Effect of concentration and grain size of sediment load on hydraulic jump and sedimentation pattern in the downstream of it

Document Type : Original Article

Authors

Abstract
In a laboratory study, concentration and formation of sediment load on the hydraulic jump was studied. Experiments were performed in a stilling basin of rectangular cross-section 0.5 m wide, 0.6 m height and 3 m long. Uniform sands of 0.6, 1.4, 4.1, and 5.6 mm with different concentrations were used in the experiments for various types of hydraulic jump with Froud number ranging from 3 to 9. The results indicate that the sediment size and sediment concentration makes no changes to the incoming super critical flow conditions and therefore, has no effect on the characteristics of the jump (sequent depth, energy loss and length of jump). However, the sediment loads are deposited in the sub critical zone (end of jump) and move downstream as bed load. The motion of the sediment is wave-like with a mild slope at the front followed by a raised bed of nearly uniform thickness terminating into a step. This sand wave performs a control section similar to the end sill in a stilling basin and keeps the hydraulic jump position at the beginning of the basin. The thickness and the position of the front of this sand wave are expressed as a function of upstream Froude number.

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  • Receive Date 06 June 2011
  • Revise Date 18 September 2011
  • Accept Date 19 October 2011