Experimental study on propagation, quenching, and re-initiation characteristics of rotating detonation wave with liquid kerosene–oxygen-enriched air

Abstract

In a rotating detonation engine (RDE), specifically a low-activity liquid fuel RDE, ensuring the continuous and stable propagation of detonation waves is important. In the RDE experiment with oxygen-enriched air as the oxidant and liquid kerosene as the fuel at room temperature, the stability of the rotating detonation wave (RDW) is found to be extremely inadequate. This inadequacy is manifested by more than 10 times of quenching and re-initiation within 500 ms. This frequent quenching and re-initiation phenomena considerably differ from those of the gaseous fuel RDE. Consequently, the velocity deficit of the detonation wave increased and the propulsion performance of the RDE was affected. In a further study using pressure sensors and high-speed cameras, the quenching phenomenon was found to be related to the supply state of the propellant, and the re-initiation phenomenon was related to the chemical reaction zone in the combustion chamber. To verify the foregoing, a special control test was performed. After improving the supply state of the corresponding propellant, the unstable characteristic of liquid fuel was effectively suppressed and a stable RDW with a velocity of 1321 m/s was obtained. The results of this study reveal the mechanism of liquid fuel quenching and re-initiation. This mechanism significantly restrains the instability of liquid fuel detonation waves.