The Effects of Flow Diversion on Sediments Entering the Intake in 90 Deg. Diversion Angle in Sinus River

The outer part of curve in meandering rivers are suitable places for diversions, as the secondary currents in this locations cause the transfer of the river-bed sediments towards the convex bank. Flow diverting from the outer bend causes the formation of a transverse flow component in depth to surface flow, having an opposite alignment with the secondary current and consequently transferring a part of the sediment load of the river to intake mouth. Besides diversion of the flow will cause the change of the flowing currents pattern in the river bend and decrease the energy of the secondary current in this location, which is important in sediment transportation. This research carried out on the physical model of Sinuosity River. The results has showed that along with low ratios of flow diversion to the intake mouth has a little effect on the secondary current, and also this current causes the repelling of sediments from the outer bend of river. Along with the increase of the ratio of diverted flow, the energy of secondary currents decrease and the ratio of sediment diversion increases. In a ratio of flow diversion, the secondary flow energy fully damped. After that, the sediments entering to the intake mouth has a higher increase compared to the previous situation. The results of Research have showed that the graph curve comparing the changes of diverted sediments to the intake structures, with the flow diversion generally follows the pattern similar to the S shape. The flow depth in the outer part of curve is also the effective parameters on secondary flow. The Increasing of river depth causes intensity in secondary energy and thus decreasing in sediment entering to the intake. In this paper, the effects of flow diversion ratio to sediments ratio entering to the intake structure by considering different flow depths with 90-degree diversion angle was presented.