The Effect of Distance from Submerged Vanes to the Intake at Different Angles of Vanes on Controlling the Sediment Entering the Intake Branching from a 90° Convergent Bend

In a number of studies, using submerged vanes as a structure to control sediments entering the intake in curved paths has been investigated. Most of these studies were conducted on straight channels, or curved channels with a constant width, and no study has been reported on convergent channels. In convergent bends, the condition of flow is different from bends with a constant width of varied; therefore, the impact of changing the parameters of submerged vanes will be different. This study investigates the effect of changing the distance from submerged vanes to the intake on performance of the vanes at different installation angle of the vanes and at different intake ratios. Therefore, an arch-shaped flume with 90° converging angle, from which an intake channel located at 60° is branched with an angle of 45°, is used and 36 tests are performed at different distances of the vans from the intake and different installation angles for submerged vanes. Using the test results, the volume of the sediments entering the intake and eroded from the convergent channel bed is measured at various situations, and the effect of changing the distance of vanes from the intake is investigated in different intake ratios and different angles. Based on the results, changing the distance from the intake branching from a 90° convergent bend, causes changes in the volume of sediments entering the intake; so, the efficiency of the vanes in controlling the sediments is also changed. According to this study, for?b/H??3 and at a constant angle for submerged vanes, the efficiency is almost constant and for?b/H??4 , as the distance increases, the efficiency is also increased. This effect is more evident at higher intake ratios. Intake ratio of 15% has the maximum efficiency in all tests and as the intake ratio increases, the efficiency of vanes to control the sediments is reduced.