Abstract
The Lagrangian concept of the discretization of the Navier-Stokes equation, or the MPS method, which is generally called the Particle Method, is applied to the unidirectional flow with the periodic boundaries at its upstream and downstream ends. The MPS method is less affected by the numerical diffusion due to the convection term than the Eulerian methods, namely it has a superiority in the accurate calculation of the complicated behavior of water surface. The characteristics of the pool-and-weir fishway is investigated by using MPS method as the typical flow situation with the complicated behavior of water surface and the applicability of the periodic boundary condition. The plunging flow and the streaming flow, which are known as the two sub-modes of the flow in the pool-and-weir fishway, are reproduced well. The complicated unsteady behavior of the flow under the plunging flow mode is numerically investigated by the present simulation.
