Numerical study of flow in open-channel bends partially occupied with vegetation

Abstract

Abstract Curved channel is a common topographic pattern in rivers. Its water flow characteristics have an important influence on the ecological environment of rivers and the construction of water conservation projects. In this work, five bending angles of the river at 0°, 45°, 90°, 135° and 180° are studied by Reynolds stress turbulence model. The simulation results showed that:(1)An increase in the bend angle of the river will reduce the flow velocity of the concave bank and increase the flow velocity of the convex bank.(2)When water flows through meandering rivers with vegetation on the concave bank, the main flow area gradually shifts from the convex bank to the boundary between non-vegetated and vegetated areas, and this shift velocity increases with the angle of curvature.(3)The turbulent kinetic energy of the vegetated region is much larger than that of the non-vegetated region, and the energy at the exit of the curve increases significantly.