Numerical study of flow structures and mixing characteristics of a sonic jet in supersonic crossflow

This study numerically investigated the influence of flow structures on the mixing characteristics of a sonic transverse gaseous ethylene jet in a supersonic crossflow with a Mach number of 2.95. RANS (Reynolds Average Navier-Stokes) simulations were employed to reveal the transport mechanism of jet fluid. The influencing factors, the jet-to-crossflow momentum flux ratio (J) and the nondimensional thickness of the turbulent boundary layer in the mixing characteristics of the sonic transverse gaseous jet are investigated. In the near-wall field, there is a V-shaped region in the front of the separation bubble that contains more jet gas under a lower momentum flux ratio (J) condition, which is caused by the collision of different inflow streamlines. As the turbulent boundary layer grows, there is more space for the jet gas to expand so that the penetration of the jet is much higher. •The significant jet fluid entrainment can be attributed to the major CVP structures.•The fluid in the near-wall region of the far-field is entrained by the inflow.•There is a V-shaped region with higher fuel mass fraction located in the front of the recirculation zone.•Thicker turbulent boundary layer can promote fuel/oxidizer mixing.