An investigation of a mixed-convection in a rarefied gas

We investigate heat transfer in a rarefied gas in a lid-driven cavity flow initiated by instantaneously heating and cooling opposite walls for different flow regimes. Volume diffusion model is used as an extension to the standard Navier-Stokes-Fourier set for simulating the flows. Numerical simulations are presented and compared with standard Navier-Stokes-Fourier. For higher Knudsen numbers the volume diffusion model captures non-local equilibrium effects in corners of the cavity that are missed by the Navier-Stokes-Fourier model. It is generally observed that one can use volume diffusion correction to capture disequilibrium effects in high rarefaction regimes.