Hazen-Williams Flow through an Open Channel Equation

Hazen-Williams method is only valid for water flowing at ambient temperatures, the Darcy-Weisbach method should be used for other liquids or gases.  The Hazen-Williams Equation can be used for flow through an open channel or through a pressurized pipe.

 

Hazen-Williams flow through an open channel Equation
\( v \;=\; k \;C \; r_h^{0.63}\; m^{0.54}  \)
Symbol	English	Metric
\( v \) = Mean Flow Velocity	\(ft\;/\;sec\)	\(m\;/\;s\)
\( k \) = Conversion Factor	\(dimensionless \)	\(dimensionless \)
\( C \) = Hazen-Williams Coefficient	\( dimensionless \)	\(dimensionless \)
\( m \) = Hydraulic Grade line Slope	\( ft \)	\(m \)
\( r_h \) = Hydraulic Radius	\( ft \)	\( m \)