Dynamic response characteristics of wave systems to wedge control in hydrogen-fueled oblique detonation engines

Interference between oblique detonation waves and walls in confined spaces is inevitable. When these detonation waves reflect and generate Mach stems，there is a sharp increase in total pressure loss in the airflow，lead⁃ ing to potential instability in the detonation wave system. Thus，flow control becomes a crucial method for stabilizing oblique detonation combustion. This paper selects a hydrogen-air mixture，and for the first time applies the overlap⁃ ping grid technology to the numerical simulation of oblique detonation. The dynamic response characteristics of station⁃ ary and non-stationary detonation wave systems to different wedge movement strategies are compared. The study finds that for the stationary reflection wave system，moving the wedge downstream facilitates the transition from a Mach reflection structure to a recirculation zone structure，with the speed of wedge movement significantly affecting the characteristics of wave system changes during the flow field evolution. For the non-stationary reflection wave system，the development and merging of the Mach stem and the subsonic area downstream of the reflected shock are the main causes for flow congestion and wave system instability. The evolution process of the oblique detonation reflection flow field shows that only when the wedge movement can reduce the area of the subsonic region behind the wave and dis⁃ rupt the flow congestion structure within the flow field can the unstable detonation wave system be restabilized. The ef⁃ fectiveness of wedge movement control depends on the relative speeds of the Mach stem movement and the wedge control speed，with the existence of velocity boundary during deceleration（Vw = 1. 52 VMS + 65）and acceleration（Vw = 1. 56 VMS + 92）. © 2024 Chinese Society of Astronautics. All rights reserved.