Transition structure and steadiness of oblique detonations with hot jet from the wedge

The oblique detonation wave (ODW) engine is potential to air-breathing hypersonic propulsion, and its wave adjustments are critical to achieving a wide range of flight conditions. The hot jet is capable of actively controlling the wave system by reducing the initiation length and adjusting the location of the wave surface, but the interactions between them have not been fully addressed. In the current research, hot jets from the wedge are utilized to explore the characteristics of ODW. The transition structure under varying hot jet parameters, including injection angle, pressure and position, was analyzed. It is found that there is a critical injection angle that promotes initiation. Hot jets can not only reduce the induction length for a faster detonation transition, but also inhibit initiation by destroying the reactive front. When the injection angle is larger than the critical value, the initiation length becomes sensitive to changes in the angle. When the injection pressure and position of the hot jet are modified, the wave system exhibits a phenomenon of periodic oscillation, and a detailed analysis of the transition structure and oscillation characteristics within one cycle is provided. Moreover, the action of the hot jet is weakened when its injection position changes from the reaction region to the post-detonation region. Four ODW statuses are summarized with the interaction of hot jet, revealing the action law for ODW engine applications.