FREE SURFACE FLUCTUATIONS AND MOMENTUM TRANSPORT IN OPEN CHANNEL FLOW WITH SUBMERGED VEGETATION

Abstract

Laboratory experiments were conducted using two-components electromagnetic current meter and particle image velocimetry (PIV) to clarify the interaction between main flow and flexible artificial vegetation, which was attached to the central bottom and sidewall of an open channel. Experimental results showed that in the main flow region under equilibrium horizontal components of secondary currents pointed in the direction toward the vegetation zone near the bottom, and in vegetation zone vertical components directed the upward. Furthermore, horizontal periodical components of velocity variations have strong correlation with water surface fluctuations and activated the momentum transport from main flow region to vegetation zone.