Numerical Investigation on Effective Parameters on Hydraulic Flows in a Sluice Gate with Sill on Free-Flow Condition

The presence of a sill under the sluice gate is one of the solutions to control the flow rate. This study was conducted to numerically investigate the discharge coefficient (Cd) of sluice gates with different heights and widths of sills in free flow conditions. The simulations were performed using FLOW-3D software. Results show that Cd increases as the gate opening decreases. Also, results showed that reducing the gate opening from 5 cm to 2 cm increases the Cd in the gate with sill by 9% compared to the non-sill gate. Discharge coefficients with 1 cm and 4 cm sills, compared to the non-sill condition were estimated at 1.5% and 18%, respectively. Examination of sill width changes showed that decreasing the width reduces the discharge coefficient by reducing the amount of velocity and flow pressure along the sill sides. The effects of three parameters of the gate opening, sill height, and sill width were compared. The results showed that increasing the sill width compared to the two mentioned parameters has the maximum increase in the Cd.