Abstract
Laboratory tests were performed for flow over flexible, artificial vegetations attached to the bottom of an open channel. It is found that the Reynolds stress generated at the boundary of the vegetation is transported upward by ejection and downward by sweep, respectively. The organized vortex generated at the top boundary of the vegetation is closely associated with the transport of the Reynolds stress, and honami(waving of the flexible vegetation) is observed to be produced by the movement of the vortex. The periods of vortex generation predicted by a linear stability analysis agree well with the observed periods of honami generation. The instantaneous three-dimensional profile of the organized vortex was measured by employing PIV method and MASCON model, and it was visualized by using Application Visualization System.
