Effect of ozone addition on oblique detonations in hydrogen-air mixtures

Ozone addition is a promising method to enhance the ignition processes and may have potential use in the practical application of oblique detonation engines (ODEs), especially under challenging low Mach number conditions where ignition is hard to achieve. In this study, numerical simulations are conducted to explore the effect of ozone addition on oblique detonations. Numerical results show that with ozone addition, the transition between the induction oblique shock wave (OSW) and oblique detonation wave (ODW) will be smoother at relatively high flight Mach number (from 9 to 10). The reasons for this wave system transformation are discussed. With the addition of ozone, the initiation of ODW can occur at a shorter distance and height, preventing the convergence of compression waves into shocks and resulting in a smoother transition. It was also found that adding ozone is an effective approach to decrease the initiation length, especially at a relatively low Mach number (9), which is crucial to the ODE's thermal protection. Furthermore, the effects of ozone addition on total pressure have been analyzed, demonstrating its positive influence on the propulsion performance of ODE. At a lower flight Mach number (8), ozone addition can re-stabilize the unsteady ODW with a normal detonation wave moving upstream. This is achieved by reducing the size of the subsonic regions, indicating that ozone addition can broaden the working flight Mach numbers of ODEs.