抄録
For flexible vegetation flow, the passage of the coherent vortex causes a local depression in the canopy and the waving motion is called Monami. It is well known that the Monami motion has significant heterogeneity and the Monami scale appears to be a function of the vortex size. However, no detail information on the Monami scale exists (streamwise and lateral direction). So, in the present study, simultaneous measurements of two-line flexible vegetation elements are conducted by using 2-color PTV. The results suggested that the flexible vegetation element in each sub-channel exhibits a periodic sequence of Sweeps and Ejections.