Effects of Vegetation Density on Coherent Structure inFlexible Vegetated Open-Channel Flow

摘要

It is necessary in river environment and hydraulic engineering to investigatethe hydrodynamic properties in vegetated open-channel flows. It is often observedthat the downstream advection of the Kelvin-Helmholtz vortices generates thecoherent waving motion of plants, which is called the "Monami" phenomena inaquatic canopy flow. These "Monami" motions dominate the vertical momentumtransport and scalar transport into the aquatic canopies. Therefore, in the presentstudy, the instantaneous measurements of water velocity and vegetation motion wereconducted successfully by PIV & PTV. As the results, we revealed the relationbetween the turbulence structure and the occurrence of Monami phenomena.