Use of conventional flow resistance equations and a model for the Nikuradse roughness in vegetated flows at high submergence

Title:

Use of conventional flow resistance equations and a model for the Nikuradse roughness in vegetated flows at high submergence

Creator:

Gualtieri, Paola, De Felice, Sergio, Pasquino, Vittorio, and Doria, Guelfo Pulci

Identifier:

https://cdk.lib.cas.cz/client/handle/uuid:fda88219-3122-479e-829a-e288735588c7
uuid:fda88219-3122-479e-829a-e288735588c7
doi:10.1515/johh-2017-0028

Subject:

open channel flows, vegetated flows, rigid vegetation, flow resistance, roughness coefficients, and Nikuradse equivalent sand-grain roughness

Type:

article, model:article, and TEXT

Description:

This study examines the problem of flow resistance due to rigid vegetation in open channel flow. The reliability of the conventional flow resistance equations (i.e. Keulegan, Manning and Chézy-Bazin) for vegetated flows at high submergence, i.e. h/k >5, (where h = flow depth and k = vegetation height) is assessed. Several modern flow resistance equations based on a two-layer approach are examined, showing that they transform into the conventional equations at high submergences. To compare the conventional flow resistance equations at high submergences, an experimental methodology is proposed and applied to the experimental data reported in the literature and collected for this study. The results demonstrate the reliability of the Keulegan equation in predicting the flow resistance. Based on the obtained results, a model to evaluate the Nikuradse equivalent sand-grain roughness, kN, starting from the vegetation height and density, is proposed and tested.

Language:

Slovak

Rights:

http://creativecommons.org/publicdomain/mark/1.0/
policy:public

Source:

Journal of hydrology and hydromechanics | 2018 Volume:66 | Number:1

Harvested from:

CDK

Metadata only:

false