Colebrook-White Equation

Written by Jerry Ratzlaff on . Posted in Fluid Dynamics

Colebrook-White equation, also called Colebrook equation, is used toiteratively solve the Darcy-Weisback friction factor. This equation uses US units. To convert between US and SI units, use our calculator.

 

Colebrook-White Equation formula

\(\large{ \frac{1}{\sqrt{f}} = -2 \; log_{10} \left( \frac{ \epsilon\ }{ 3.7 \; d_h } + \frac{ 2.51 }{ Re \; \sqrt{ f } } \right) }\) 

Where:

 Units English Metric
\(\large{ \epsilon }\) (Greek symbol epsilon) = absolute roughness \(\large{ in }\) \(\large{ mm }\)
\(\large{ f }\) = friction factor \(\large{ dimensionless }\)
\(\large{ d_h }\) = hydraulic diameter \(\large{ in }\) \(\large{ mm }\)
\(\large{ Re }\) = Reynolds number \(\large{ dimensionless }\)

 

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Tags: Flow Equations