University of Illinois at Urbana-Champaign. Water Resources Center
Abstract
An analytical study was conducted for the determination of the Weisbach resistance coefficient for flow in sand-bed straight channels. Available experimental data were reanalyzed based on dimensional analysis and fluid mechanics concepts. It was found that for flows having width to depth ratio greater than 5, there is a unique and systematic relationship among the Weisbach resistance coefficient f, the Froude number of the flow, and the sediment particle size to hydraulic radius ratio. The bed form which also is a dependent variable is also uniquely determined. For flow with Froude number less than 0.5 where its effect can be neglected, the resistance coefficient can be expressed as a function of the Reynolds number, sediment size to hydraulic radius ratio, and the sediment terminal fall velocity to shear velocity ratio. Application of the results for engineering purposes is also discussed. The technique for engineering applications of the results appear to be quite simple.U.S. Department of the InteriorU.S. Geological SurveyOpe
