Influence of sideslip on double delta wing aerodynamics

Introduction D OUBLE delta wings are planforms that incorporate two distinct leading-edge sweep angles. The first part of the double delta wing, the strake, has a much higher sweep angle than its aft portion, the main wing. A double delta wing has been shown to have better aerodynamic performance than a simple delta wing of comparable area having the same sweep as the main wing of the double delta. The improved aerodynamic performance is due to the interaction of the vortices created by the strake and main wing. Very few studies have examined the performance of double delta wings in sideslip. In sideslip, each side of the wing experiences an effective change in sweep angle. The side leading into the flow, the windward side, will see an effective decrease in sweep angle, whereas the side trailing, the leeward side, will see an effective increase in sweep angle. On a double delta wing this can result in some very complex vortical interactions. This Note discusses the nonlinear behavior of a double delta wing examined in a low-speed wind tunnel at high angle of attack in sideslip. A significantly larger amount of data on the effects of sideslip for double delta wings is contained in previous references. 5