Interaction between submerged vanes for sediment management

Abstract

A new approach to analyze the interaction among a row of submerged vanes is described. Submerged vanes are small foil-like elements mounted vertically on the channel bed to modify the flow pattern and the sediment distribution within its cross section. Usually a number of vanes are arranged in a row to widen the affected area. Due to the interaction among the vanes, the sediment control capability of a vane system diverts from simple superposition of individual vanes.A new methodology is developed to model this interaction. The results show that the sediment management capacity of a vane system comprising three vanes in a row decreases when the vane spacing is reduced. Upon these three vanes, the declination of the inner vane is especially evident. When the spacing between the vanes is smaller than about 0.6 vane lengths, the center vane has nearly half function left. An investigation on vane systems comprising different numbers of vanes shows that their efficiency decreases due to the interaction among the vanes, while the performance of a vane system increases with more vanes in a row.