A revised theoretical model for oblique detonation engines

Based on detonation combustion, oblique detonation engines are expected to achieve high performance at high Mach numbers. However, the existing theoretical models significantly overestimate the engine performance compared to the numerical simulation results. To bridge the gap between theory and practice, an ideal model of oblique detonation engines and a two-dimensional numerical simulation of an oblique detonation engine for a Mach 10, 30 km flight were carried out. The main reason is that the ideal model did not consider inlet capture efficiency, viscous drag, total pressure loss of engine components, and reduction in combustion efficiency. Revisions are proposed for these four aspects, and a zero-dimensional revised model of the oblique detonation engine is proposed. The results agree with the simulation and can be used to predict the performance of the oblique detonation engine. The revised specific impulses for hydrogen and kerosene engines are 1339.5 s and 593.7 s, with a difference of 4.1 % and 15.1 % from numerical results, respectively. The specific impulse decreases with increasing flight altitude and speed. For a typical flight altitude of 30 km, positive thrust can be produced within Mach 14. Other design parameters affecting the performance of the oblique detonation engine were studied.