Determination of vortex burst location on delta wings from surface pressure measurements

A shape parameter for the vortex-induced upper surface pressure distribution on a delta wing has been derived from a simple two-dimensional potential flow model. For this model the half-width of the suction peak is a function solely of the vortex height above the wing surface. Published experimental data are used to show that this result holds for real delta wing flows at low angles of attack, thus allowing a good estimate of vortex trajectory and strength to be made from surface pressure measurements alone. At higher angles of attack, where the vortex burst region is over the wing, the simple model breaks down; however, the variation in half-width with both chordwise location and angle of attack appears to correlate well with the condition of the adjacent vortex. In particular, the burst point corresponds to an abrupt, well-defined change in half-width. This observation offers an alternative to flow visualization techniques for experimental determination of burst location.