Submerged Radial Hydraulic Jump

A slight flaring of the side walls of the stilling basin can be advantageous in reducing the exit velocities. The hydraulic jump in such a stilling basin is referred to as a radial hydraulic jump. When the sluice gates discharge directly to the stilling basin, a submerged radial hydraulic jump will probably occur. An experimental study produced surface profiles, bed pressure and length characteristics for the submerged radial jump. A fourth-degree polynomial was used to describe the surface profile. The submerged radial jump lengths were found to be from 50% to 70% of the corresponding submerged rectangular jump lengths. Improved energy dissipation is also characteristic of the radial jumps. The model consisted of a 1.0-m long stilling basin with a total divergence angle of 13.5? located downstream a sluice gate. A theoretical equation is proposed to describe the relationship among: gate submergence, exit depth, initial depth, initial Froude number and basin divergence.