Investigation of spur dike and submerged vanes on dividing streamline at lateral intakes

The dividing streamline can be defined as a portion of flow from main canals that entering intake channel. The dividing streamline extends far out into the main channel near the bed and stays near the main channel wall at the water surface and so a large portion of bed load can enter to the lateral intake channel. In this study four experiments include: submerged vanes with intake, spur dike with intake and using simultaneous spur dike submerged vanes in front of intake and without any structure in front of intake channel. Results showed that by using a set of vanes, the dividing to streamline move near intake channel near the bed and extend far out at the water surface. At discharge ratio of 0.18, width of the separation zone is 34 percent of main channel width and by using simultaneous spur dike and submerged vanes, it decreases to 4 percent. Furthermore, by adding a single spur dike to the set of vanes, the efficiency of vanes increases and also due to reducing the dividing streamline expansion to the main channel, sediment movement to lateral intake decreased.