Leading-Edge Treatments for Wall-Modeled Large-Eddy Simulation of an Airfoil

Wall-modeled large-eddy simulations (WMLES) of the Aerospatiale A-airfoil flow at Reynolds number of [Formula: see text], angle of attack of 13.3 deg, and Mach number of 0.15 are used as a test bed for exploring how to handle the thin laminar boundary layer and how it transitions to turbulence in a WMLES context. It is shown that application of the wall model everywhere with an unsuitable exchange location can lead to excessive boundary-layer growth and up to 10% underprediction of the lift coefficient. Several numerical approaches are examined to handle the laminar region of the airfoil flow within the WMLES framework. A transition sensor is implemented to locally detect where the boundary layer is laminar or turbulent and then used to dynamically activating or deactivating the wall model. The sensitivity of the predictions to the mesh resolution and the exchange location is explored.