The effect of labirinth side weirs located curved open channel with live bed on bed topography

Side weirs, also known as lateral weirs, are widely used in irrigation, land drainage, urban sewerage systems by flow diversion or intake devices. Side weirs located on straight channels have attracted considerable interest and research effort. But, It is not available a study for clear water scour of labyrinth side weirs located on curved channels. The present study focuses on the local depth of clear water scour at a side weir intersection located on the curved channel for labyrinth weirs in movable bed at 30° and 150° angle of bed center. Labyrinth weir was used as a side weir. A labyrinth weir is defined as a weir crest that is not straight in plan form. Labyrinth weir apex angle is taken as 90°. Investigations carried out in a curved channel which has movable bed for labyrinth weirs and subcritical flow conditions. As a result of dimensional analysis, it is found that the dimensionless equilibrium scour depth (Hd/p) depends on the dimensionless parameters of velocity V1/Vkr, depth h1/p, lenght L/b and bend angle of ?. The dimensionless equilibrium scour debth (Hd/p) versus V1/Vkr is experimentally investigated for clear water scour (0.5< V1/Vkr<1) at curved channels which has 30° angle. Investigations showed that clear water scour depth increases when the crest depth decrease. Generally, maximum scour created at the end of the downstream of labyrinth weir. With the increase of V1/Vkr., maximum scour depth increased too. Accumulation was shown at the downstream of the weir region. Keywords: Side weir, clear water scour, live bed, curved channel.