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

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