Turbulence statistics in a fully developed channel flow submitted to a high temperature gradient

Direct numerical simulations of a turbulent channel flow submitted to a high temperature gradient are performed. The temperatures of the channel walls are imposed to 293 K for the cold one and 586 K for the hot one. In this configuration, the flow is subsonic, while temperature variations can be strong and induce significant variations of the fluid properties. The unsteady low Mach number Navier-Stokes equations are solved numerically at a Reynolds number of 6400, based on mean centreline velocity, mean centreline viscosity and channel half-width. The mesh that contains about 470 millions of grid points allows to resolve all essential turbulence scales and no subgrid model is used. The independence of the mesh resolution is shown. A large number of turbulence statistics are computed. The profiles obtained at the cold and at the hot walls are compared using different non-dimensionalizations. The coupling between the turbulence and the temperature gradient is shown to modify the mean and the fluctuation profiles.