An investigation of the hydrodynamics of flow at the labyrinth side weirs in the movable bed rivers

Side weirs, also known as lateral weir, are widely used in flood, irrigation, land drainage and combined urban sewer systems for flow diversion or intake structures. It is known that the rivers in nature have movable beds however; there is just limited research information about the side weirs located on the movable beds. Local depth of scour around the triangular labyrinth side weirs located on the straight and rectangular channel having movable bed was investigated experimentally for steady and free overflow conditions. A labyrinth weir is defined as a weir crest that is not straight in plan form. Labyrinth weir apex angle was taken as 90⁰. As a result of dimensional analysis, it was found that the dimensionless equilibrium scour depth (Hde/p) depends on the flow intensity (V1/Vkr), dimensionless depth (y1/p), dimensionless lenght (L/B) and side weir apex angle (θ). The variation of dimensionless scour depth (Hd/p) with "V1/Vkr" is experimentally investigated for movable bed scour conditions (1