The sudden viscous dissipation mechanism for a multi-species turbulent flow*

Previous work carried out by Davidovits & Fisch [Phys. Rev.Lett. 116, 105004 (2016)] demonstrated a rapid and sudden viscous dissipation of turbulence when viscosity has a greater sensitivity on temperature. We extend on the previous work by conducting direct numerical simulations of this sudden viscous dissipation for a multi-species, rather than a single-species, fluid. This allows for the use of complex multi-component models for viscosity, conductivity, and diffusivity that are based on plasma transport theory for weakly and strongly coupled plasmas. Results obtained with these transport models are compared against simulations performed with the simpler fluid formulations based on constant Prandtl and Schmidt numbers. Among the quantities of interest to be described are the energy transfer between the turbulent kinetic energy and the internal energy, as well as statistics relevant to the mixing of the multiple species. Finally, the high-fidelity data is used to measure the ability of Reynolds-averaged Navier-Stokes models to predict the sudden viscous dissipation for multi-component flows.