Hooman Fatoorehchi
Assistant Professor
School of Chemical Engineering
University of Tehran, Tehran, Iran
Formulas in this page are typed in $\LaTeX$.

Fluid Mechanics I

The Moody diagram that gives the Darcy-Weisbach friction factor.


You can download a high-quality PDF file version of this diagram by clicking HERE.

The Darcy-Weisbach friction factor for single-phase turbulent flow in rough pipes:

$\frac{1}{\sqrt{f}}=-2 \log_{10}\left( \frac{150.39}{Re^{0.98865}}-\frac{152.66}{Re}+\frac{\epsilon}{3.71 D} \right) $

Reference: DOI= 10.1016/j.nucengdes.2011.07.042

Remark: In the advanced Bernoulli equation (the one from Bird's textbook), the friction factor is Fanning's friction factor.

The Darcy or the Darcy-Weisbach Friction Factor

$f=4\frac{\tau_w}{\frac{\rho V^2}{2}}=8\frac{\tau_w}{\rho V^2} $,
where $\tau_w$ is the shear stress value at the inner wall (of the pipe).


*** Go to the online Pipeline Pressure Drop Calculator


Minor (non-frictional) Losses:

Types of Elbows
(Reference: Lecture Notes by S. Leon, Florida International University)



Flow through a Globe Valve
(Reference: Munson's textbook)



Compressor Type Selection Chart
(Reference: W. Dimoplon, "What Process Engineers Need to Know about Compressors")




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