# Bagnold Number

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

## Formulas that use Bagnold Number

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

### Where:

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

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

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

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

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

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