Experimental Evaluation of Location and Discharge of Rectangular Free Get on Parameters of Classic Hydraulic Jump

Hydraulic jump formation in stilling basins plays an effective role in energy dissipation of flow, downstream of water structures. A fast jet entrance on hydraulic jump is considered as an important factor in control of hydraulic jump, reduce in the length and secondary depth of the jump and increase in energy loss. In this study, has been studied the effect of rapid rectangular jet collision on four area of jump: before, beginning, middle and end of the jump occur (supercritical area), in the maximum angular displacement of the jump to the upstream, including 3 jet discharges; 2, 2.5 and 3 liters per second, in 6–9.6 Froude number range on the hydraulic jump characteristics., Also, has been evaluated the impact of mentioned options on the jump characteristics. Results showed with collision of jet in the end of hydraulic jump, has been occurred maximum relative displacement to the upstream that has been increased with increasing in jet discharge. In with and without jet conditions, the secondary depth and length of the jump decreased in 39.7 and 55 percent, respectively and energy loss increased to 18%. Bed shear has been increased between 4.2 to 13 times in jet collision conditions to hydraulic jump than without a jet. Jet with maximum angle to jump end section has been had maximum effect on jump length and as a result on length of stilling basin.