Effect of equivalence ratio on the velocity of rotating detonation

• Detonation velocity first increases and then decreases with increasing equivalence ratio.
• Detonation velocity is related to specific heat ratio and combustion heat.
• Unsteady flow causes fluctuations of detonation velocity.

Rotating detonation engines having the advantages of high thermal efficiency, high specific impulse and simple structure, are being studied widely. Rotating detonation waves in hydrogen–oxygen mixture are experimentally and numerically studied here. Two pressure sensors at different positions in the combustor capture the detonation pressure signals in the experiments. Mass flow rates are measured by gas mass flow controllers and rotating detonation waves at different equivalence ratios are obtained. Both experimental and numerical results show that as the equivalence ratio increases, the velocity of the rotating detonation wave first increases and then decreases while the velocity of the detonation wave decreases monotonously according to the previous study.