# Hazen-Williams Flow through an Open Channel Equation

Written by Jerry Ratzlaff 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

 $$\large{ v = k \;C \; r_h^{0.63}\; m^{0.54} }$$

### Where:

$$\large{ v }$$ = mean flow velocity

$$\large{ k }$$ = conversion factor

$$\large{ C }$$ = Hazen-Williams coefficient

$$\large{ m }$$ = hydraulic grade line slope

$$\large{ r_h }$$ = hydraulic radius