EFFECTS OF UPWARD WEIR WITH AN OPENING ON RIVER BED AND FLOW STRUCTURE

Abstract

 Scouring or depositing downstream of submerged weirs with an opening is a sediment phenomena resulting from the interaction of the three-dimensional turbulent flow field around the structure and the moveable sand bed. This paper presents the experimental study on the downstream channel bed due to weir with an opening, paying attention to the effects of relative overflow depth on local scouring around the structure, sand bars and three-dimensional flow patterns. The experiments were conducted under the clear-water scour condition for an equilibrium scour hole. The experimental results show that local scouring and sand bar development downstream of the submerged weirs decrease with relative overflow depth and turn out strongly paired cellular secondary currents.