Abstract

Sedimentation in river intakes causes many problems such as reduction of system delivery efficiency and increasing of maintenance costs. Several methods have been introduced for sediment control in river intakes and an effective method for preventing sediment entering into river intake is submerged vanes. The overall effective strategy for reducing bed sediment transport into the intake should be based on reducing the strength of the secondary flow and limiting the extent of the dividing stream surface at the bed. The objective of this study is to explore the possibility of applying an effective structure to control bed load sediment at the river intake. Current Deflecting Wall-Sill (CDW-Sill) was employed as a new method of controlling bed load sediment at river intake. The experiments were carried out under the live bed condition at the flow intensities (V/VC) of 1 and 1.1 for five hours. The relative discharges of the flow into the diversion which is defined as a ratio of diversion unit discharge to main channel unit discharge (qr) were equal to 0.2, 0.4 and 0.6. The results showed that the performance of the CDW-Sill, up to the available specific discharge ratio of 0.6, was better than the submerged vanes. However up to specific discharge ratio of 0.4, the width of primary CDW channel equal to 14 cm had the best performance which eliminated the sediment uptake.