Generation mechanism of a new type of unburnt gas pocket and its influences on the detonation-wave/boundary-layer interaction

Abstract

This work studies numerically the generation mechanism of a new type of unburnt gas pocket and its effects on the characteristics of detonation-wave/boundary-layer interaction in supersonic flows. Results show that this new type of unburnt pocket is generated due to a local re-ignition of preheated gas behind the separated oblique shocks, unlike the traditional unburnt pockets generated due to the longitudinal instability of the detonation front. The chemical energy released by the new unburnt pocket in the supersonic area is found to be blocked by the shear layer and is unfavorable for the self-sustaining propagation of the detonation wave.