Measurements of leading edge vortices in a supersonic stream

An experimental study of the supersonic vortices from a 75° sweptback 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 utilizing 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 core¹ is found to have strong wake-like profile.