3-D Underflow of a Sluice Gate at a Channel Inlet; Experimental Results and CFD Simulations

The underflow of a sluice gate is well known when the gate is set into a channel of the same width (2-D underflow), while no studies are found in the literature when the gate is flush with the wall of the tank or reservoir upstream to the channel (3-D underflow). Experimental and numerical investigations were carried out to study the flow in this case, in a small range of relative openings, considering three wall slopes, and obtaining an equation for the discharge coefficient. Afterwards, numerical simulations were performed by means of a CFD (Computational Fluid Dynamics) model, following the RANS approach and based on a finite-volume computational code. Comparison of experimental and numerical results showed that the simulations predict accurately the flow behaviour; thereafter discharge coefficients in a more extended range of relative openings were computed for use in the practice.