Effect of Distance of the Submerged Vanes from the Outer Bank on Sediment Movement within 180° Bend

Abstract

A small aspect ratio of submerged vanes when used near the outer bank at the angle of attack between 10° to 20° and at the initial height above the bed between 20-40% of flow depth is considered one of the most successful river training structures. Vanes when located within the bends of river, produces helical swirls at inverse action with the centrifugally secondary current action. Accordingly, its existence leads to mitigate the influence of the secondary current, thus reducing the outer bank erosion. The present study aims to investigate the effect of distance which measured from the outer bank (δb) on the hydraulic performance of vanes when it arranged at a specified configuration within 180° bend. As a result, when the submerged vanes have been installed at δb/b = 0.25 within the third to the fifth sectors of bend and δb/b = 0.1 within the sixth sector at a zigzag pattern led to lesser outer bank scour with the Percentage Improvement (PI-indicator) equal to 72.71%.