Investigate the effect of water surface profile of the type of side-weir

The side weirs, also known as the lateral weirs, are widely used in flood channels, irrigation channels, land drainage, and urban sewerage systems by flow diversion or intake devices. There are a lot of studies related to the side weirs located on straight channels. However, the same is not true for curved channels. In this study, the labyrinth weirs have used instead of sharp crested side weirs. A labyrinth weir is defined as a weir crest that is not straight in plan form. The increased sill length provided by labyrinth weirs effectively reduces upstream head for a particular discharge. They can therefore be used to a particular advantage where the width of a channel is restricted and a weir is required to pass a range of discharges with a limited variation in upstream water levels.In this study, a series of laboratory experiments were conducted in order to determine water surface profile at the curved channel for different labyrinth weir apex angles, weir lengths, and crest heights. Rectangular side weirs were tested in order to compare with the labyrinth side weirs. As a result, obtained results were discussed in detail in this study.