Abstract: To investigate the performance of scramjet with multi-staged injection，based on a dual-struts combustor，the combustion phenomenon，heat release law and internal thrust of the engine experimentally with varying equivalence ratio were studied. Mach number and total temperature of chamber inlet were 2 and 1436K，respectively. The mass flow rate of kerosene changed at rate of 11.97g/s2 and 35.90g/s2，respectively. Experiments show that different varying rate of equivalence ratio make no difference to the results. As equivalence ratio at the upstream decreased，upstream flame transformed from full of the tail behind strut into a branch near the shear layer gradually. There are two steady combustion states in experiments: upstream combustion and downstream combustion. As for upstream combustion，change of equivalence ratio at downstream had no significant influence on internal thrust when keeping equivalence ratio at upstream unchanged，while the combustor performance could be improved with more kerosene injected from upstream for downstream combustion state. At upstream equivalence ratio 0.19，the upstream combustion turns into the downstream combustion. Internal thrust of the engine could be enhanced with higher equivalence ratio at the upstream on the condition of upstream combustion when keeping the total equivalence ratio unchanged.

Key words: Scramjet；Combustor；Staged injections；Combustion；Internal thrust

摘要： 为研究超燃冲压发动机分级喷注的性能特点，基于双支板燃烧室开展变当量比喷注下的燃烧现象、释热规律以及发动机内推力性能试验研究。燃烧室入口马赫数2，总温1436K。煤油流量的调节速率分别为11.97g/s2和35.90g/s2。不同当量比调节速率的试验表明，当量比调节速率不影响试验结果。随着上游当量比的减小，上游火焰由充满支板尾部逐渐转变为在剪切层附近分叉。试验中发现，燃烧室存在两种稳定的燃烧状态:上游燃烧状态和下游燃烧状态。上游燃烧状态下，上游当量比相同而下游当量比不同时，燃烧室内推力差别不显著；下游燃烧状态下，增加上游喷注会提高燃烧室性能。上游燃烧状态变化到下游燃烧状态的上游当量比为0.19。在相同总当量比下，上游多分配当量比获得的上游燃烧状态可使内推力增加。

关键词: 超燃冲压发动机；燃烧室；分级喷注；燃烧；内推力