Impact of stem flexibility on mean flow and turbulence structure in depth-limited open channel flows with submerged vegetation

This study presents the results of laboratory experiments on depth-limited open channel flow with submerged vegetation. To investigate the impact of stem flexibility on the mean flow and turbulence structures, two flow types with similar drags but with flexible and rigid stems are compared. It is found that the stem flexibility hardly affects the mean flow but increases the peak value of the Reynolds shear stress. In addition, the stem flexibility increases and decreases the streamwise component of the turbulent intensity in the upper and vegetation layers, respectively. However, the stem flexibility increases the vertical component of the turbulent intensity over the whole depth. General profiles of the mean flow, the Reynolds shear stress, and the turbulent intensity are presented. The results of a quadrant analysis and a budget analysis are also provided.