NA-05 - Cleaning: Solids in Drain and Sewer Systems (Demo)

Transport behaviour of solids

Transition from bed load to sediment load transport

With increasing turbulence and flow velocity, particles (solids) of varying size and density can be brought into suspension, with a decrease in velocity the particles settle to the bottom of the channel. This approximate relationship can be shown through the FROUDE number of particles equation:



v = flow velocity [m/s]
d = particle diameter [m]
g = gravitational acceleration [m/s2]
 

Research by [Kress1964] has shown that a particle floats when Fr* > 19 and sinks when Fr* < 19, resulting in the limiting grain diameter equation:



vm = average flow velocity
dgr = limiting particle diameter
g = gravitational acceleration

 

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