Experimental investigation on propagation characteristics of rotating detonation wave with a hydrogen-ethylene-acetylene fuel

Abstract It is attracting much attention that the hydrocarbon mixtures are used as the fuel of rotating detonation engine when the oxidizer is air. In this study, a hydrogen-ethylene-acetylene mixture was used as the fuel of rotating detonation combustor to investigate the propagation characteristics of rotating detonation wave. An annular combustor, with an inner diameter of 124 mm and an outer diameter of 152 mm, was used in this research. The air and fuel were separately injected into the combustor through a slot-orifice injection structure. High-frequency pressure sensors and ionization probes were used to measure the detonation characteristics. Experiments could obtain a stable detonation wave whose velocity was about 65% of the C-J value, showing that there was a large velocity loss compared to hydrogen fuel, which reached a C-J velocity value of 94%. The detonation intensity for the hydrogen-ethylene-acetylene mixture is weaker than that of hydrogen. The equivalence-ratio range of forming a detonation wave with hydrogen-ethylene-acetylene mixture was narrower than that of hydrogen fuel with the same mass flow rate. The detonation-wave height of hydrogen-ethylene-acetylene mixture had similar results with hydrogen fuel.