RELATIVE CELERITIES OF MOBILE BED FLOWS WITH FINITE SOLIDS CONCENTRATIONS

The relative magnitudes of the celerities at which disturbances on the water surface and the bed are propagated play a key role in the mathe matical modeling of mobile bed flow. Earlier analyses assumed that the solids concentration of the how was negligible. This assumption is in appropriate both for some natural streams and for many aqueous mine-wa ste disposal applications. Here, the relative celerities of mobile bed flow are determined for flows with finite solids concentrations. The solids concentration is assumed to be a function of the velocity and d epth of dow The analysis confirms and extends the results of earlier a nalyses. It is shown that the movement of the sediment and the water c an be considered to be mathematically independent of each other only w ithin very limited ranges of solids concentration and Froude number. T his severely constrains the application of numerous existing mathemati cal models to mobile bed hows with relatively high solids concentratio ns.