Study of Streamlines under the Influence of Displacement of Submerged Vanes in Channel Width, and at the Upstream Area of a Cylindrical Bridge Pier in a 180 Degree Sharp Bend

Abstract

In this paper, submerged vanes were placed at the upstream area of a bridge pier located at the 90 degree angle. Then, using the laboratory equipment, a study of flow pattern was conducted throughout the bend, specifically around the pier and submerged vanes. ADV velocimeter was incorporated in order to help measure 3D velocity components. Submerged vanes were installed at distances of 40 and 60% of the channel width from the inner bank at the upstream area of the bridge; while the distance between the vanes and the pier (5 times the pier diameter) and the distance between the vanes themselves (3 times the pier diameter) were held constant during the experiments. The results demonstrated that moving the submerged vanes towards the outer bank created a vortex at a distance of 5 times the pier diameter from the center of the pier in upstream direction at a distance of 33% of the channel width from the inner bank at a height of 6.9 cm, equal to 30 times the flow depth from the bed.