Flow resistance of gravel bed channels

• Published in: International journal of sediment research Vol. 29; no. 1; pp. 126 - 132
• Main Authors: WANG, Wen C., DAWDY, David R.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.03.2014; Multech Engineering Consultants, Inc. 1650 Zanker Road, Suite 210, San Jose, CA 95112
• Subjects: Darcy-Weisbach friction factor; Flow resistance; Gravel bed channels; Open channels; Relative roughness; Relative submergence; 弗劳德数; 摩擦系数; 水力半径; 相对粗糙度; 碎石; 系数估计; 道床阻力; 阻力公式; Flow resistance; Gravel bed channels; Open channels; Relative submergence; Relative roughness; Darcy-Weisbach friction factor
• ISSN: 1001-6279
• DOI: 10.1016/S1001-6279(14)60028-7

Existing resistance formulas produce a wide range of friction-factor estimates for gravel bed streams. The purpose of this paper is to develop a reliable resistance formula in terms of the Darcy-Weisbach friction factor f Published data were screened and used to establish the formula. The existing formulas have considered thatfis a function of relative roughness D84/R only, where R is the hydraulic radius and 1984 is the particle size referred to the intermediate diameter that equals or exceeds that of 84 percent of bed sediments. In this paper, f is considered as a ftmction of Froude number in addition to the relative roughness, ffor D84/R〉l displays a different trend than that for Dsn/R〈l perhaps due to the invalid assumption of a logarithmic velocity distribution for D84/R〉l. Anfformula for Dsa/R〈l has been established.