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This program uses the Stokes
equation to calculate the sedimentation (settling) speed of
spherical particles
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The Stokes equation permits the
calculation of the drag forces of a spherical particle in a
viscous liquid at very low Reynolds numbers. Stoke's equation
is derived from the generally not solvable Navier-Stokes
equation.
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Vt is
the settling or terminal speed of the particle, g is the
acceleration of the spherical particle, d
is the diameter of the particle, pp
is the density of the particle, pm
the density of the liquid medium, µ
is the dynamic viscosity of the medium. The diameter of the
particle is the Stoke's diameter, which is not the actual
diameter of the particle, but rather the diameter effected by
absorption, hydration and deviation from the spherical shape.
For non-spherical particle the Stoke's diameter can be smaller
than the actual diameter. Absorption of polymers on a particle
will increase the Stoke's diameter.
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Input
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Select
Units
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Enter data
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Conversion
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Units
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Acceleration of gravity (g)
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m/s2
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Particle diameter (d)
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m
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Density of particle (pp)
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g/m3
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Density of medium (pm)
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g/m3
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Viscosity of medium (µ)
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g.m-1.s-1
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Results
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Settling Speed (Vt
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Acheson,
D. J. (1990), Elementary Fluid Dynamics,
Oxford Applied Mathematics and Computing Science Series, Oxford
University Press, ISBN
0198596790
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