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Rill flow resistance law under equilibrium bed‐load transport conditions
Author(s) -
Di Stefano Costanza,
Nicosia Alessio,
Pampalone Vincenzo,
Palmeri Vincenzo,
Ferro Vito
Publication year - 2019
Publication title -
hydrological processes
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.222
H-Index - 161
eISSN - 1099-1085
pISSN - 0885-6087
DOI - 10.1002/hyp.13402
Subject(s) - froude number , rill , flow (mathematics) , mechanics , open channel flow , sediment transport , geology , mathematics , geotechnical engineering , sediment , physics , geomorphology
In this paper, a recently deduced flow resistance equation for open channel flow was tested under equilibrium bed‐load transport conditions in a rill. First, the flow resistance equation was deduced applying dimensional analysis and the incomplete self‐similarity condition for the flow velocity distribution. Then, the following steps were carried out for developing the analysis: (a) a relationship (Equation [Disp. Item 13. Γv=0.5092F0.9710s0.4747. ...]) between the Γ function of the velocity profile, the rill slope, and the Froude number was calibrated by the available measurements by Jiang et al.; (b) a relationship (Equation [Disp. Item 17. Γv=0.4249F1.1097s0.4749θ0.1377, ...]) between the Γ function, the rill slope, the Shields number, and the Froude number was calibrated by the same measurements; and (c) the Darcy–Weisbach friction factor values measured by Jiang et al. were compared with those calculated by the rill flow resistance equation with Γ estimated by Equations [Disp. Item 13. Γv=0.5092F0.9710s0.4747. ...] and [Disp. Item 17. Γv=0.4249F1.1097s0.4749θ0.1377, ...]. This last comparison demonstrated that the rill flow resistance equation, in which slope and Shields number, representative of sediment transport effects, are introduced, is characterized by the lowest values of the estimate errors.