摘要：Labyrinth weirs are effective and economic solutions where there are width and water level limitations at the upstream of the weir construction site. Due to its increased crest length within a given width, a labyrinth weir can pass a higher flowrate through its zigzag section (at the same hydraulic load) compared to straight weirs. The main hypothesis in the development of weirs is that the discharge capacity over the weir can be increased by increasing the length of the crest within a given transverse distance. This study examines the discharge coefficient of single-cycle and double-cycle arch plan weirs under different hydraulic heads. The obtained results showed that increasing the weir hydraulic head (Hd/P) from 0.03 to 0.65 would decrease Cd by about 52%. In addition, the discharge coefficient in the double-cycle weir was considerably greater than that in the single-cycle weir, with the Cd in the former being 57% greater than that in the latter under the most favorable conditions.
