Measurements of leading-edge vortices on a 75° delta planform wing at M = 2.5

An experimental study of the supersonic vortices from a 75° swept-back delta wing has been carried out in a Mach 2-49 stream. Five-hole conical probe surveys were conducted at the trailing edge of the planform for 7° and 12° angles-of-attack. The main objective was to determine the Mach number and pressure distributions in the primary vortex. A novel approach of utilising a computational flow solver was used to generate the calibration data for the five-hole probe over a range of Mach numbers and pitch angles. Measurements indicate significant static and total pressure deficits in the vortex core. Both the magnitude and the spatial scale of these deficits increase with the higher incidence angle. The swirl profiles have supersonic peak magnitudes and resemble the low speed Lamb-Oseen vortex. Similar to the case of supersonic wing tip vortices, and contrary to the experimental results from transonic and low speed leading-edge vortices, the axial Mach number distribution in the vortex core is found to have strong wake-like profile.