We found a match
Your institution may have access to this item. Find your institution then sign in to continue.
- Title
On robust boundary treatments for wall‐modeled LES with high‐order discontinuous finite element methods.
- Authors
Fukushima, Yuma; Haga, Takanori
- Abstract
Summary: To robustly and accurately simulate wall‐bounded turbulent flows at high Reynolds numbers, we propose suitable boundary treatments for wall‐modeled large‐eddy simulation (WMLES) coupled with a high‐order flux reconstruction (FR) method. First, we show the need to impose an auxiliary boundary condition on auxiliary variables (solution gradients) that are commonly introduced in high‐order discontinuous finite element methods (DFEMs). Auxiliary boundary conditions are introduced in WMLES, where the grid resolution is too coarse to resolve the inner layer of a turbulent boundary layer. Another boundary treatment to further enhance stability with under‐resolved grids, is the use of a modal filter only in the wall‐normal direction of wall‐adjacent cells to remove the oscillations. A grid convergence study of turbulent channel flow with a high Reynolds number (Reτ≈5200$$ R{e}_{\tau}\approx 5200 $$) shows that the present WMLES framework accurately predicts velocity profiles, Reynolds shear stress, and skin friction coefficients at the grid resolutions recommended in the literature. It was confirmed that a small amount of filtering is sufficient to stabilize computation, with negligible influence on prediction accuracy. In addition, non‐equilibrium periodic hill flow with a curved wall, including flow separation, reattachment, and acceleration at a high Reynolds number (Reh≈37,000$$ R{e}_h\approx 37,000 $$), is reported. Considering stability and the prediction accuracy, we recommend a loose auxiliary wall boundary conditions with a less steep velocity gradient for WMLES using high‐order DFEMs.
- Subjects
TURBULENT boundary layer; REYNOLDS number; FINITE element method; REYNOLDS stress; TURBULENCE; FLOW separation; LARGE eddy simulation models
- Publication
International Journal for Numerical Methods in Fluids, 2024, Vol 96, Issue 7, p1170
- ISSN
0271-2091
- Publication type
Article
- DOI
10.1002/fld.5281