Numerical estimation of the thrust performance on a rotating detonation engine for a hydrogen-oxygen mixture

The numerical simulations of 2D and 3D rotating detonation engines for a hydrogen-oxygen mixture are performed using a detailed chemistry model. The comparison of 2D/3D flow fields for the same injection conditions indicates that the overall flow structures are in agreement for the two simulations and that both rotating velocities are approximately 96% of the CJ value. However, Isp for the 2D RDE is approximately 10 s larger than Isp for the 3D RDE. The grid resolution study indicates that the higher grid resolution produces detonation cellular structure; however, its effects on Isp are approximately a few seconds. Although Isp in the 2D smallest scale for higher mass flow is approximately 10 s larger than that of the other large scales, Isp for low mass flow is not affected by the scale. However, 3D scale effects are important because the radius of curvature along the circumferential direction changes, which affects the propagation of the rotating detonation. Because Isp and thrust are governed by the stagnation pressure and the micro-nozzle area ratio, the mass flow rate from the injector also depends on these parameters. Isp and thrust for RDE are found to be correlated with the mass flow rate, similar to the case of a conventional rocket engine. This result indicates that the two important parameters, A∗/A and p0, can be replaced by one parameter, i.e., the mass flow rate.