A Study of Flow Structure Topology in the Vicinity of a Concave Bed Sill Using Numerical Model
Volume 8, Issue 2, June 2020, Pages: 26-33
Received: Aug. 10, 2020;
Accepted: Aug. 22, 2020;
Published: Aug. 31, 2020
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Moslem Sohrabi, Water Engineering Department, Shiraz University, Shiraz, Iran
Alireza Keshavarzi, Water Engineering Department, Shiraz University, Shiraz, Iran; Center for Infrastructure Engineering, Western Sydney University, Penrith, Australia
Mahmood Javan, Water Engineering Department, Shiraz University, Shiraz, Iran
Stabilization of the banks and bed of the river is an important problem in river engineering works. River bed scouring is a major environmental problem for fish and aquatic habitat resources. Using a bed sill is one approach that can be used to prevent waterway bed scouring. In this study, a concave bed sill was tested in an experimental program with movable bed condition. In addition to the experimental program, numerical simulations were undertaken to explore the flow characteristic around concave bed sill. In experiment the results showed that most scouring occurred at the channel sides, while deposition occurred in the middle of channel downstream of the concave bed sill. During the experiment two dimensional flow velocity was measured using particle image velocimetry (PIV). It was found that a vortex formed at the sides and downstream of the concave bed sill and then stretched to the middle of the channel. The results also indicated that there was minimum flow vorticity intensity at the center of the channel where deposition occurred. The numerical results were compared with this experimental data to validate the numerical simulations. The numerical results confirmed that for a concave bed sill, similarly a vortex formed at the side of the channel which created the maximum scouring depth at the side wall and with following deposition of sediment particles in the centerline of the channel.
A Study of Flow Structure Topology in the Vicinity of a Concave Bed Sill Using Numerical Model, Hydrology.
Vol. 8, No. 2,
2020, pp. 26-33.
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