Compressibility effect on turbulent mixing

Compressible mixing plays an important role in a variety of geophysical and engineering problems. These flows include complex physics such as entrainment, mass/momentum transfer, and viscous dissipation. While incompressible, homogeneous turbulence is relatively well understood, compressibility and heterogeneous flow pose challenges to the classical theory due to different energy transfer and dissipation mechanisms. For this purpose, we conduct high-fidelity numerical simulations to investigate how compressible turbulent flows propagate, mix, and decay. We evaluate the rate of mixing region growth and decaying turbulent kinetic energy and find that compressibility induces energy loss transferred to less energetic regions of the flow. We apply this energy loss to the scaling law accounting for compressibility effect for turbulent mixing caused by gradients in turbulent intensity and decaying turbulence in different geometries validated using direct numerical simulations.