Variations of Hydraulic Jump Characteristics Due to Different Sill with Slot Layouts
Mahmoud A. Refaey Eltoukhy *
Faculty of Engineering, Benha University, P.O.Box 11629, Shoubra, Egypt
Wail A. Fahmy
Faculty of Engineering, Benha University, P.O.Box 11629, Shoubra, Egypt
*Author to whom correspondence should be addressed.
Abstract
Downstream many hydraulic structures such as dams, barrage sluice gate etc, changing water flow from supercritical to subcritical flow causes formation of hydraulic jump. The formed hydraulic jump dissipates excess energy of flowing water. This paper carried out experimental runs to study the effect of sills with slot on the hydraulic jump characteristics. The considered hydraulic jump characteristics were the jump sequent depth, jump height, jump length, and energy losses through the jump. In these experimental runs, three sill parameters, which are sill relative slot area, relative sill height, and relative sill distance were used to study their effects on the hydraulic jump characteristics. Five relative slot areas with values of 0 (solid sill), 25, 50, 75, and 100% (no sill), four relative sill heights, of 0 (no sill), 0.75, 1.0, and 1.5 and three relative sill distances were used to show the effect of each parameter on the hydraulic jump characteristics. Results showed that the hydraulic jump sequent depth, height, and energy losses have directly proportional relation with relative sill height but inversely proportional relation with sill relative slot area and relative sill distance. Opposite results were obtained for the jump length. The results were translated into group of curves and equations to obtain any jump characteristic for given sill relative slot area, relative sill height, and relative sill distance. Also, empirical computational models were developed using Buckingham’s π-Theorem to calculate any hydraulic jump characteristic for given conditions.
Keywords: Hydraulic jump, sequent depth, controlled jump, sill parameters energy losses