Discharge measurements in sewers using combined weir-gate device

In this paper a combined weir-gate device was tested experimentally in circular sewer for flow measurements. The device was tested in two different locations. One at the end of the system in which free fall is exist and the other is within the system. In both locations flow released from the gate is under free flow conditions. Different weir gate dimensions were tested. Results showed that location plays important role on discharge coefficient and that the discharge coefficient correlates well with the flow parameters, gate opening and weir height. Equation were developed for the device for both locations and agreements with experimental data was achieved.