An Experimental Study of Current Deflecting Wall-Sill Effect on Sediment Control at Lateral Intake

Abstract

Attention has been paid for many years to the problem of sedimentation in river intakes of irrigation and drainage projects, hydro-electric installations and water treatment plans. One of the methods to control sediment deposition at the entrance of intakes is the application of Submerged Vanes. But their efficiency is restricted to a particular hydraulic condition. In other word at the straight river reach, using submerged vanes in the low value of relative discharge (Qr<0.2) eliminates sediment uptake. Beyond this value, the effectiveness of the vanes reduces. The sediment-control performance of the vanes was enhanced by introducing different structures, modifying vane shape and changing intake geometry. In this research, Current Deflecting Wall-Sill (CDW-Sill) was used as a new method to control sediment at the lateral intake. The sediment-control performance of its various parameters was investigated. Primary and secondary CDW channel width, sill height and the angle of secondary CDW were also investigated using three different relative discharges. The results obtained showed that, when the angle of installation of the secondary CDW is 63 degree the sediment transport was low. The results also showed that up to relative discharge of 0.4, the primary CDW channel width equal to 14 cm has the best performance for different secondary CDW channel widths and eliminates sediment uptake. However increasing the Sill height reduces the performance of CDW-Sill.

Keywords

• lateral intake
• sediment control
• current deflecting wall-sill
• submerge vanes