Abstract
A lot of aquatic plants are observed in actual rivers and they have a potential to improve water quality. A large-scale coherent vortex is generated near the vegetation edge, which dominate the momentum and scalar transport. Thus, estimating the flow resistance of vegetated flows is of great importance in river management. In such vegetated open-channel flows, both the geometry of the vegetation elements (shape, size, flexibility and vegetation density) and turbulence characteristics affect the hydrodynamic resistance significantly. However, any important relation between the vegetation motion and the flow resistance property have not been yet established. Therefore, in the present study, we highlighted these important topics and measured the instantaneous velocity structure and coherent motion in open-channel flows with flexible vegetation by using PIV-PTV technique. As the results, the hydro-mechanic interaction between the flow and flexible plant motion was revealed.
