Dimensionless quantity characterising the ratio of inertial forces to viscous forces and corresponding fluid flow regime:
{\rm Re} = \frac{u \, d}{\nu} = \frac{\rho \, u \, d}{\mu} |
where
| average cross-sectional flow velocity | |
| characteristic linear dimension of the fluid conduit | |
| fluid density | |
| dynamic viscosity | |
| kinematic viscosity |
The physical meaning of Reynolds number is the ratio of Inertial forces to Viscous forces:
{\rm Re} = \frac{{\rm Inertial} \ {\rm forces}}{{\rm Viscous} \ {\rm forces}} = \frac{u \, d}{\nu} |
See also
Physics / Fluid Dynamics / Fluid flow regimes
[ Reynolds number in Pipe Flow]