中心锥喷管喉道比参数对旋转爆轰燃烧影响的数值研究

The propulsion performance of the rotating detonation engine（RDE）is related to the design of the back nozzle. In order to explore how the structure of the aerospike nozzle affects the combustion mode of rotating detonation wave and the propulsion performance of rotating detonation engine，the three-dimensional（3D）Euler equations coupled with hydrogen/air detailed mechanism is used as the governing equations and the rotating detonation engines with nozzles of different throat ratio have been simulated. The numerical results show that with the decreasing of the nozzle throat ratio parameter，the rotating detonation wave in chamber presents a stable single-wave combustion mode，a chaotic combustion mode with alternating single and double waves and a deflagration combustion mode in turn. It can be found that the reflected shock wave generated at the throat of nozzle is the key factor affecting the combustion mode. With the decreasing of throat ratio parameters，the intensities of the reflected shock wave increase gradually and a local hot spot is caused by mixing with fresh air flow，which is leading that combustion modes change from single-wave mode to the chaotic combustion mode in RDE. As the throat ratio further decreases，the pressures of reflected shock waves are higher，leading that the detonation waves in the chamber quench and the combustion mode changes to deflagration combustion. Through the analyses of the propulsion performance with different throat ratio parameters，it can be found that the thrust of RDE increases with the decreasing of the throat ratio，and the thrust in the single-wave combustion mode is better than that of the chaotic mode and the deflagration mode.