HYBRID/ZONAL RANS/LES COMPUTATION OF AN AIRFOIL

Large-eddy simulations were carried out in the vicinity of the RAF-6E airfoil at incidence of 5° at a chord based Reynolds number of 122 000. Hybrid RANS/LES method was employed on a zonal domain of the airfoil. Appropriate boundary conditions were investigated for the interface between RANS and LES on 2D RANS simulations. In order to determine the required extension of the domain in the spanwise direction, three different grids were prepared. Streamwise velocity components and velocity fluctuations of these numerical simulations were compared with Laser Doppler Anemometry measurements in 10 profiles. Static pressure distribution on the surfaces of the airfoil was compared as well. The computed laminar to turbulent transition zone position was compared with flow visualization techniques.