Detached-eddy Simulation Applied To Flow Over An Elliptic Airfoil Near Stall

Predictions of the flow around an elliptic profile are obtained using Detached Eddy Simulation at chord Reynolds number of 7.21x106. Lift and drag coefficients (Cl and Cd) are computed from zero lift to angles above stall and compared to experimental da ta and to those obtained from RANS S-A model. The analysis focuses on the 3D unsteady effects and the influence of RANS zone size on the DES predictions. The accuracy of DES predictions is superior to that of S -A model and the computed values of Cl and Cd are in good agreement with experimental data up to stall point. Flows visualizations demonstrate unsteady flow structure dominate by Von Karman vortices. The shedding process and forces modulation appears to be represented reasonably at least in relation to adequate value of Strouhal number (St=0.25) for this Reynolds number. The DES is observed to provide sufficient unsteady information in the resolved range.