Investigation Dimensions of Separation Zone at Lateral Intake and Flow Pattern in a U Channel Bend with Presence Sill, Dike and Skimming Wall

The percentage of flow diversion is the major cause of the formation of dimensions of separation zone such that with increasing the percentage of flow diversion, width and length of the separation zone decreased in the basic and sill experiments. However, by adding a 10ᵒskimming wall, the changing trend is different. At low percentage of flow diversion, dimensions of the eddy area decreased significantly and it increased with increasing the percentage of flow diversion. However, in general, the simultaneous usage of a 10 degree skimming wall and sill structures compared to basic and sill experiments, dimensions of separation zone in lateral intake decreased and the useful width of outlet flow at lateral intake increased and the separation zone and sediment accumulation at the entrance of lateral channel decreased. By examining the effect of the Froude number of flow (inlet flow) on dimensions of the eddy region, this parameter did not have any significant effect on it and its low impact could be connived. By investigating the width of separation line of flow in the surface and near the bed of channel bend, it was found that the flow diversion rate was the most important factor affecting this hydraulic parameter; since, at surface level of flow with increasing flow diversion ratio, this parameter increases and due to the creation of secondary flow and the change of surface flow pattern under the influence of the simultaneous application of a 10 degree skimming and dike structures, this parameter increases more. However, near the bed, in basic and sill experiments, this parameter increases with increasing flow diversion rate. However, the simultaneous application of 10-degree skimming and sill structures, the width of separation line of flow near the bed reduces by increasing the diverted flow