Swamee and Jain Equation
Note: The Kinematic Viscosity is used in determining the friction coefficient in the Darcy-Weisbach Friction Method. The default units are initially set by Bentley Systems.
| f | = | Friction factor (unitless) | |
| ε | = | Roughness height (m, ft.) | |
| D | = | Pipe diameter (m, ft.) | |
| Re | = | Reynolds number (unitless) |
The friction factor is dependent on the Reynolds number of the flow, which is dependent on the flow velocity, which is dependent on the discharge. As you can see, this process requires the iterative selection of a friction factor until the calculated discharge agrees with the chosen friction factor.