Field investigation on friction factor in mountainous cobble-bed and boulder-bed rivers  

作　　者：Hossein AFZALIMEHR Jacques GALLICHAND Jueyi SUI Ehsan BAGHER 

机构地区：[1]Assoc., Prof., Department of Water Engineering Isfahan University of Technology, lsfahan, Iran [2]Prof., Departement des sols et de g6nieagroalimentaire Universite Laval, St-Foy,QC, canada [3]Assoc., Prof. Environmental EngineeringProgram, University of Northern British Columbia, Prince George, BC, Canada, V2N 4V9 [4]Graduate student, Water Engineering Department, lsfahan University of Technology

出　　处：《International Journal of Sediment Research》2011年第2期210-221,共12页国际泥沙研究（英文版）

摘　　要：This paper presents results of the friction factor of cobble-bed and boulder-bed rivers based on 23 field measurements in three mountainous rivers in Iran. Results reveal that features of our measured velocity profiles in boulder-bed rivers in mountainous region do not present a specific shape but illustrate specific pattern in cobble-bed rivers. This difference is attributed to scale effect of relative submergence. It is found that the relative submergence in cobble and boulders-bed rivers is the only key parameter that influences friction factor estimation and other parameters such as particle Froude number and Froude number have few impacts on flow resistance of cobble-bed and boulder-bed rivers. The proposed relationship for estimation for the friction factor should be useful for large coarse-bed rivers.This paper presents results of the friction factor of cobble-bed and boulder-bed rivers based on 23 field measurements in three mountainous rivers in Iran. Results reveal that features of our measured velocity profiles in boulder-bed rivers in mountainous region do not present a specific shape but illustrate specific pattern in cobble-bed rivers. This difference is attributed to scale effect of relative submergence. It is found that the relative submergence in cobble and boulders-bed rivers is the only key parameter that influences friction factor estimation and other parameters such as particle Froude number and Froude number have few impacts on flow resistance of cobble-bed and boulder-bed rivers. The proposed relationship for estimation for the friction factor should be useful for large coarse-bed rivers.

关 键 词：Boulder-bed Cobble-bed Friction factor Mountainous river Relative submergence 

分 类 号：TV133[水利工程—水力学及河流动力学]