Interaction of a Turbulent Round Jet with the Free Surface
MICHIGAN UNIV ANN ARBOR DEPT OF AEROSPACE ENGINEERING
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An experimental study of the interaction of an underwater turbulent round jet with the free surface was conducted. Flow visualization, surface curvature measurements and hot film velocity measurements were used to study this flow. It is shown that surface waves are generated by the large scale vortical structures in the jet flow as they approach the free surface. These waves propagate at an angle with respect to the flow direction. The propagation angle increases as the strength of the interaction is increased by increasing the momentum flux of the jet or reducing the distance of the jet to the free surface or both. Propagation of these waves in the flow direction is suppressed by the surface current produced by the jet. Far downstream the surface motions are caused by the large scale vortical structures interacting directly with the surface. The fundamental scaling parameters of the free-surface jet have been determined. The velocity scale is the velocity obtained from the combination of jet momentum, density and depth of the jet and the length scale is the distance of the et to the free surface. It is shown that the centerline velocity decay when scaled with these parameters collapses to a universal curve for different depths of the jet.
- Fluid Mechanics