Wedge-induced oblique detonation waves in supersonic kerosene-air premixing flows with oscillating pressure

The oblique detonation wave (ODW) induced by a wedge in the supersonic pre-evaporated kerosene-air flow is investigated via the numerical simulation based on the Navier-Stokes equations with a two-step reaction model. The unsteady inflow feature is subject to a continuous sinusoid pressure disturbance. The influence of oscillating amplitudes and disturbance cycle numbers of the unsteady pressure on the stabilization of wedge-induced ODW is analyzed. Based on a smooth transition with a curved shock from the shock-induced deflagration to oblique detonation, the increasing fluctuating amplitude results in the unsteady dynamics for the ODW stabilization. It is found that both the formation wave structure and the transition pressure are changed due to the unsteady inflow, and a double-V wave structure appears. The interaction between the pressure disturbance and the stabilization wave structure leads to the oscillating ODW with convex and concave fronts. In particular, the low-pressure wave induces a larger wave angle with convex ODW and the concave one with unstable cellular wave structures is due to the high-pressure disturbance. The decrease of the disturbance cycle number results in a gradual evolution process of ODW stabilization, and the increase leads to the complex interactions of transverse waves, during which local quenching could occur. In general, the present results indicate that the stabilization wave structure of ODW is expected to re-adjust itself with local unstable features during a dynamic process and tends to be resilient to the inflow pressure disturbances.