L.E.S. OF HEAT TRANSFER OVER A BACKWARD-FACING STEP
RÉSUMÉ
A large-eddy simulation (LES) of the flow over a backward-facing step was conducted to investigate the heat transfer phenomena in the reattachment zone. The Navier-Stokes equations for an incompressible fluid with the temperature field considered as a passive scalar are solved using a second-order accurate scheme in space and time. An original coupling is used with a previous simulation to impose a fully turbulent flow at the entrance of the domain. The Mixed Scale Subgrid Model is used for the momentum equations while a scalar subgrid diffusivity model is employed for the temperature equation. The mean reattachment length is well correlated to the maximum Nusselt number. Two main frequencies are identified: a high one due to the vortex shedding of the shear layer and a low one corresponding to the drift of the reattachment point.