Continuous detonation of $\mathrm{CH}_4/\mathrm{H}_2$–air mixtures in an annular combustor with varied geometry

Regimes of continuous detonation of $\mathrm{CH}_4/\mathrm{H}_2$–air mixtures with mass fractions of $\mathrm{H}_2$ in the fuel equal to $0$–$1/5$ are obtained in an annular combustor $503$ mm in diameter with variation of the combustor geometry. The influence of the combustor geometry on the velocity and number of transverse detonation waves, pressure in the combustor, and specific impulse is considered. It is found that three-fold constriction of the combustor exit cross area allows obtaining two-wave regimes of continuous spin detonation in the pure methane-air mixture. Based on stagnation pressures measured at the combustor exit, the specific impulses in the case of continuous detonation are determined for different compositions of the fuel.