Lessons from LESFOIL project on large-eddy simulation of flow around an airfoil

A synopsis of important results obtained by seven partners in the Brite-Euram project LESFOIL sponsored by the European Union is presented. This project was devoted to assessing the feasibility of large-eddy simulations (LES) for the computation of the flow around, an airfoil. As a test case, the Aerospatiale A-airfoil at Re = 2 x 10(6) and 13.3-deg angle of attack was chosen. All partners performed simulations of this How with various methods, most of which employed finite volume schemes and various subgrid-scale models of eddy-viscosity type. The key results of the individual partners' publications are presented in a comparative way. It is demonstrated that this configuration with realistic conditions for aeronautical flows is extremely demanding for LES. One reason is the need to achieve a threshold resolution for the adequate discretization of the attached and mildly separating boundary layer. The second and even more demanding requirement is the need for an adequate treatment of transition, which in the present computations was achieved by increased resolution.