Abstract
This study deals with a numerical method which allows for the hydrodynamic force acting on a natural stone in open-channel flows. The numerical accuracy was verified in comparison with experimental results. We conducted three cases of experiments with a model stone made by reinforced plastic, adjusting the flow discharge in a straight rectangular open-channel with a flat bed. In those experiments, we measured not only the drag force and lift force, but also the vertical velocity distribution of streamwise flow approaching in front of the stone. Addtionally, we carried out numerical simulations for evaluating the forces acting on the numerically-modelled stone. Namely, we approximately generated the numerical stone using tetrahedron elements in terms of stone shape, imitating the actual model stone. For the computation model, we considered the mechanical interactions between fluid motions and the modelled stone which behaves as a rigid body. Results showed that numerical data related to the hydrodynamic forces are consistent with the expmerital measurements. Therefore, the validity of our computation method was demonstrated.
