Bed load effect on flow resistance in meandering open channel flows

Abstract

River flow resistance i.e., friction factors have significant influence on river’s conveyance capacity and sediment transport. Darcy’s friction factor f is an important factor which helps to predict the stage discharge relationship in open channel. Flow resistance in rivers and open channels is of enormous importance in river engineering and dynamics. Accurate estimation of river flow resistance is of importance to predict the stage-discharge relationship in rivers, thus to evaluate the likelihood of river flooding and issue warning of flooding. In this research work, the meander path considered is from one bend apex to the next bend apex which changes its course at the cross-over. Bend apex is the position of maximum curvature and cross-over represents the section at which the sinuous channel changes its sign. In this research work, variation of velocity profile along the width and depth of the channel has been methodically analyzed at different cross-sections along a meander path of a sinuous channel of 60° cross-over angle. Longitudinal velocity distributions along the width and depth of the channel, i.e., the horizontal and vertical velocity profiles are analyzed. The present research work is intended to examine the various flow characteristics of a meandering channel with bed load. Study done on the variation of flow resistance in terms of the Darcy-Weisbach friction factor in meandering open channel flows under bed load condition over different discharges, different flow depths. Analysis done on interdependency of various factors such as Reynolds number (Re), Roughness Reynolds number (Re* ), Froude’s number (Fr), ratio of flow depth to width of main channel y/b, Relative Submergence (R/D) with respect to the friction factor in a meandering channel under bed load condition