Estimate of Zero-Plane Displacement for Open-Channel Flows with Submerged Rigid VegetationSource: Journal of Engineering Mechanics:;2024:;Volume ( 150 ):;issue: 010::page 04024077-1DOI: 10.1061/JENMDT.EMENG-7719Publisher: American Society of Civil Engineers
Abstract: Zero-plane is an important reference level included in the logarithmic velocity profile. The prediction of the zero-plane displacement remains challenging, especially in open-channel flows with submerged vegetation. In this study, we first review the existing formulas for estimating the zero-plane displacement. Then, we conducted a series of laboratory experiments of open-channel flows with submerged rigid vegetation, by varying flow rate, water depth, vegetation density, and stem diameter. By utilizing particle image velocimetry (PIV) technique, the spatio-temporal averaged (double-averaged) flow velocity and Reynolds shear stress profiles were obtained. The data analysis shows that the zero-plane displacement is almost proportional to the surface layer depth for the shallow flow cases. As the flow depth increases, the zero-plane displacement tends to be constant and increases with decreasing vegetation density. This result substantiates the hypothesis that the zero-plane displacement is related to large-scale eddies. Lastly, a heuristic model is developed to explain possible variations of the large-scale eddies, which yields a formula for predicting the zero-plane displacement for flows subjected to submerged rigid vegetation.
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contributor author | Ran-Ran Mao | |
contributor author | Ning Liu | |
contributor author | Nian-Sheng Cheng | |
date accessioned | 2024-12-24T10:25:49Z | |
date available | 2024-12-24T10:25:49Z | |
date copyright | 10/1/2024 12:00:00 AM | |
date issued | 2024 | |
identifier other | JENMDT.EMENG-7719.pdf | |
identifier uri | http://yetl.yabesh.ir/yetl1/handle/yetl/4298905 | |
description abstract | Zero-plane is an important reference level included in the logarithmic velocity profile. The prediction of the zero-plane displacement remains challenging, especially in open-channel flows with submerged vegetation. In this study, we first review the existing formulas for estimating the zero-plane displacement. Then, we conducted a series of laboratory experiments of open-channel flows with submerged rigid vegetation, by varying flow rate, water depth, vegetation density, and stem diameter. By utilizing particle image velocimetry (PIV) technique, the spatio-temporal averaged (double-averaged) flow velocity and Reynolds shear stress profiles were obtained. The data analysis shows that the zero-plane displacement is almost proportional to the surface layer depth for the shallow flow cases. As the flow depth increases, the zero-plane displacement tends to be constant and increases with decreasing vegetation density. This result substantiates the hypothesis that the zero-plane displacement is related to large-scale eddies. Lastly, a heuristic model is developed to explain possible variations of the large-scale eddies, which yields a formula for predicting the zero-plane displacement for flows subjected to submerged rigid vegetation. | |
publisher | American Society of Civil Engineers | |
title | Estimate of Zero-Plane Displacement for Open-Channel Flows with Submerged Rigid Vegetation | |
type | Journal Article | |
journal volume | 150 | |
journal issue | 10 | |
journal title | Journal of Engineering Mechanics | |
identifier doi | 10.1061/JENMDT.EMENG-7719 | |
journal fristpage | 04024077-1 | |
journal lastpage | 04024077-12 | |
page | 12 | |
tree | Journal of Engineering Mechanics:;2024:;Volume ( 150 ):;issue: 010 | |
contenttype | Fulltext |