃比在20~30之间的发动机高空比冲提升了75%以上。

Computation model was developed for the secondary combustion performance of ducted rocket with chin inlet.The secondary combustion performance was simulated, and the results showed that the mixing homogeneity of the first gas and the air in the dueted rocket combustion could be improved with mixing device. The configuration of the mixing device was optimized through simulation investigation.The mixing and combustion performance with and without mixing device were compared through the direct- connect experiments based on the configuration optimization. The secondary combustion performance could be increased with optimized mixing device.The combustion efficiency at a characteristic velocity was above 93%. The engine impulse at high altitude was improved hy 55% with the air/fuel ratio between 6 and 20, and it was improved by 75% with the air/fuel ratio between 20 and 30.