Investigation Experimental of weir discharge coefficient in the lateral intake located at curve channel

Application of lateral intakes has been always considered by human for water supply. The lateral intake is a structure constructed to divert the water from Meandering Rivers for irrigation, storage and industrial purposes, etc. Given that rivers have curvatures in most of their path and also due to secondary flows, external shore of river bend is a good place for intake. An influent weir is constructed at the beginning of intake channel to control the inflow to lateral intake. In this study, to examine the influent weir discharge coefficient to the lateral intake at the river bend, some experiments were conducted in a laboratory rectangular channel with a 180-degree arc made of Plax glass in clear water conditions and without sediments. In these experiments, the effect of variables to the height of the weir at the upstream depth, catchment area at the bend and the Froude number on discharge coefficient of the flow at the inlet span of the intake was studied. The results show that if the bottom sediments inlet to the intake was not proposed, by increasing the Froude number and weir height ratio to the upstream depth, the intake discharge coefficient decreases. The maximum intake discharge coefficient was also observed at 70 and 100 degrees, and at least in 30 and 120 degrees.