Archimedes Number

Written by Jerry Ratzlaff. Posted in Dimensionless Numbers

Archimedes number is a dimensionless number that analyzes flow as it relates to a system of density differences.  It is used when dealing with Gravitational settling of particles in fluid.


\(Ar = \frac { g    l^3   \rho_f \left( \rho_b \;-\; \rho _f \right)}    {\mu^2} \)


\(Ar\) = Archimedes number

\(g\) = gravitational acceleration 

\(\rho_f\) = fluid density

\(\rho_b\) = density of the body flowing through the fluid

\(\mu\) = dynamic viscosity of the fluid

\(l\) = length