Bagnold Number

Written by Jerry Ratzlaff on . Posted in Dimensionless Numbers

Bagnold number, abbreviated as \(V_d\), a dimensionless number, is the ratio of grain collision stresses to various fluid stresses in a granular flow with interstitial Newtonian fluid.

Bagnold Number Formula

\(\large{ Ba = \frac{ \rho \; d^2 \; \lambda^{\frac{1}{2}} \; \dot {\gamma} }{ \mu }  }\)

Where:

\(\large{ Ba }\) = Bagnold number

\(\large{ d }\) = grain diameter

\(\large{ \lambda }\)  (Greek symbol lambda) = linear concentration

\(\large{ \rho }\)   (Greek symbol rho) = particle density

\(\large{ \dot {\gamma} }\)   (Greek symbol gamma) = shear rate

\(\large{ \mu }\)  (Greek symbol mu) = dynamic viscosity