Effect of a Submerged Vane-Field on the Flow Pattern of a Movable Bed Channel with a 90° Lateral Diversion

Water

Gökçen Bombar¹  Joana Baltazar²  AntónioHeleno Cardoso²  Elsa Alves³ 

[1] Civil Engineering Department, İzmir Katip Çelebi University, 33/2, İzmir 35620, Turkey;Civil Engineering Research and Innovation for Sustainability (CERIS), Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisbon, Portugal;Hydraulics and Environment Department, Laboratório Nacional de Engenharia Civil (LNEC), 1700-066 Lisbon, Portugal;

关键词: diversion;    sediment transport;    bed equilibrium;    submerged vanes;    three-dimentional flow;    flow separation zone;   

DOI  :  10.3390/w13060828

来源: DOAJ

【 摘 要 】

This laboratory study focused on the effect of a submerged vane-field on the flow pattern and bed morphology near and inside the entrance reach of a movable bed 90° lateral diversion. The system was modelled under live bed conditions for a water discharge ratio of ≈0.2. Two experiments were run until bed equilibrium was reached: with and without a vane-field installed close to the diversion entrance to control the transfer of sediments into the diversion channel. The equilibrium bed morphology and the associated 3D flow field were measured in great detail. The bed load diverted into the diversion was reduced by approximately one quarter due to the action of the vane-field. The vanes prevented the formation of the diversion vortex in the main channel, upstream of the diversion’s entrance, thus contributing to that decrease. They also created a main channel vortex that started at the most upstream vanes and further decreased the amount of bed load entering the diversion. The flow separation zone inside the diversion was larger with vanes, but conveyance was balanced through a slightly deeper scour trench therein. The flow structures described were confirmed through the measurements of the turbulent kinetic energy.

【 授权许可】

Unknown