Formulas for friction factor in transitional regimes
Date of Issue2008
School of Civil and Environmental Engineering
This note concerns variations of the friction factor in the two transitional regimes, one between laminar and turbulent flows and the other between fully smooth and fully rough turbulent flows. An interpolation approach is developed to derive a single explicit formula for computing the friction factor in all flow regimes. The results obtained for pipe flows give a better representation of Nikuradse's experimental data, in comparison with other implicit formulas available in the literature. Certain modifications are also made for applying the obtained friction formula to open-channel flows.
Journal of hydraulic engineering
© 2008 ASCE. This is the author created version of a work that has been peer reviewed and accepted for publication byJournal of Hydraulic Engineering, Amemrican Society of Civil Engineers. It incorporates referee’s comments but changes resulting from the publishing process, such as copyediting, structural formatting, may not be reflected in this document. The published version is available at: [DOI: http://dx.doi.org/10.1061/(ASCE)0733-9429(2008)134:9(1357)]