Investigation on C2H4-Air combustion mode in a non-premixed rotating detonation combustor

Based on the working characteristics of the rotating detonation combustor, the combustion mode of C₂H₄-Air under non-premixed injection conditions is experimentally studied in this paper. By changing the equivalence ratio, we observed the acoustic deflagration mode, fast deflagration mode, stable detonation mode, and weak detonation mode in the combustor. The velocity and pressure of the shock wave increase gradually as the equivalence ratio increases from 0.6 to 1.8. The stable detonation region appears near the stoichiometric ratio and the velocity of the detonation wave is relatively stable. When the equivalence ratio of the mixture is larger than 1.32, the stable detonation wave will suddenly extinguish, forming a weak detonation mode until the end of the combustor operation. The combustion mode of weak detonation is greatly affected by the fuel injection pressure ratio, and the release rate of energy is the main reason for the formation of deflagration mode or detonation mode.