Numerical study of detonation propagation under the action of supersonic pulsating flow in expanding combustor.

In this study, the effect of a velocity-pulsating stoichiometric hydrogen-oxygen mixture entering an expanding combustion chamber on the detonation wave is investigated. The hybrid sixth-order weighted essentially non-oscillatory centered difference scheme was used to solve the Navier–Stokes equations with a one-step two species chemistry model. The results verify that the induction zone is extended under the influence of pulsating flow. The discontinuous structure is formed in the flow field. A lot of unburned jets between the wavefront and the reaction zone were generated, which resulted in insufficient energy release. Coupled with the weakening of the wave strength by the Prandtl–Meyer (P-M) expansion fan, the detonation wave show different degrees of attenuation. The decay of the detonation wave shows different patterns at different amplitudes and periods. When the velocity amplitude is 0.3 V C J , the decay rate of detonation wave increases with the increase of the disturbance period. This attenuation law is different from the amplitude of 0.1 V C J and 0.2 V C J . This is because the discontinuous structure area formed by high-amplitude disturbance is large. Therefore, the longer its existence time is, the more serious the detonation wave attenuation is. • This paper is an innovative study on the propagation of detonation waves under pulsating velocity inflow. • Unburned jet generated by the expansion channel weakens the intensity of the detonation wave. • The propagation law of detonation wave varies with the period of velocity disturbance under different amplitudes. • Under the high-amplitude disturbance, the discontinuous structure impacts the propagation of detonation wave. [ABSTRACT FROM AUTHOR]