Study of sonic injection from circular injector into a supersonic cross-flow using large eddy simulation

Large-eddy simulations have been performed to investigate the flow coherent structures and mixing characteristics in a Scramjet combustor having a sonic hydrogen injection from circular injector into a supersonic cross-flow with three different jet to cross-flow momentum flux ratios. The numerical results show that the jet penetration is not only influenced by momentum flux ratio but also significantly influenced by reflected shocks due to the upper wall. A bending down location of jet penetration could be observed just near the place where reflected shock interacts with the jet shear layer. Mixing efficiency was used to the quantitative analysis of the mixing process. In addition, the bow shock formed in the near field heats the mixture of air and hydrogen and leads to nonlinear distribution of temperature filed in mixture fraction space, which has the same logarithmic form in mixture space under the three momentum ratios with the same inlet stream Mach number.