Hydraulic Design of Hollow-Jet Stilling Basins

Hydraulic model and prototype tests made to generalize and prove the hydraulic design of a new type of stilling basic which utilizes the hollow-jet valve for discharge control are described. Dimensionless curves are derived from model data and are used to define the important dimensions of the basin for the usual combinations of valve size, operating head, and discharge. Sample problems are presented to illustrate the use of the design curves and the general hydraulic design procedures. Prototype tests on the Boysen and Falcon Dam stilling basins are described and analyzed to help establish the reliability of the recommended basins. Basin dimensions obtained from individual model tests on six stilling basins are shown to compare favorably with the dimensions obtained from the dimensionless curves and methods given in this paper.