Abstract
Planform vortices are observed in a flow field where the water depth increases in streamwise direction as seen in a large scour hole in the Kiso River, but the generation mechanism of such planform vortices are still not clear. In this study, 3-D numerical analysis was performed in a laboratory open channel with one-sided pool and the reproducibility of the characteristic flow structure with a planform vortex was confirmed. In order to investigate the topographic condition for the generation of the planform vortex, a PIV experiment was conducted in an open channel with laterally uniform 2-dimensional pool. As a result, a pair of planform vortices were generated near both the side wall and the accelerated flow was concentrated on the center of the channel. The observed flow structures were well reproduced by the 3-D numerical model and the generation condition and flow structures are analyzed.
