Dynamic slip-based wall-modeled Large-Eddy Simulations of turbulent flows with separation and reattachment in a Discontinuous Galerkin framework*

Slip-based wall modeling is a promising wall-modeled large-eddy simulation (WMLES) approach to predict complex turbulent flows (Bose and Moin PoF 2014). Slip-wall model predictions are, however, sensitive to the choices of model coefficient, and the proposed dynamic models are not robust even for attached boundary layers (Bae et al. JFM 2019). In this work, we apply a new dynamic slip-wall model to predict smooth body separation in benchmark test flows subject to favorable and adverse pressure gradients over curved geometries. The new dynamic model is formulated in a consistent Discontinuous Galerkin framework and leverages the universal scaling relationship of Pradhan and Duraisamy JFM 2023. The model dynamically estimates the universal scaling parameter and the slip-wall coefficient is based on an optimal finite-element projection framework. The wall model coupled with the dynamic Smagorinsky model gives predictions for the mean velocities and Reynolds normal and shear stresses that match well with the available experiments and DNS in the reverse flow and post-reattachment regions. Proper length scales and a slip Reynolds number in the model formulation allow for robust model performance on significantly under-resolved LES meshes across a range of high Reynolds numbers.