Wind-Tunnel Study on a 65-deg Delta Wing at Sideslip

Abstract

The leeward vortices occurring over low-aspect-ratio delta wings typical of many current fighter aircraft cause highly nonlinear forces and moments. Near stall the vortices break down over the wing surface and introduce additional discontinuities and transients in the aerodynamics. Experimental studies of these flows are needed to develop mathematical models to represent the interaction between the vehicle motion and the forces and moments. The models will permit design for increased maneuverability in future fighters. Many static and dynamic tests of a common 65-deg swept delta wing in pitch and roll were conducted. Here, the effects of sideslip on the flow over a flat-plate 65-deg swept delta wing tested at a geometric angle of attack of 30 deg are described. At this angle of attack, the major part of the flow over the wing is affected by vortex core breakdown. Sideslip causes a strong asymmetry in the breakdown location