Evolution and Control of Oblique Detonation Wave Structure in Unsteady Inflow

Abstract

Oblique detonation engines have promising applications in hypersonic propulsion due to their compact combustor and high thermal efficiency. However, it is still challenging to achieve stabilized oblique detonation wave in a broad range of flight conditions. This work aims to study the evolution of oblique detonation wave structure in an unsteady inflow with sinusoidal velocity disturbance and to propose a control method to maintain a stable oblique detonation wave in an unsteady inflow. Simulations are conducted for oblique detonation waves in a stoichiometric hydrogen/air mixture, and the detailed chemistry is considered. Results demonstrate that for low-frequency inflow disturbances the autoignition point on the wedge exhibits a smooth trajectory. In contrast, high-frequency inflow disturbances give rise to a new reaction front that subsequently triggers a detonation wave within the induction region, resulting in an abnormal path for the autoignition point. A proportional controller is effectively used to maintain the autoignition point at the desired position, thus stabilizing the oblique detonation wave in unsteady inflow conditions. By implementing the proportional controller, the oblique detonation wave retains relative stability. Moreover, the proportional controller exhibits robust performance in nonideal inflows affected by other types of disturbances, including temperature and attack angle perturbations.