Abstract: In order to study the effects of different combustion chamber length on the thrust and specific impulse of rotating detonation engine，the RDE thrust test bed is designed. RDE whose annular combustion chamber inside and outside diameter was 70 mm and 80 mm respectively was used as the experimental models，which based on the slot-injector impinging injection method. Using H2 and Air as fuel and oxidant respectively，being ignited by the high-energy spark plugs directly and using piezoelectric force transducer measuring thrust，the work performance of the engine was studied whose combustion chamber length was 40 mm，60 mm，90 mm and 120mm respectively. Research show that the change of combustion chamber length has a great influence on RDE stability work scope. Within the scope，detonation wave propagation velocity，thrust and specific impulse of RDE all increase gradually with the increase of inlet mass flow. Detonation wave propagation velocity，thrust and specific impulse of RDE all reach maximum when equivalence ratio or combustion chamber length reach an optimal value. For RDE experimental model in this paper，specific impulse based on the mixture could reach 74.61s.

Key words: Rotating detonation wave；Separated injection；Combustion chamber length；Working-condition range；Thrust and specific impulse

摘要： 为了研究燃烧室长度对旋转爆震发动机(RDE)推力和比冲的影响，设计了RDE推力试验台，以环形燃烧室内径和外径分别为70mm和80mm的RDE作为实验模型，发动机采用环缝-喷孔对撞式掺混方式，以H2和Air分别作为燃料和氧化剂，使用高能火花塞直接点火，并用压电式力传感器测量推力，实验研究燃烧室长度分别为40mm，60mm，90mm和120mm的发动机工作性能。通过实验发现，燃烧室长度对RDE稳定工作的工况范围有很大的影响；在稳定工作的工况范围内，燃烧室内的爆震波的传播速度及RDE的推力和比冲随着入口质量流量的增大而逐渐提高，而当量比和燃烧室长度均存在一个最佳值，使爆震波的传播速度及RDE的推力和比冲达到最大值。针对于本论文中的RDE实验模型，基于混合物的比冲最高能够达到74.61s。

关键词: 旋转爆震；分开喷注；燃烧室长度；工况范围；推力和比冲