Numerical simulation of argon injection into supersonic crossflow at various jet-to-freestream momentum flux ratios

In the paper, the results of numerical modeling are presented of the 3D turbulent flows in a channel with backward-facing step, and argon jets injected into the supersonic crossflow. The numerical simulations are carried out under the conditions of experiments performed at the hot-shot wind tunnel IT-302M ITAM SB RAS for flow parameters as follows: Mach number at the entrance of the channel M=3.86, the total temperature T0 = 1650 K, and the total pressure P0 = 5.5 MPa. Sound jets of argon are supplied from two circle orifices located opposite each other on the channel walls before the backward-facing step. A series of calculations have been performed with a change in the jet supply pressure from 1 to 5 MPa, which ensures the variation in the jet-to-crossflow momentum flux ratio in the range J = 0.7 ÷ 6. Mathematical modeling was carried out using ANSYS Fluent based on the Reynolds-Averaged Navier- Stokes equations supplemented by the k-m SST turbulence model. A comparison of the calculated and experimental data on the static pressure distributions on the walls indicates a satisfactory agreement. The calculated results made it possible to obtain a clearer understanding of the 3D flow structure in the channel and reveal the influence of the injection pressure on the level of mixing along the channel. The obtained data can be used to select the parameters for the injection of heavy hydrocarbon fuels in the combustion chamber of the scramjet engine at flight Mach numbers M > 8.