Somayeh Emami; Omid Jahandideh
Abstract
Weirs are generally used for flow diversion, flood passage, and water level control in dam reservoirs, rivers, and open channels. The Crump weir with its special design is one of the short-edge weirs, which is used to measure the discharge of channels. In the present study, the discharge coefficient ...
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Weirs are generally used for flow diversion, flood passage, and water level control in dam reservoirs, rivers, and open channels. The Crump weir with its special design is one of the short-edge weirs, which is used to measure the discharge of channels. In the present study, the discharge coefficient on the Crump weir was modeled using FLUENT software for different slopes and heights. The flow field on the Crump weir was performed using three turbulence models RSM, k-ε RNG, and k-ω in two dimensions and a multiphase VOF model. The flow conditions were considered as subcritical, turbulent, and falling flow in all cases. The efficiency of FLUENT software was evaluated using statistical indicators, including correlation coefficient (R2), root mean square error (RMSE), and mean absolute error (MAE). The results show that the FLUENT software has good efficiency in modeling the flow on the crump weir by obtaining RMSE=0.93 and MAE=0.7. The results showed that with the increase of the weir height at a constant discharge, the discharge coefficient decreases. The discharge coefficient in the Crump weir with a height of 0.15m had the highest value. There is a direct relationship between the increase in the downstream wall slope of the weir and the discharge coefficient so with the increase in the downstream wall slope, the discharge coefficient increases.