Development of Compressible Large-Eddy Simulations Combining High-Order Schemes and Wall Modeling

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Development of Compressible Large-Eddy Simulations Combining High-Order Schemes and Wall Modeling

Le Bras, S

Compressible large-eddy simulations combining high-order methods with a wall model have been developed in order to compute wall-bounded flows at high Reynolds numbers. The high-order methods consist of low-dissipation and low-dispersion implicit finite volume schemes for spatial discretization on structured grids. In the first part, the procedure used to apply these schemes in near-wall regions is presented. It is based on a ghost cell reconstruction. Its validity is assessed by performing the large-eddy simulation of a turbulent channel flow at a friction Reynolds number of Reτ=395. In the second part, to consider flows at higher Reynolds numbers, a large-eddy simulation approach using a wall model is proposed. The coupling between the wall model and the high-order schemes is described. The performance of the approach is evaluated by simulating a turbulent channel flow at Reτ=2000 using meshes with grid spacings of Δx+=100, 200, and 300 in the streamwise direction and Δ+=50, 100, and 150 in the wall-normal and spanwise directions (in wall units). The effects of the choice of the point used for data exchange between the wall model and the large-eddy simulation algorithm, as well as of the positions of the ghost cells used for the coupling, are examined by performing additional computations in which these parameters vary. The results are in agreement with direct numerical simulation data. In particular, the turbulent intensities obtained in the logarithmic region of the boundary layers of the channel flow are successfully predicted.