Abstract
This study experimentally and numerically investigates the flow structure to develop scour holes around a dam gate. First, we carry out a movable bed test of the scour. In the test, a weir with a rectangular slit is used to physically simulate the scour induced by sediment releasing through a dam gate. The stereo PIV method is applied to spatially and temporally measure flow velocity fields. Next, we carry out the three dimensional numerical analysis using the bed topography measured in the movable test. The numerical analysis solves the Reynolds-averaged Navier-Stokes (RANS) equations coupled with the VOF method and k-omega SST turbulence closure model. The analytical result is confirmed to agree well with the measurement. The measurement and numerical analysis show a tornado-like vortex in the vicinity of the slit. The vortex is found to highly contribute temporal evolution of the scour hole.
