Experimental Study of Hydraulic Jump on Negative Step by PIV

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Abstract

The hydraulic jump on negative steps forms in stilling basins. In this paper the hydraulic and hydrodynamic behavior of these flows were studied. The experiments were performed in a channel with length:6m depth:0.5m and width: 0.47m. The step heights were 2/5, 4 and 7cm. The varied parameters in hydraulic study were 1. Froud number 2. The ratio of secondary depth to initial depth 3. The ratio of the step height to initial depth. By changing the initial velocity of hydraulic jump, step height and tailwater depth different kinds of hydraulic jumps were formed. For estimating the hydraulic jump shapes different curves were derived. Study about the pressure correction coefficient were done. In hydrodynamic study PIV apparatus was used. This apparatus can measure the velocities in confined surface. In hydrodynamic study the mean velocities and turbulent parameters were investigated. Because of limitations of PIV, the hydrodynamic studies were done only for two different kind of wavy hydraulic jumps and an A jump.

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