Author(s): K. G. Ranga Raju

Linked Author(s): K.G. Ranga Raju

Keywords: No Keywords

Abstract: The transport of sediment mixtures in open channelsis complicated on account of the fact that thecondition for initiation of motion of a given sizeof sediment as well as its transport rate are affectedby the presence of the other sizes in the mixture.The finer fractions moving as bed load are shelteredby the coarser fractions,and the coarser particles,in turn,are exposed more to the action of flowpast them.As such,the actual force experiencedby a certain fraction of sediment mixture at agiven average shear stress is different from whatit would be at the same shear stress if the materialwere uniform.Further this difference in forcesis a function of the bed composition,and the fluidand flow characteristics.In general,the size distribu-tion of the transported material is dependent onthe shear stress and is different from that of thebed material.Hence the sediment load calculatedby making use of any of the methods based on asingle representative size results in large errorin such cases.It is thus necessary to know the trans-port rates of individualfractions of the bed material,if the bed load and suspended load transport ratesand their composition are to be predicted accurately.

DOI:

Year: 1985