EXPERIMENTAL STUDY ON HORIZONTAL VORTEX IN MEANDERING COMPOUND OPEN-CHANNEL FLOW WITH MULTI-LAYER SCANNING PIV

Abstract

It is needed to reveal coherent horizontal vortices in meandering compound open-channel flows for predicting the transport and distribution of suspended sediment in actual rivers. However, in previous studies, flow-visualization techniques such as PIV and PTV, have not sufficiently been applied to such flows, and thus, there is almost no detailed information on coherent turbulence in meandering compound open-channel flows. Therefore, in this study, we conducted innovative flow-visualization measurements by using a multi-layer scanning PIV system, and analyzed instantaneous velocity vectors on horizontal planes at several different elevations simultaneously. As the results, the time-space correlations between the different elevations, the vortex-core motion and POD properties were revealed in the meandering compound open-channel flows.