Constrained Large-Eddy Simulation for Aerodynamics

Abstract

A constrained large-eddy simulation (CLES) method for wall-bounded compressible flow is introduced and validated via simulations of several typical flow configurations, including compressible turbulent channel flow, flow past a NACA0021 airfoil at 60\(^\circ \) angle of attack, and compressible flow past a Delta wing. In the wall-bounded compressible CLES method, the whole flow domain is solved using large-eddy simulation (LES) technique, but the subgrid-scale (SGS) stress and heat flux are constrained by given models for the Reynolds stress and heat flux in the near-wall region. For attached flows, CLES method can eliminate the non-physical Log-Layer Mismatch phenomenon appearing in hybrid RANS/LES methods, and can predict the mean velocity and temperature profiles more accurately as compared with traditional LES and detached-eddy simulation (DES) approaches. For detached flows, CLES method can calculate the skin friction force more precisely than traditional LES method, and is comparable to DES technique in prediction of the aerodynamic statistics. For both cases, CLES method can capture fruitful multiscale turbulent structures, which are lacking in DES, and can successfully overcome the coarse-grid effect observed in traditional LES method. Therefore, it is suggested that the present CLES method could be a promising numerical simulation tool for wall-bounded compressible turbulent flows in the realm of aerodynamics.