Formulas for friction factor in transitional regimes

• Main Author: Cheng, Nian-Sheng
• Other Authors: School of Civil and Environmental Engineering
• Format: Article
• Language: English
• Published: 2012
• Subjects: DRNTU::Engineering::Civil engineering
• Online Access: https://hdl.handle.net/10356/93959; http://hdl.handle.net/10220/7647
• Institution: Nanyang Technological University

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.