STUDIES ON MUD FLOW -Stress Structure

The flow characteristics of fine sands and water mixture is discussed in terms of experimented results concerning the flow resistance, sediment concentration profiles and sediment diffusion. (1) Flow resistance does not change so much in the range of sediment concentration less than 10 percent by volume, but increases gradually and then rapidly with increase of the sediment fraction. (2) The profiles of sediment concentration can be evaluated well by Rouse's formula in the low range of sediment fraction. These tend to be uniform when the sediment fraction increases. (3) Turbulent diffusion coefficients of tracer particles decrease almost linearly with increase of sediment fraction.These facts indicate that some stresses except Reynolds ones dominate above the range of general open channel flows with suspended loads.