Abstract: The bulkhead gate of low-head navigation-power junction could not open and close normally because of sediment deposition in the upstream of weir, affecting the inspection and maintenance of sluice gate. In view of this, we established movable-bed physical model and 3D mathematical model of sluice gate to analyze the three dimensional flow field and turbulent kinetic energy distribution in the upstream of the gate. We also observed the scouring effect in the presence of different operation modes of the gate. Results suggest that sediment’s incipient motion is not only related with the flow velocity at gate bottom, but also affected by the flow pattern and turbulence intensity in front of the gate. It is also affected by the increase of turbulent kinetic energy. When the outlets of gate were opened in intervals, vortexes were formed near the gate wall, and complex three-dimensional flow patterns occurred in front of the gate. In this case better scouring effect can be achieved than that when sluice gate is opened continuously.

Key words: sluice gate, sedimentation control, scheduling of erosion and deposition, phreatic flow, erosion mechanism