Dispersion in Submerged Vegetated Flow with Coherent Vortices
Publication: Journal of Hydrologic Engineering
Volume 17, Issue 1
Abstract
The presence of submerged vegetation divides flow velocity vertically into overflow and vegetation velocities connected by a strong shear. In addition, the flow structure exhibits periodic oscillations at the interface called Kelvin-Helmholtz vortices. The entire flow is divided into a combined vortex-overflow region that covers the overflow and upper part of the vegetation and a lower vegetation region below the vortices. A closed-form solution for longitudinal dispersion in this flow field is derived, which is an addition of the steady flow dispersion in the two regions and the dispersion caused by inefficient exchange between the two regions. The shear velocities in both the regions are modeled by using power law, whereas the vortices are modeled by the periodic components of the combined vortex-overflow stream function. The proposed dispersion model depicts shear-induced steady flow dispersion and vortex-induced dispersion caused by the inefficient exchange and shows reasonable agreement with past data.
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Information & Authors
Information
Published In
Journal of Hydrologic Engineering
Volume 17 • Issue 1 • January 2012
Pages: 1 - 9
Copyright
© 2012 American Society of Civil Engineers.
History
Received: Feb 3, 2009
Accepted: Apr 6, 2011
Published online: Dec 15, 2011
Published in print: Jan 1, 2012
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