Hybrid Large-Eddy Simulation / Reynolds-Averaged Navier-Stokes Simulations of Sonic Injection into Mach 2 Crossflow

摘要

This paper presents numerical simulations of sonic injection of ethylene into a Mach 2 crossflow of air. Experimental Raman scattering imagery, pressure-sensitive paint data and NO-PLIF images are compared with hybrid LES/RANS simulations. The impact of a low-diffusion method on the hybrid LES/RANS solutions is investigated. The effect of grid coarsening is also investigated. The low-dissipation approximation (LD-PPM) is shown to be less impacted by the grid coarsening, but it is numerically unstable at high injection pressures. A three-dimensional visualization of velocity tensor discriminant is used to show the differences between the vortical structures of PPM and LD-PPM as well as the impact of grid coarsening on these structures. The implications of these findings on future research is also presented.