Experimentally-Benchmarked kinetic simulations of heat transfer through rarefied gas with constant heat flux at the boundary

Abstract

In many applications, the heat flux at the surface is known instead of the surface temperature. In addition, in some applications, like vacuum drying or high altitude flights, the pressure is below atmospheric pressure, so the rarefaction effects become important, and therefore, the Navier-Stokes-Fourier equations fail to predict gas thermal behavior. In this paper, a constant heat flux boundary condition is developed and implemented in the frame of the Shakhov model kinetic equation, with the possibility to simulate the diffuse-specular reflexion of the molecules from the surface. The developed technique is implemented for the simulation of gas heat transfer in a two concentric cylinders configuration, similar to vacuum drying of used nuclear fuel canisters. The numerical results obtained using developed approach are compared with experimental data of heat transfer through rarefied gas between two concentric cylinders.