Résumé
The present investigation is motivated by the simulation of high-Reynolds number massively separated flows, a challenging problem of prime interest in industry. The turbulence model is based on a hybridization strategy which blends a vari-ational multiscale large-eddy simulation (VMS-LES) equipped with dynamic subgrid scale (SGS) models and a two-equation RANS model. The dynamic procedure (Germano) allows the adaptation of the constant of the SGS model to the spatial and temporal variation of the flow characteristics, while the VMS formulation restricts the SGS model effects to the smallest resolved scales [1]. The hybridization strategy uses a blending parameter, such that a VMS-LES simulation is applied in region where the grid resolution is fine enough to resolve a significant part of the turbulence fluctuations, while a RANS model is acting in the regions of coarse grid resolution [2]. The capability of the proposed hybrid model to accurately predict the aerodynamic forces acting on a circular cylinder in the supercritical regime and on tandem cylinders are investigated.