Investigation of Supersonic Jet into Compressible Subsonic Cross Flow on the Surfaces around the Jet Exit

An experimental study has been performed to investigate the flow physics of an under-expanded axisymmetric supersonic jet exhausting transversely from a flat plate into a subsonic compressible cross flow. The goal was to study the effects of boundary layer thickness ratio (δ/D) and the jet to free stream dynamic pressure ratio (J) on surface pressure. The resulting measurements distinctly show that both the magnitude and the width of the positive and the negative pressure coefficient regions in front and behind the jet increase with J. In addition, the side region of the jet affects the jet plume and as J increases, the pressure coefficient decreases at this region. The data acquired upstream of the jet reveal that, with increasing δ/D, the magnitude of the positive pressure coefficient region decreases, While the recovery of the back pressure downstream of the jet moves in the vicinity of the nozzle exit.