Advances in subgrid-scale and wall modeling for simulations of complex, separated turbulent flows*

Recent studies (Agrawal et al., Phys. Rev. Fluids 2022; Goc et al., Ann. Res. Briefs, CTR 2020) have shown that traditional eddy viscosity models when used with the equilibrium wall model exhibit a non-monotonic convergence (on grid refinement) in the prediction of separation bubble sizes in certain mild adverse pressure gradient regimes such as those observed in the Boeing speed bump (Williams et al., AIAA Scitech 2020).

In this work, we focus on the impact of modeling closures in the vicinity and inside the separation bubble. We have developed a class of novel dynamic SGS models such as the dynamic tensor coefficient Smagorinsky model (DTCSM) and a variant of the mixed Clark model (DTCCM). In the simulations of flow over the Boeing speed bump, both DTCSM and DTCCM recover monotonic convergence of the quantities of interest (QoI) such as skin friction and pressure drag. DTCCM accurately predicts the QoI and the mean velocity profiles on relatively coarse grids w.r.t. the DNS (Uzun and Malik, AIAA J. 2022). Results from these simulations and other flows will be presented and compared against reference data.