Experimental and Numerical Investigation on Backpressure in Valueless Air-breathing Pulse Detonation Engine

摘要

Experimental and numerical studies were performed to improve the understanding of backpressure in valueless air-breathing pulse detonation engine (APDE). A two-phase APDE was used with gasoline as fuel and air as oxidizer. It was found in the experiments that the peak value of backpressure almost increased linearly with the operation frequency. The oscillation of the backpressure decreased with the increasing frequency. Numerical investigation on the backpressure was also performed. The numerical result was basically agreed with the experimental result which indicates that the numerical methods adopted in this paper were reasonable. The formation and propagation of the backpressure were analyzed. The effect of block ratio of venturi's throat on backpressure was also numerical investigated. The result showed that a relatively minor block ratio of venturi has little effect on the backpressure for valueless APDE. The time interval that the inlet was exposed to the relatively high pressure disturbance decreased when the block ratio increased to 0. 6. The appropriate block ratio should be optimized through considering both flow resistance and backpressure.