عنوان مقاله [English]
Side weirs are flow-regulating devices commonly encountered in hydraulic engineering. A side weir is an over flow weir framed at the side of a channel, over which lateral outflow takes place when the water surface in the channel rises above the weir crest. They are widely used for flow diversions in irrigation, land drainage, urban sewage systems and also in intake structures. It is essential for hydraulic engineers to correctly predict the weir discharge coefficient, regarding the technical and economical design of side weirs. Although the discharge coefficient for flow over a side weir has been investigated experimentally by many investigators, an overall acceptable formula or a complete analytical solution of the equation governing the flow does not exist. Although sharp crested rectangular side weirs have been extensively studied, there is a lack of information on the other shapes of side weirs, such as labyrinth weirs. In this study the hydraulic characteristics of flow over labyrinth sharp crested side weirs are adapted to formulate the discharge coefficient, based on experimental data and the artificial neural network method. The discharge coefficient (C$_M$) is then related to the main channel upstream; Froude Number (Fr$_1$), weir height to upsteam flow depth ratio (w/y$_1$), weir crest length to channel width ratio (L/B) and the labyrinth weir angle ($delta$). The main objective of this study is to determine C$_M$, based on experimental data, by employing linear and nonlinear regressions and artificial neural network (ANN) approaches. The results have been compared with source data. Comparison of results shows that the ANN method is a good tool for determination of the labyrinth sharp crested side weir discharge cofficient.