EW/FS/FF/FF4.2.2.
Steady and uniform turbulent flow in pipes
Friction loss in a pipeline
The head loss due to friction according to the Darcy-Weisbach equation is:
The Colebrook-White formula is generally applicable and probably the
most widely used. The implicit equation for pipes (full flow) is shown
below:
This implicit equation can be solved by an iteration process on a
computer.
A number of explicit approximation were provided to determine the
friction factor of which the following by Barr (1972) is an example.
A graphical presentation, provided by Moody (1944) is a ‘handy tool’ for
estimating head losses without the aid of a computer. This is generally
referred to as the Moody diagram and is illustrated in Fact sheet4.2.3.
Barr, D. New forms of equations for the correlation of pipe resistance data. Proc. ICE,
1972.
Moody, L. Friction factors for pipe flow. Transaction, Am,Soc.Mec.Eng. No.66, 1944.
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