Abstract
In this study, the local scour behind the weir due to overflows was calculated using three-dimensional multiphase numerical model (MICS). In this method, the shape of a gravel particle is represented by multiple tetrahedron elements, and collisions between gravel particles are treated by the contacts of the multiple collision detection spheres placed inside of the gravel particle. Fluid forces acting on the gravel particle are calculated from the pressure-gradient and viscous terms in the momentum equations for multiphase fields. As a result of the numerical experiments, movements of 14,400 gravel particles due to the overflow were predicted and local scour arose behind the weir. In addition, the scour depth and area become larger when the flow rate is large.
