Wave mode observation of hydrogen/oxygen driven rotating detonations in the hollow and annular rotating detonation rocket engine.

This article focuses on the experimental investigation of hydrogen/oxygen-fueled rotating detonation rocket engines (RDREs) with two combustor configurations: hollow and annular. Using dynamic pressure transducers and high-speed imaging, the study characterizes the propagation modes of rotating detonation waves (RDWs) under atmospheric pressure, identifying single-wave, two-wave co-rotating, and three-wave co-rotating modes. Results indicate that as the equivalence ratio increases, the number of detonation fronts decreases in both combustor types, but the hollow combustor supports stable RDW propagation over a broader equivalence ratio range with less velocity deficit and more concentrated frequency distributions than the annular combustor. These findings provide insights into RDW behavior relevant to the design and optimization of hydrogen/oxygen RDREs.