Darcy Friction Factor
Darcy friction factor, abbreviated as \(f_d\), a dimensionless number, also called Darcy-Weisbach friction factor, formulas are equations that help calculate the friction losses in pipe flow and open channel flow. This coefficient is used in the Darcy-Weisbach equation.
Fanning friction factor is not the same as the Darcy friction factor. It is equal to 1/4 the Darcy friction factor. Since they are basically the same, you need to note which one is being used when doing calculations. Use \(f_f\) or \(f_d\) for the Fanning or Darcy friction factor, respectively.
Darcy friction factor formula |
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| \(\large{ f_d = \frac { 2 \; h_l \; d \; g } { l_p \; v^2 } }\) | ||
| Symbol | English | Metric |
| \(\large{ f_d }\) = Darcy friction factor | \(\large{ dimensionless }\) | |
| \(\large{ g }\) = gravitational acceleration | \(\large{ \frac{ft}{sec^2} }\) | \(\large{ \frac{m}{s^2} }\) |
| \(\large{ h_l }\) = head loss | \(\large{ ft }\) | \(\large{ m }\) |
| \(\large{ l_p }\) = lenght of pipe | \(\large{ ft }\) | \(\large{ m }\) |
| \(\large{ v }\) = mean flow velocity | \(\large{ \frac{ft}{sec} }\) | \(\large{ \frac{m}{s} }\) |
| \(\large{ d }\) = pipe inside diameter | \(\large{ in }\) | \(\large{ mm }\) |
Article Links
- Darcy Friction Factor - Brkic - Determination of the Darcy friction factor using the Brkic method.
- Darcy Friction Factor - Free Surface Flow - Darcy friction factor for pipe flow and open channel flow.
- Darcy Friction Factor - Laminar Flow - Darcy friction factor for laminar flow.
