Turbulence Effects of Aquatic Plants in Open Channels

Abstract

Open channel flows are studied for channel beds covered wholly or partially with rigid aquatic plants. The aquatic plants for the wholly covered channel beds are simulated by cylinders of the same height and diameter covering the bottom part of channels. In the other case, the aquatic plants for the partially covered channel beds are simulated by the same kind of cylinders, set at three kinds of spacing in the near-bank region. Based on turbulence measurements in laboratory flumes with simulated aquatic plants, the turbulence structure of the flows in the vertical and lateral directions are investigated. In these experiments the aquatic plants largely affected the turbulence structure of the flow. A theoretical method can be a tool to predict the effects of the aquatic plants on the retardation of the flow.