Quantitative dimensionless measure f of the friction forces between fluid pipe flow and inner pipe walls based on Darcy–Weisbach equation.
It depends on Reynolds number \rm Re and roughness \epsilon (see Fig. 1): f =f({\rm Re}, \, \epsilon).
Fig. 1. Schematic chart showing how Darcy friction factor depends on Reynolds number \rm Re and roughness \epsilon (following [1]) |
In engineering practice one can use either Moody Chart or Darcy friction factor @model to estimate the actual value of Darcy friction factor .
See also
Physics / Fluid Dynamics / Pipe Flow Dynamics / Darcy–Weisbach equation
[ Darcy friction factor @model ] [ Moody Chart ]
Reference
[1] https://gmallya.com/moodys-friction-factor-calculator/