Effect of heat release on a gas flow in a channel with a variable cross section

The influence of the longitudinal distribution of heat release in a supersonic combustion of propane under the conditions of an unsteady pulsed discharge on the gas flow regime in a rectangular channel with a variable cross section is studied. It is shown that, with an increase in the mass flow rate of propane, the thrust arising from the supersonic combustion of a lean hydrocarbon fuel in an expanding aerodynamic channel, the pressure jump in the combustion area, and the air temperature in the closed pressure chamber increase. It is revealed that there is a limiting amount of hydrocarbon fuel that can be burned in a supersonic combustion regime in an expanding rectangular aerodynamic channel with side expansion angles $\alpha = \beta = 5^{\circ}$ without transition to a subsonic flow, while the ratio of the exit and entry sections $S_2/S_1$ is $12.7$. The experimental results are in satisfactory agreement with the data of mathematical modeling with allowance for additional heating of the cold supersonic flow in the region of an unsteady pulsed discharge.