LABORATORY EXPERIMENTS OF A JET IMPINGING ON A STRATIFIED INTERFACE

The entrainment rates of vertical and inclined jets impinging on a str atified interface are measured in water tank experiments. At moderate Richardson number, the entrainment rate of the vertical jet is proport ional to Ri(-1/2), independent of Reynolds number. The inclined jets a re tilted at 150 from the vertical. In one case, the jet nozzle is rot ated about a vertical axis, so that the inclined jet precesses, while in the other, it is stationary. The inclined jets entrain at a rate pr oportional to Ri(-3/2), whether precessing or not. This behavior is co nsistent with a new model of stratified entrainment which accounts for vortex persistence.