塞式喷管对旋转爆震起爆、传播与推进特性的影响

Experimental investigations have been carried out to clarify the influence of the aerospike nozzle on the ignition process，wave propagation and propulsive performance of rotating detonations. Ethylene and an oxygen-nitrogen mixture with an oxygen volume fraction of 50% are employed as fuel and oxidizer，respectively. It has been observed that five propagation modes have appeared in the combustion chamber with an aerospike nozzle，among which the peak pressures oscillate periodically in both the self-adjustive mode and the periodic oscillation mode. A steady propagating wave can be obtained immediately after the ignition in nozzle-less cases，while the peak pressure oscillates in the ignition process in the single-wave mode after a nozzle is added. Compared with the nozzle-less cases，the propulsive performance has been improved distinctly by 101.9%. The static pressure and thrust will be slightly reduced after the transition in the self-adjustive mode，and the thrust reduces by 7.6%. However，the periodic oscillations of the peak pressure will increase the unstable characteristics，which should be avoided.