Numerical Simulation of Jet Mixing in Supersonic Crossflow: Effect of Jet Exit Geometry

Implicit large-eddy simulation/Reynolds-averaged Navier-Stokes hybrid simulation of sheet-like hydrogen jets in a supersonic crossflow are performed to investigate jet mixing, focusing on the difference in flow structures between sheet-like jets and round jets. The simulation is validated with a helium jet experiment in terms of the mean concentration. The numerical results showed good agreement with the experimental results. A characteristic of injection from the sheet-like jet exit is the spread of the windward jet toward the spanwise direction owing to the strong interaction with the freestream, while the leeward jet highly penetrated the freestream. In the investigation on jet mixing using different jet exit geometries, it was found that the sheet-like jet has a lower mixing efficiency compared with the round jet. The two mixing characteristics of the sheet-like jet are (i) a large jet cross-sectional area, and (ii) a weak turbulent mixing in the windward shear layer. As the effect of the momentum flux ratio on the jet mixing with sheet-like jet port, the mixing is enhanced with increasing the momentum flux ratio.