Numerical study of back-propagation suppression and intake loss in an air-breathing pulse detonation engine

Abstract

In order to reduce the back-propagation pressure and the back-propagation distance of burnt gas in the air-breathing pulse detonation engine effectively, two back-propagation suppression structures were proposed in this paper. The influences of channel width (D) and unit length (L) in the corresponding back-propagation suppression structure on the intake loss and the back-propagation characteristics were studied by the 2-D numerical simulation which was based on stoichiometric propane/air mixture to obtain the optimal structure. The grid independence and the reliability of numerical simulation were verified. The simulation results indicated that the back-propagation suppression structure with a flow channel formed by the annular cavities and the convergent sections was the structure with the optimal back-propagation suppression performance. And the following two methods were proved to be effective in this paper. By the means of propagating the pressure wave along the arc-shaped channel, the propagation distance of the pressure wave increased, which resulted in an attenuation of the back-propagation pressure. And the back-propagation pressure was reduced by the way of making the pressure wave propagate toward the downstream of the engine after colliding with the wall of the annular cavity and offsetting with the expansion wave.