Numerical Study of One-Dimensional Detonation Propagation in Perturbed Inflow

Detonation waves in the static gases or stationary inflow have been investigated widely, but few studies on the detonations in perturbed inflow were performed before. The research is not only an important part of detonation propagation mechanisms, but also promotes the application of detonation-based propulsion systems. In this study, Euler equations coupled with a two-step kinetic model were used to simulate the dynamic features of one-dimensional detonation wave under the sinusoidal density perturbations. The relationship of the heat release rate and the inherent instability of detonation waves was obtained, and then the effects of disturbance wavelength and amplitude on the one-dimensional detonation dynamics were investigated systematically. Numerical results demonstrate that the continuous sinusoidal density perturbations could trigger the complex dynamic behaviors of one-dimensional detonation wave, which is sensitive to the inherent instability of detonation waves. For a stable detonation, the perturbation causes the pressure peak oscillation of leading shock within a certain disturbance wavelength range. For an unstable mixture, the disturbance could strengthen inherent instability of detonation wave. Besides, the disturbance amplitude plays a crucial role in the detonation dynamics, and an increase in disturbance amplitude can lead to a more unstable detonation wave.