Swamee-Jain Equation

Swamee-Jain equation, also called Jain equation or the Darcy-Weisbach equation, is used in fluid mechanics to calculate the pressure drop or head loss of a fluid flowing through a pipe.  It's an empirical equation derived from experimental data and is widely used in engineering and fluid dynamics for estimating pressure losses due to friction in pipes.

 

swamee-jain equation formula
\( f = 0.25 \;/\; [\; log \; [\; (\epsilon \;/\; 3.7\;d)  + ( 5.74 \;/\; Re^{0.9})\; ] \; ]^2  \)
Symbol	English	Metric
\( f \) = Friction Factor	\( dimensionless \)	\( dimensionless \)
\( \epsilon \)  (Greek symbol epsilon) = Absolute Roughness	\( in \)	\( mm \)
\( d \) = Inside Diameter of Pipe	\( in \)	\( mm \)
\( Re \) = Reynolds Number	\( dimensionless \)	\( dimensionless \)