Experimental study of Longitudinal Components of Velocity Around Simple Series Spur Dikes

Generally, due to the presence secondary flows in the curvature of the river, the outer wall in the bend is always subjected to degradation and erosion. These streams divert the surface flow lines towards the outer wall and the flow lines close to the substrate to the inner wall. Therefore, studying the flow in the meandering channels in order to prevent erosion is of particular importance. One of the simplest, yet most economic methods to cope with outer wall erosion is the use of spur dike. For this purpose, in this laboratory study, the effect of the presence and absence of series spur dikes on longitudinal velocity components in a channel meandering with sloped erodible wall is investigated. The results showed that the presence of simple series spur dikes cause reduced the flow velocity in the outer wall of the bend. Therefore, the average highest velocity reduction between the second and third spur dikes and the lowest velocity reduction between the third and fourth spur dikes was performed. Also, the studies showed that with the increase of 33% of the discharge, about 5% were added to the performance of the spur dikes in reducing the flow velocity in the outer wall of bend.