Velocity Field and Turbulence Structure around Spur Dikes with Different Angles of Orientation under Ice Covered Flow Conditions
School of Engineering, University of Northern British Columbia, Prince George, BC V2N 4Z9, Canada
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Academic Editors: Yong G. Lai and Achim A. Beylich
Water 2021, 13(13), 1844; https://doi.org/10.3390/w13131844
Received: 10 May 2021
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Revised: 25 June 2021
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Accepted: 27 June 2021
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Published: 1 July 2021
(This article belongs to the Special Issue River Hydraulics under Ice-Covered Flow Conditions)
Spur dikes are well-known structures that are widely used in rivers and coastal regions. Depending on their types, sizes, and orientation angles, spur dikes can substantially change flow characteristics. Results of previous studies indicate that the presence of an ice cover in rivers can cause complicated flow structures. The present experimental study investigates velocity fields and turbulence structures in the vicinity of spur dikes under ice cover with different roughness coefficients. The spur dikes were set up at the following three angles of orientation, 90°, 60°, and 45°. Our results show that the strongest velocity fluctuation occurs immediately above the scour hole surface and very close to the dike tip. The increase in the dike angle toward upstream, the velocity component values increase, leads to a larger scour hole. Results show that an increase in dike angle of each 10° (from 45° to 90°) increases the scour depth between 5% and 10%, depending on flow conditions. Furthermore, the increase in the cover roughness coefficient and the blockage ratio of a spur dike leads to a further increase in turbulence kinetic energy and 3D velocity components values. The findings of this study imply that the appearance of an ice cover can increase turbulence intensities up to nearly 30%.
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Keywords:
spur dike; ice cover; acoustic doppler velocimeter (ADV); instantaneous velocity component; turbulence intensity; local scour
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MDPI and ACS Style
Jafari, R.; Sui, J. Velocity Field and Turbulence Structure around Spur Dikes with Different Angles of Orientation under Ice Covered Flow Conditions. Water 2021, 13, 1844. https://doi.org/10.3390/w13131844
AMA Style
Jafari R, Sui J. Velocity Field and Turbulence Structure around Spur Dikes with Different Angles of Orientation under Ice Covered Flow Conditions. Water. 2021; 13(13):1844. https://doi.org/10.3390/w13131844
Chicago/Turabian StyleJafari, Rahim, and Jueyi Sui. 2021. "Velocity Field and Turbulence Structure around Spur Dikes with Different Angles of Orientation under Ice Covered Flow Conditions" Water 13, no. 13: 1844. https://doi.org/10.3390/w13131844
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