Effect of End Step Shape in the Performance of Stilling Basins Downstream Radial Gates

Stilling basins are in common use when designing heading-up hydraulic structures such as barrages, dams, weirs …etc. This research paper investigates the effect of stilling basin shapes with different heights of end step on the characteristics of submerged hydraulic jump and the energy dissipation downstream the radial gate. Generally, this research investigate the main characteristics and parameters of the submerged hydraulic jump such as; the vertical velocity distribution, the near bed velocity decay along stilling basin, and the stability of bed protection downstream the stilling basin. In the present research paper, these characteristics will be tested in a pool-type stilling basin with end steps downstream (DS) the radial gate of new spillway of Assuit Barrages. The experimental program was conducted on a re-circulating flume with 1.0 m wide, 26.0 m long and 1.2 m deep, with discharges range from 40 to 190 l/s. Statistical equation was developed to correlate the length of submerged jump with the other independent parameters. Finally, clear matching of results from the length of jump and velocity analysis was obtained.