Drag prediction for thick airfoils is improved

Friday April 8, 2016 08:21

Within WP2 a study has been performed to improve the drag prediction for thick airfoils for XFOIL like methods. The general methodology of the correction is applicable to a wide range of viscous-inviscid interaction methods using a two-equation lag dissipation integral boundary layer method. The proposed method is applicable in regions of angle of attack prior to stall as the correction can become negative in deep stall region where at the end of the wake, the predicted value of velocity at the edge of the boundary layer exceeds the magnitude of the free stream velocity. This happens in the case of massively separated flows over the airfoil which is outside the range of applicability of these computational methods. The correction is applicable to airfoils with a relatively small trailing edge thickness (h TE < 3% of chord). Present analysis is performed for a wake length of one chord which is adequate for most airfoils.