Investigation on propagation of back-pressure in air-breathing pulse detonation engine

With gasoline as fuel and air as oxidizer, experiments were performed to investigate the propagation of back-pressure in an air-breathing pulse detonation engine (PDE) with inner diameter 60 mm. The back-pressure was measured at different operation frequencies ranging from 10 Hz to 30 Hz. The experimental results show that the back-pressure approximately increases linearly with increasing frequency. The ratio that the time of pressure fluctuation to a cycle time increases with increasing frequency. The pressure oscillation has a maximum value with operation frequency of 20 Hz. The numerical model was developed and the characteristic of formation and propagation of the back-pressure was numerically investigated. The simulation results confirm that the back-pressure is induced by the retonation wave. The experimental and numerical results agree well, indicating that the method of simulation can reasonably reflect the propagation process of back-pressure.