Dynamics of Small Scale Rotating Detonation Rocket Engines

The development of small scale rotating detonation rocket engines (RDREs) is expected to be constrained by both the intrinsic detonation length scale (detonation cell size) and the dynamics of the mixing process ahead of the combustion wave. Using high-fidelity numerical simulations, the present study probes the dynamics of the mixing ahead of the detonation wave in a 25~mm RDRE with discrete injection of gaseous methane (CH4) and oxygen (O2). For the conditions studied, mixing due to the impinging gas injection is not sufficiently fast and is supplemented by mixing induced by a complex, irregular leading shock structure. The subsequent strong heat release occurs in a heterogeneous mixture in close proximity to the leading shock structure.