Item 96025 gives a programmed method for the prediction of drag due to lift for planar and non-planar swept wings@ alone or in combination with a body. The method applies at subsonic speeds and when boundary-layer transition occurs near the wing leading edge. It uses an estimate of attainable wing leading-edge suction to establish a value for the wing lift-dependent drag between the limits appropriate to inviscid fully-attached flow and to fully-separated flow. The resolved components of the wing viscous axial force and of body axial force and normal force provide additional contributions to the total drag. The method incorporates a prediction of the variation of the wing lift coefficient with angle of attack which is based on the leading-edge suction analogy. The lift prediction includes the non-linear contribution from leading-edge vortex flow that is present for highly-swept wings@ together with a side-edge vortex contribution@ but the method is to angles of attack where the full realisation of the predicted potential flow contribution is not degraded by flow separation over the main part of the wing. The accuracy of prediction is expressed as CD < 0.01CL.
ESDU 96025 C-2004 history
2004ESDU 96025 C-2004 Drag due to lift for non-planar swept wings up to high angles of attack at subsonic speeds