Large-eddy simulations of a Benchmark on the Aerodynamics of a Rectangular 5:1 Cylinder

The present work results from a collaborative and complementary effort of two teams involved in Large Eddy Simulations (LES) of the Benchmark on the Aerodynamics of a Rectangular 5:1 Cylinder (BARC). The results obtained for the BARC configuration through two different models in the LES framework, two different discretization methods and two different codes are considered in the present contribution. The first set of simulations has been carried out by means of the OpenFoam finite volume open source code. The classical LES approach is considered, in which the equation system is closed by a transport equation for the kinetic energy of the unresolved stresses. The second set of simulations employs a proprietary research code based on a mixed finiteelement/finite-volume discretization on unstructured grids. Variational MultiScale (VMS) LES combined with eddy-viscosity subgrid scale models are used for turbulence modeling. The assessment of quality and reliability of LES results is addressed: the results obtained with the two different approaches are compared together and with available experimental data. The sensitivity to the subgrid scale model, to the flow Reynolds number and to the grid resolution is investigated for the VMS-LES simulations, while the effects of the spanwise gride density and of the spanwise domain length are studied in the classical LES simulations.