Numerical study on wave configuration of wedge-induced oblique detonation wave: Reactive boundary layer effect

Abstract

A numerical simulation solving the Reynolds-averaged Navier–Stokes equation is presented to investigate the initiation and evolution of the wedge-induced oblique detonation wave (ODW) with emphasis on the effects of the burning boundary layer. The nondimensional activation energy ( Ea) is selected as the bifurcate parameter, which varies from 30 to 50. The largest induction ignition length behind the oblique shock/detonation wave is shown to be proportional to the Ea. The initiation of ODW can be attributed to the collision and diffraction of reactive waves. The wave configuration, a series of compression waves (or shock wave), is observed at the conjunction point of the burning boundary layer and combustion wave, which intensifies the pressure jump as increasing the Ea. The polar line analysis demonstrates that the pressure jump triggers the transition from regular reflection to Mach reflection near triple-point. The oscillations of the ODW wave structures, for example, the triple-point and Mach stem, can be attributed to the Rayleigh–Taylor instabilities developed on the reaction front of the boundary layer, which shall be appropriately suppressed to remain the steadiness of the ODW and flow configuration.