Vortex Structure Produced by a Laterally Inclined Supersonic Jet in Transonic Crossflow

Stereoscopic particle image velocimetry data have been collected for a supersonic jet exhausting into a transonic crossflow from a laterally inclined scarfed nozzle installed flush in a flat plate. Mean velocity fields and their derived vorticity were measured at a single crossplane in the far-field for varied jet-to-freestream dynamic pressure ratio J and nozzle inclination angles of 0, 15, 30, and 45 deg. The data reveal the induced counterrotating vortex pair and the horseshoe vortex formed as the jet exits the nozzle, both of which appear symmetric for the uncanted nozzle. As the nozzle inclination is increased, the vortex pair becomes tilted opposite the nozzle cant and shifts closer to the wall, where the lower vortex attains a larger strength than its counterpart until it eventually becomes so dominant that the opposite vortex is undetectable. Regardless of nozzle cant, vortex strengths increase with larger J. Vortex distances from the wall increase with J at lower nozzle cants, but at larger inclination, the position of the vortex nearer the wall varies less with J than does its complement. Thus, at a sufficiently large nozzle cant, the jet interaction effectively produces a single vortex whose position does not shift greatly with jet strength.