Unified wall-resolved and wall-modeled method for large-eddy simulations of compressible wall-bounded flows

We present a general strategy to unify wall-resolved and wall-modeled large-eddy simulation (LES) approaches for turbulent wall-bounded compressible flows. The proposed technique allows one to impose the proper wall stress and heat flux, preserving the no-slip and the isothermal and adiabatic conditions for the velocity and temperature fields, respectively. The approach results in a minimal intrusive algorithm that automatically switches between wall-resolved and wall-modeled LES according to the local near-wall resolution. The methodology is discussed and implemented in a flow solver based on high-order finite difference schemes, the application of which in the context of wall-modeled LES has been less explored in the available literature. Numerical simulations of canonical turbulent channel flow and spatially evolving boundary layer are performed in a wide range of Mach and Reynolds numbers. The results highlight the ability of the present method to accurately reproduce the outer layer turbulent dynamics, with a minimal influence of the near-wall grid resolution. In particular, velocity statistics and two-point spatial correlations are in good agreement with reference direct numerical simulation and wall-resolved LES, confirming the potential of the proposed approach for predictive analysis of wall-bounded flows at high-Reynolds number.

Automated summary

The study presents a general strategy to unify wall-resolved and wall-modeled large-eddy simulation approaches for turbulent wall-bounded compressible flows. The proposed technique allows for accurate reproduction of outer layer turbulent dynamics and automatic switching between the two LES methods. Numerical simulations demonstrate the potential of the approach for predictive analysis of wall-bounded flows at high Reynolds numbers.