Résumé
We present a new numerical model for the simulation of turbulent flows. New
numerics rely on a 3D upwind compressible solver which applies to (possibly unstructured)
tetrahedrizations. Accuracy in boundary layers is increased by a new type of tetrahedrization.
The Reynolds-Averaged Navier-Stokes (RANS) equations are solved using
a mixed element-volume method for the spatial discretization and an implicit scheme is
applied to advance the equations in time. Two low Reynolds number k-e RANS models
are implemented with this numerical technique. A linear model, the low Reynolds number
k-e turbulence model of Goldberg et al., and a nonlinear one using a cubic relation between
the strain and vorticity tensors and the stress tensor, as originally proposed by Craft
et al. These models are applied to the study of a turbulent flow past a backward-facing
step. The results obtained are compared to experimental data