Darcy friction factor - Swamee–Jain equation
In fluid dynamics, the Darcy friction factor formulae are equations that allow the calculation of the Darcy friction factor, a dimensionless quantity used in the Darcy–Weisbach equation, for the description of friction losses in pipe flow as well as open-channel flow.
The Darcy friction factor is also known as the Darcy–Weisbach friction factor, resistance coefficient or simply friction factor; by definition it is four times larger than the Fanning friction factor.
The Swamee–Jain equation is used to solve directly for the Darcy–Weisbach friction factor f for a full-flowing circular pipe. It is an approximation of the implicit Colebrook–White equation.Related formulas
|f||Darcy friction factor (dimensionless)|
|ϵ||Pipe's effective roughness height (m)|
|D||Pipe's inside diameter (m)|
|Re||Reynolds number (dimensionless)|