Churchill correlation (friction factor)
1.
Introduction
2. Churchill equation
3. Excel calculation tool
1. Introduction
The friction factor is used to calculate the pressure drop due to the
flow of a fluid in a pipe. It represents the interaction in between
the fluid and the pipe.
There are different ways to calculate it,
one can be graphical, using a Moody graph, but for automating
calculation it is not practical, thus correlations are required. The
Colebrook correlation is usually
admitted as being accurate enough for most industrial applications
but presents a difficulty as it does not explicitly express the
friction factor, that is why it may be interesting to consider
Churchill equation that allows to directly calculate the friction
factor.
Note that the friction factor used here is
Darcy (also called Darcy-Wesibach or Moody) friction factor.
With :
f = Darcy friction factor
D = Pipe diameter (m)
Re =
Reynolds number
ε = pipe roughness (m)
3. Excel calculation tool
Please access to this
page to download the free xls calculation tool for Churchill
correlation.