Influence of viscous boundary layer on initiation zone structure of two-dimensional oblique detonation wave

The influence of the viscous boundary layer on the oblique detonation wave structure has been simulated and analyzed by solving the two-dimensional Navier–Stokes equations containing the hydrogen/air elementary reaction model. It is found that the effect of the viscous boundary layer can be neglected in the smooth transition initiation structure, but not in the abrupt transition initiation structure. The interaction of the lateral shock wave and the viscous boundary layer results in the formation of a high-temperature recirculation zone near the wall of the initiation zone, a novel structure that does not appear in inviscid formulations. Within this structure, the chemical reaction is triggered to occur in advance, eventually leading to the equilibrium initiation position relocating upstream compared with the inviscid case. Nevertheless, the viscous boundary layer has a limited impact on the main flow region downstream of the oblique detonation. The shock wave structures and pressure distributions at various Mach numbers are obtained computationally and analyzed in detail.