# Fanning Friction Factor

Not Reviewed
Equation / Last modified by EmilyB on 2016/07/11 17:53
f =
Fanning Friction Factor
Variable Instructions Datatype
(tau)"local shear stress" Enter local shear stress Decimal (N/cm²)
(rho)"density of the fluid" Enter density of the fluid Decimal (kg/m³)
(u)"local flow velocity" Enter local flow velocity Decimal (m/s)
Type
Equation
Category
vCommons
Contents
3 variables
Rating
ID
EmilyB.Fanning Friction Factor
UUID
b2f729e4-478e-11e6-9770-bc764e2038f2

The Fanning Friction Factor is a dimensionless number used as a local parameter in continuum mechanics calculations. It is defined as the ratio between the local sheer stress and the local flow kinetic energy density: f=tau/(rhou^2/2), where:

• tau = local sheer stress
• rho = density of the fluid
• u = local flow velocity

## References

The formula and definition are from Wikipedia (https://en.wikipedia.org/wiki/Fanning_friction_factor).