Effect of the gasdynamics of a two-regime combustor on the power characteristics of a model with combustion

Methods are analyzed for increasing the propulsive thrust-efficiency characteristics of the internal duct of a gasdynamic model with combustion by means of boosting the operational process stage. At a Mach number $5$ and a stagnation temperature between $1200$ and $1500$ K and $35$–$40$ MPa stagnation pressures we investigated the effect of the degree of combustor expansion $\bar{F}_c$ on the propulsive thrust-efficiency characteristics of a small model operating on hydrogen fuel with an air excess coefficient of $1$. The calculated predictions of the increase in the model characteristics on account of a reduced $\bar{F}_c$ were confirmed experimentally. When the combustor operates in a regine, where the heat is being supplied to a subsonic flow, it is possible on priciple to reduce $\bar{F}_c$ to a minimum determined by the flow gas thermodynamics in the combustor.