United friction resistance in open channel flows  

作　　者：李硕林 史浩然 薛万云 槐文信 

机构地区：[1]State Key Laboratory of Water Resources and Hydropower Engineering Science, Wuhan University

出　　处：《Journal of Hydrodynamics》2015年第3期469-472,共4页水动力学研究与进展B辑（英文版）

基　　金：supported by the National Natural Science Foun-dation of China(Grant Nos.51479007,11172218 and 11372232);the Specialized Research Fund for the Doctoral Program of Higher Education(Grant No.20130141110016)

摘　　要：It is now over half a century since Keulegan conducted his open channel flow experiments. Over the past decades, many empirical formulae were proposed based on his results, however, there is still not a combined expression to describe the effects of friction over all hydraulic regions in open channel flows. Therefore, in this letter, based on the analysis of the implicit model and the logarithmic matching method, the results of Keulegan （for authentic experiment data are no longer available, here we adopt the analytical solutions given by Dou） are rescaled into one monotone curve by combining the Reynolds number and the relative roughness of the river bed. A united expression that could cover the entire turbulence regions and be validated with Dou＇s analytical solutions is suggested to estimate the friction factor throughout the turbulent region in open channel flows, with higher accuracy than that of the previous formulas.It is now over half a century since Keulegan conducted his open channel flow experiments. Over the past decades, many empirical formulae were proposed based on his results, however, there is still not a combined expression to describe the effects of friction over all hydraulic regions in open channel flows. Therefore, in this letter, based on the analysis of the implicit model and the logarithmic matching method, the results of Keulegan （for authentic experiment data are no longer available, here we adopt the analytical solutions given by Dou） are rescaled into one monotone curve by combining the Reynolds number and the relative roughness of the river bed. A united expression that could cover the entire turbulence regions and be validated with Dou＇s analytical solutions is suggested to estimate the friction factor throughout the turbulent region in open channel flows, with higher accuracy than that of the previous formulas.

关 键 词：open channel flows frication factor united formula implicit model logarithmic matching method 

分 类 号：O35[理学—流体力学]