simulation of flow features in the face of tainter and sluice gate flow measurement structures

Gates are structures that permit water flow underneath the gate. they are important water-management structures and require careful design by engineers. the aim of this research is to numerically evaluate the effect of a sill on the hydraulic flow characteristics through sluice and tainter gates using the volume of fluid (vof) method. sills with various geometric characteristics were simulated. the findings indicated that the rng turbulence model had the highest accuracy compared to k-ε, k-ω, and les. the discharge coefficient (cd) with a sill is higher than without a sill. among the investigated sills, the semicircular sill cd is greater than that of the rectangular one. in addition, the cd of the tainter gate exceeds that of the sluice for regardless of whether a sill is used. increasing the thickness of the sill leads to increases in the shear stress of the flow, and consequently, the flow rate decreases. the cd with a gate with a sill always exceeds the value without a sill. on the other hand, the cd increases with the increase of the sill height up to a certain level and then decreases thereafter.