# Swamee-Jain Equation

The Swamee-Jain Equation can be used to solve the Darcy-Weisbach friction factor for a full-flowing pipe and is accurate to 1.0% of the Colebrook-White Equation for \(\large{ 10^{-6} < \frac{\epsilon}{d} < 10^{-2} }\) and \(\large{ 5,000 < Re < 10^8 }\).

## swamee-jain equation formulas |
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\(\large{ f = \frac{0.25}{[log \; (\frac{\epsilon}{3.7\;d} + \frac{5.74}{Re^{0.9}})]^2} }\) \(\large{ f = \frac{0.25}{log_{10} \; (\frac{ \frac{\epsilon}{ d } }{3.7} + \frac{5.74}{Re^{0.9}})^2} }\) |
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Symbol |
English |
Metric |

\(\large{ f }\) = friction factor | \(\large{ dimensionless }\) | |

\(\large{ \epsilon }\) (Greek symbol epsilon) = absolute roughness | \(\large{ in }\) | \(\large{ mm }\) |

\(\large{ d }\) = inside diameter of pipe | \(\large{ in }\) | \(\large{ mm }\) |

\(\large{ Re }\) = Reynolds number | \(\large{ dimensionless }\) |