Effects of Divergence Inlet on Kerosene/Air Rotating Detonation Engines

In this paper, an improved three-dimensional conservation element and solution element method with chemical source terms is developed and applied to investigate the effects of different divergence inlet patterns on vapor kerosene/air rotating detonation engines. A two-step kerosene/air chemistry model is adopted and solved by a third-order Runge-Kutta method. A series of cases with varying the slot inlet width, in other words, 6, 4, and 2 mm, and divergence section length, in other words, 4, 6, and 10 mm, are simulated. The simulation results indicate the supersonic injection generated by the divergence section is helpful to decrease the disturbance from the downstream flow. Affected by the divergence section, the detonation front is divided into two sections, in other words, the main detonation front and the banded detonation front. For the main detonation front, the detonation strength on the outer wall is significantly stronger than that on the inner wall, while it is not for the banded detonation front. The total pressure loss caused by the inlet normal shock significantly increases with the decrease of slot inlet width. A declining deflagration surface will appear when a small slot inlet width of 2 mm is used. The rotating detonation engine (RDE) performance analysis shows that the slot inlet width has a significant impact on the thrust, specific impulse, total pressure gain, and outlet Mach number. A bigger slot inlet area ratio contributes to a higher total pressure gain. The simulation results can get insight into rotating detonation behaviors and guide the development of the kerosene/air RDE.