Investigation the Effect of Well Shape on Performance of Fusegate Weir

In the current study, the effect of well shape (rectangular nose, round nose and sharp nose) on the hydraulic performance of standard fusegate model WLH (Wide valve Low Head) and NLH (Narrow Low Head) was investigated. These fusegates were made in 16.7 and 25 cm heights with five different heights of wells, respectively. Experiments were carried out in a laboratory flume of 12 meters in length, 0.5 meters in width and 0.7 meters in height. In total 331 data were recorded and using it, the values of the flow coefficient for the fusegate were calculated. Using 80% of the data, appropriate relationships were presented for estimating the discharge coefficient, and then these relationships were validated using the remaining 20% of the data and the RMSE evaluation criterion. Results showed that the height and shape of the well have no considerable effect on the discharge coefficient of the fusegate. At the same height of the well, the water rises more when it collides with the rectangular nose well and enters the well sooner, but when it collides with the sharp nose well, it splits and is directed to the sides along the downstream and enters the well later. Thus, at a certain height of the well, the overturning discharge of the fusegate with the rectangular well is lower than the others, and the rounded nose well is in the next order.