Measurements in a Jet-Pipe Flow Issuing Perpendicularly Into a Cross Stream

Abstract

Measurements are presented of velocity fluctuation statistics in the jet-pipe of a jet in a cross-flow situation for various values of the jet-pipe to cross-flow velocity ratio. The nonuniformities of the velocity profiles inside the pipe extend as far as 3 pipe-diameters upstream of the exit plane for small velocity ratios and to 2.5 diameters for higher velocity ratios. Longitudinal flow acceleration and strong streamline curvature affect turbulence activities at the exit plane for small velocity ratios. The horseshoe vortex which is formed in front of the exit plane results in a streamline curvature with a stabilizing effect on turbulence in the nearby flow field while the streamlines are unstably curved everywhere else. At high velocity ratios the pipe flow is very weakly affected by the cross-flow.