Wave structure in the radial film flow with a circular hydraulic jump

A circular hydraulic jump is commonly seen when a circular liquid jet impin ges on a horizontal plate. Measurements of the film thickness, jump radius and the wave structure for various jet Reynolds numbers are reported. Film thickness measurements are made using an electrical contact method for regi ons both upstream and downstream of the ' jump over circular plates without a barrier at the edge. The jump radius and the separation bubble length ar e measured for various flow rates, plate edge conditions, and radii. Flow v isualization using highspeed photography is used to study wave structure an d transition. Waves on the jet amplify in the film region upstream of the j ump. At high flow rates, the waves amplify enough to cause three-dimensiona l breakdown and what seems like transition to turbulence. This surface wave induced transition is different from the traditional route and can be expl oited to enhance heat and mass transfer rates.