Development of Discharge Prediction Model for Trapezoidal Canals using Simple Portable Flume

Consumption of water can be optimized by metering it. In irrigation systems, many lined irrigation canals have trapezoidal cross sections. A simple portable device for measurement of discharge in small trapezoidal agricultural canal has been analyzed in this paper. Measuring flume consists of a cylinder positioned axially in nearly horizontal prismatic trapezoidal channel which can be quickly fixed and removed for short-time use in trapezoidal channels. The cylinder placed in the flow reduces the cross section for flow, thus creating critical flow conditions. In this paper, a new mathematical model has been developed to predict the discharge through a trapezoidal canal by simple cylindrical flume using experimental data available in literature for trapezoidal canal having 1:1 side slope. Dimensional analysis has been carried out to achieve the objective of prediction of more accurate discharge than that calculated by a model available in the literature. The resulting non-dimensional parameters have been used to develop the proposed mathematical model and the results of the proposed model have been compared with the results of the model available in the literature.