Abstract
It is important to predict driftwood motions around hydraulic structures. We proposed a numerical model to simulate driftwood motions based on the coupling of a Euler type three-dimensional flow model and a Lagrangian type two-dimensional driftwood model. Laboratory tests on the driftwood motions in a curved channel and around obstacles are also carried out for obtaining the reference data. The computational results showed that three-dimensional flow features consierabley affect the motion of driftwood in a curved channel. We defined the driftwood Richardson number to consider the three-dimensional behavior of driftwood. The experimental results showed that if the driftwood Richardson number increases, the driftwood shows more three-diemensional behavior and the captureing rate by the obstacle decreases. In addition, we developed a two-way model to consider the drag force from the driftwood toward the flow to simulate the change of flow structures around stacked driftwood.
