Abstract
This study numerically investigates the effect of injector configuration on flow characteristics and performance of annular and cylindrical rotating detonation engine (RDE) combustors. For each type of the RDE combustor, stoichiometric hydrogen-air premixed gas was injected from the bottom (“base injection”) or from the side wall (“side injection”). In the side injection cases, thin vertical waves and high-pressure regions near the injectors were observed for both combustor geometries. Such pressure fields differ from the pressure fields observed in the combustors with bottom injectors. However, in all cases, more than 80% of the fuel was consumed, and the burned gas was accelerated to the speed of sound toward the outlet. In the side injection case, the ratio of the specific impulse to the theoretical value was about 98.3% for the annular combustor and 95.4% for the cylindrical combustor. The effect of injection configuration on the propulsive performance was not significant. Thus, it is concluded that RDEs with injectors on the combustor side wall can perform similarly to those with injectors on the bottom despite the different wave structures.
