Author(s): Amir Ahmad Dehghani; Masoud Ghodsian; Seyed Ali Akbar Salehi Neyshabouri; Mehdi Shafieefar
Linked Author(s): Seyed Ali Akbar Salehi Neyshabouri
Keywords: Bed topography; 180_o_Channel bend; Lateral diversion; Movable bed; Secondary flow
Abstract: The mechanism of flow and sediment transport in channel bend is much more complex when the outer bank of the bend is used for lateral diversion. Because of secondary current, the sediment moves away from outer bank toward inner bank and therefore outer bank of the bend is one of best positions for lateral diversion. The flow characteristics and bed topography of channel bend without lateral diversion have been studied by previous researchers, however there is no any information is available on the bed topography of channel bend due to lateral diversion. In this paper, experimental results of bend characteristics with lateral diversion are presented for steady condition with movable bed. Also, the longitudinal and transverse variations of bed profiles at various sections of channel bend are compared. The results show the oscillatory behavior of bed topography and formation of the point bar and scour hole. It was found that the rate of bed deformation is very high at the beginning of experiment, and by increasing the time, this rate becomes slow due to the counteracting effect of gravity force in the lateral direction.
Year: 2005