Research On The Flow Characteristics Of The Inlet For Air-breathing Pulse Detonation Engine

It is of great importance for the inlet to work normally and efficiently as it is one of the crucialaerodynamical components for the pulse detonation engine. However, the flow mechanism of the inletis quite complicated since the high detonation-induced pressure in the combustor will propagateupstream and then make an unsteady interference to the flowfield of the inlet. Hence, it is necessary tomake a further study on the flow characteristics of typicl inlets under oscillatory detonation-inducedpressure, so as to evaluate the applicability of the inlets for the pulse detonation engine as well asmake an attempt to improve the design of the inlet.Firstly, this thesis numerically studies the unsteady flowfield of a valveless supersonic inlet coupledwith a pulse detonation engine combustor. The flow structure of the inlet which is interfered by thedetonation wave and its reflected shock is obtained, and a comparison on the performances among thethree models used different coupled methods is made. Then, a subsonic inlet for pulse detonationengine with aerodynamic valve is numerically and experimentally studied to obtain its flow structureand performance characteristics on both cold flow and ignited conditions. Influence on the flowcharacteristics exerted by different inlet structures or by the detonation waves with various amplitudesand frequencies is numerically studied as well. Results indicate that the aerodynamic valve cannotbaffle the detonation-induced pressure effectively, so the violent backpressure perturbation propagatesupstream and passes through the aerodynamic valve rapidly, resulting in a high speed reverse flow inthe entire entrance of the inlet. It is also found that the reverse flow strengthens by increasing theamplitude of the detonation pressure, but first weakens before growing again when raising thedetonation frequency. Finally, since both the vaveless inlet and aerodynamic vavled inlet are unable toweakening the high detonation pressure significantly, a new style pulse detonation engine with singletube, rotate valve and double culverts is designed and the flowfield of the inlet is numerically studied.Results show that such an inlet is simple structured, reliable and it can satisfy the flow capturerequirement of the engine as well as avoid the interference generated by the multi-tubes whencompared with the multi-tube, rotate valve pulse detonation engine.