Assessing theoretical flow velocity profile and resistance in gravel bed rivers by field measurements

Porto, P.

Risultato della ricerca: Article

1 Citazione (Scopus)

Abstract

Previous studies showed that integrating a power velocity profile, deduced applying dimensional analysis and the incomplete self-similarity condition, the flow resistance equation for open channel flow can be obtained. At first, in this paper the relationship between the Gamma function of the power velocity profile, the channel slope and the Froude number, which was already empirically introduced in a previous paper, is now theoretically deduced. Then this relationship is calibrated using the field measurements of flow velocity, water depth and bed slope carried out in 101 reaches of gravel bed rivers available by literature. The proposed relationship for estimating Gamma function and the theoretical flow resistance equation are also tested by an independent dataset of 104 reaches of some gravel bed rivers (Fiumare) in Calabria region. Finally, the theoretically-based relationship for estimating the Gamma function is calibrated by the overall available database (205 reaches). In this way the three coefficients of the theoretically based Gamma function are estimated for a wide range of slopes (0.1%-6.19%) and hydraulic conditions (Froude number values ranging from 0.08 to 1.25).In conclusion, the analysis shows that the Darcy-Weisbach friction factor for gravel bed rivers can be accurately estimated by the approach based on a power-velocity profile and the theoretically-based relationship proposed for estimating Gamma function. The analysis also points out a performance in estimating mean flow velocity better than that obtained in a previous study carried out by the authors.
Lingua originaleEnglish
pagine (da-a)220-227
Numero di pagine8
RivistaJournal of Agricultural Engineering
Volume49
Stato di pubblicazionePublished - 2018

All Science Journal Classification (ASJC) codes

  • Bioengineering
  • Industrial and Manufacturing Engineering
  • Mechanical Engineering

Cita questo

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title = "Assessing theoretical flow velocity profile and resistance in gravel bed rivers by field measurements",
abstract = "Previous studies showed that integrating a power velocity profile, deduced applying dimensional analysis and the incomplete self-similarity condition, the flow resistance equation for open channel flow can be obtained. At first, in this paper the relationship between the Gamma function of the power velocity profile, the channel slope and the Froude number, which was already empirically introduced in a previous paper, is now theoretically deduced. Then this relationship is calibrated using the field measurements of flow velocity, water depth and bed slope carried out in 101 reaches of gravel bed rivers available by literature. The proposed relationship for estimating Gamma function and the theoretical flow resistance equation are also tested by an independent dataset of 104 reaches of some gravel bed rivers (Fiumare) in Calabria region. Finally, the theoretically-based relationship for estimating the Gamma function is calibrated by the overall available database (205 reaches). In this way the three coefficients of the theoretically based Gamma function are estimated for a wide range of slopes (0.1{\%}-6.19{\%}) and hydraulic conditions (Froude number values ranging from 0.08 to 1.25).In conclusion, the analysis shows that the Darcy-Weisbach friction factor for gravel bed rivers can be accurately estimated by the approach based on a power-velocity profile and the theoretically-based relationship proposed for estimating Gamma function. The analysis also points out a performance in estimating mean flow velocity better than that obtained in a previous study carried out by the authors.",
author = "{Porto, P.} and Vito Ferro",
year = "2018",
language = "English",
volume = "49",
pages = "220--227",
journal = "Journal of Agricultural Engineering",
issn = "1974-7071",
publisher = "PagePress",

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TY - JOUR

T1 - Assessing theoretical flow velocity profile and resistance in gravel bed rivers by field measurements

AU - Porto, P.

AU - Ferro, Vito

PY - 2018

Y1 - 2018

N2 - Previous studies showed that integrating a power velocity profile, deduced applying dimensional analysis and the incomplete self-similarity condition, the flow resistance equation for open channel flow can be obtained. At first, in this paper the relationship between the Gamma function of the power velocity profile, the channel slope and the Froude number, which was already empirically introduced in a previous paper, is now theoretically deduced. Then this relationship is calibrated using the field measurements of flow velocity, water depth and bed slope carried out in 101 reaches of gravel bed rivers available by literature. The proposed relationship for estimating Gamma function and the theoretical flow resistance equation are also tested by an independent dataset of 104 reaches of some gravel bed rivers (Fiumare) in Calabria region. Finally, the theoretically-based relationship for estimating the Gamma function is calibrated by the overall available database (205 reaches). In this way the three coefficients of the theoretically based Gamma function are estimated for a wide range of slopes (0.1%-6.19%) and hydraulic conditions (Froude number values ranging from 0.08 to 1.25).In conclusion, the analysis shows that the Darcy-Weisbach friction factor for gravel bed rivers can be accurately estimated by the approach based on a power-velocity profile and the theoretically-based relationship proposed for estimating Gamma function. The analysis also points out a performance in estimating mean flow velocity better than that obtained in a previous study carried out by the authors.

AB - Previous studies showed that integrating a power velocity profile, deduced applying dimensional analysis and the incomplete self-similarity condition, the flow resistance equation for open channel flow can be obtained. At first, in this paper the relationship between the Gamma function of the power velocity profile, the channel slope and the Froude number, which was already empirically introduced in a previous paper, is now theoretically deduced. Then this relationship is calibrated using the field measurements of flow velocity, water depth and bed slope carried out in 101 reaches of gravel bed rivers available by literature. The proposed relationship for estimating Gamma function and the theoretical flow resistance equation are also tested by an independent dataset of 104 reaches of some gravel bed rivers (Fiumare) in Calabria region. Finally, the theoretically-based relationship for estimating the Gamma function is calibrated by the overall available database (205 reaches). In this way the three coefficients of the theoretically based Gamma function are estimated for a wide range of slopes (0.1%-6.19%) and hydraulic conditions (Froude number values ranging from 0.08 to 1.25).In conclusion, the analysis shows that the Darcy-Weisbach friction factor for gravel bed rivers can be accurately estimated by the approach based on a power-velocity profile and the theoretically-based relationship proposed for estimating Gamma function. The analysis also points out a performance in estimating mean flow velocity better than that obtained in a previous study carried out by the authors.

UR - http://hdl.handle.net/10447/338336

UR - https://www.agroengineering.org/index.php/jae/article/view/810

M3 - Article

VL - 49

SP - 220

EP - 227

JO - Journal of Agricultural Engineering

JF - Journal of Agricultural Engineering

SN - 1974-7071

ER -