VISUAL OBSERVATIONS OF SUPERSONIC TRANSVERSE JETS

We present experimental results on penetration of round sonic and supe rsonic jets normal to a supersonic cross flow. It is found that penetr ation is strongly dependent on momentum ratio, weakly dependent on fre e-stream Mach number, and practically independent of jet Mach number, pressure ratio, and density ratio. The overall scaling of penetration is not very different from that established for subsonic jets. The flo w is very unsteady, with propagating pressure waves seen emanating fro m the orifice of helium jets.