Sediment-Laden Flow in Open-Channels under Noncapacity and Capacity Conditions

TLDR: In this paper, the Rouse number is used to determine the suspended load component of sediment transport in open-channel flow, and the vertical distribution of the concentration of suspended particles is of importance.

Abstract: To determine the suspended load component of sediment transport in open-channel flow, the vertical distribution of the concentration of suspended particles is of importance. It is usual to determine this distribution by solving the diffusion-convection equation under appropriate boundary conditions. The exponent in the resulting equation is the Rouse number, defined as z′ = vss/βκ¯u*. The β¯-value has been the subject of much research. In natural alluvial channels the sediment-laden flow is usually in capacity (saturation) condition, implying that the flow will charge (saturate) itself with particles available in the bed load and/or on the bed itself. However, simulation of sediment-laden flow in a laboratory flume is achieved typically by externally adding particles to the flow. Consequently, it is not certain that the flow was in capacity condition. The resulting β¯-values are often values for noncapacity conditions. They should not be used for natural alluvial channels, because they are misleading. Rep...