Experimental and simulation analysis of flow patterns and energy dissipation through sluice gates in a U-shaped channel

Abstract

The vertical U-shaped gate holds significant potential for widespread application in flow control within U-shaped channels, as it eliminates the necessity for constructing auxiliary hydraulic structures. The boundary conditions associated with the U-shaped gate are complex, offering distinctive hydraulic features. In this study, the hydraulic characteristics of a vertical U-shaped gate have been investigated by model test and numerical simulation on a U-shaped channel under different flow rates, and the hydraulic evolution process was analyzed. The results show that the minimum relative error of discharges is 0.4%, so the numerical simulation can accurately describe the hydraulic performance of the vertical U-shaped gate. The flow generates a contracted cross-section and presents rhomboid water waves with a ‘hump-like’ convex structure after passing the U-shaped gate, accompanied by large kinetic energy dissipation. The gate opening exerts notable influence on the free surface width. The width of the first contraction section increased by 53.88% as the gate opening ranged from 2.5 to 5.5 cm with a flow rate of 8.24 L/s. The power function relationship of upstream flow Froude number, the width of free surface and energy loss is established. The results are helpful for engineering designing and operation management of a U-shaped gate. HIGHLIGHTS Indoor experiments and numerical simulation are used to investigate the hydraulic performance of a U-shaped gate.; Water flow presented rhomboid-shaped water wave downstream for U-shaped gates.; Diamond-shaped water waves will result in kinetic energy dissipation.; The value of free surface width can estimate the kinetic energy loss.; The width of the free surface and the energy loss present a power function relationship.;

Keywords

• energy loss
• hydraulic performance
• numerical calculation
• rhomboid water wave
• u-shaped sluice gate