Optimal wall-modeling strategies using data.

Traditional wall modeling approaches for LES rely on a RANS-like description near the wall or computation of wall stresses using an equilibrium mean velocity profile. These models do not adapt to the underlying numerical method and are susceptible to sub-grid modeling errors and under-resolution. To resolve these inconsistencies, variational multiscale (VMS) decomposition of the flow-field is performed by the formal projection of the DNS solution on coarse-scale finite element basis functions. A direct consequence of the VMS decomposition is that the optimal coarse-scale solution and slip velocity are naturally obtained, thus defining an optimal wall model. To reach near-optimal wall-modeling performance, a model consistent training approach is employed to infer the parameters of slip and wall stress-based wall models that allow the recreation of velocity statistics present in the optimal coarse-scale solution.