Mean Flow Field of a Nonbuoyant Rectangular Surface Jet

Abstract

The flow field for a low Froude number nonbuoyant rectangular surface jet is studied using laser induced fluorescence and laser Doppler velocimetry. It is shown that a surface current develops in turbulent, but not in laminar jets. The existence of a self-similar regime is established. The lateral growth rate of the jet below the surface is about 4.8 times its vertical growth rate, while that of the surface current is 8.8 times. The vertical growth rate is about half that of a plane surface jet and less than one third that of a free axisymmetric jet. While the horizontal profiles of the streamwise velocity are similar to those observed in free, submerged, and wall jets, the vertical distributions are distinctly flatter.