Stokes-Einstein Equation

Written by Jerry Ratzlaff on . Posted in Fluid Dynamics

Stokes-Einstein equation, abbreviated as SE, is used for evaluating diffusion of spherical particles through a liquid with low Reynolds numbers.

 

Stokes-Einstein Equation

\(\large{ D =  \frac{ k_b \; T }{ 6 \; \pi \; \mu \; r }   }\)   

Where:

 Units English Metric
\(\large{ D }\) = diffusion coefficient \(\large{lbf}\) \(\large{N}\)
\(\large{ k_b }\) = Boltzmann constant \(\large{\frac{lbm-ft^2}{sec^2}}\) \(\large{\frac{kJ}{molecule-K}}\)
\(\large{ \mu }\) (Greek symbol mu) = dynamic viscosity \(\large{\frac{lbf-sec}{ft^2}}\) \(\large{Pa-s}\)
\(\large{ \pi } \) = Pi \(\large{3.141 592 653 ...}\)
\(\large{ r }\) = radius of spherical parcticle \(\large{in}\) \(\large{mm}\)
\(\large{ T }\) = temperature \(\large{F}\) \(\large{K}\)

 

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Tags: Coefficient Equations Soil Equations Diffusion Equations