EFFECTS OF HIGH SEDIMENT CONCENTRATIONS ON VELOCITY AND SEDIMENT DISTRIBUTIONS.

Several classifications are required to describe sediment-transporting flow. The flow may be turbulent or laminar, Newtonian or non-Newtonian, and may also have a uniform or nonuniform concentration profile. As sediment concentration or transport increases, the character of flow changes. Generally, fall velocity and effective fall diameter decrease. The viscosity of the mixture increases. The flow becomes non-Newtonian when particle interaction becomes dominant. In the lowest concentration ranges, flows are Newtonian, generally nonuniform by concentration, and almost exclusively turbulent. Mudflows are non-Newtonian and usually laminar flows of a nearly uniform concentration. In the interim ranges are found transitions to non-Newtonian and laminar flows and uniform concentration profiles.