Hazen-Williams Flow through an Open Channel Equation

on . Posted in Fluid Dynamics

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 formula

$$\large{ v = k \;C \; r_h^{0.63}\; m^{0.54} }$$
Symbol English Metric
$$\large{ v }$$ = mean flow velocity $$\large{\frac{ft}{sec}}$$ $$\large{\frac{m}{s}}$$
$$\large{ k }$$ = conversion factor   $$\large{ dimensionless }$$
$$\large{ C }$$ = Hazen-Williams coefficient   $$\large{ dimensionless }$$
$$\large{ m }$$ = hydraulic grade line slope $$\large{ ft }$$ $$\large{ m }$$
$$\large{ r_h }$$ = hydraulic radius $$\large{ ft }$$ $$\large{ m }$$