Unsteady transverse gas injection in a supersonic nozzle flow

The gasdynamic processes accompanying the injection of a pulsed gas jet into the diffuser part of a nozzle are considered in relation to the formation of control forces in rocket engines. The gas flow through the injection nozzle is controlled by a rotary damper. The finite volume method and moving mesh technology are used to discretize the Reynolds-averaged Navier–Stokes equations and the equations of the SST turbulence model. The effect of the opening time of the damper on the dynamics of the formation of the control force, as well as the dependence of the traction and energy characteristics of the nozzle on the flow rate of the injected working fluid, are studied. The results of calculations within the non-steady-state and quasi-steadystate problem statement are compared. The formation of the shock wave and vortex structure of the flow is discussed. Conclusions are drawn about the effect of the input parameters of the problem on the coefficient of the traction change.