# Hydraulic Radius of a Rectangular Channel

Written by Jerry Ratzlaff on . Posted in Fluid Dynamics

Hydraulic radius, abbreviated as $$r_h$$, is the cross section area of water in a pipe or channel divided by the wetting perimeter.

### Hydraulic Radius of a Rectangular Channel formula

$$\large{ r_h = \frac { w h } { w + 2h } }$$

Where:

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

$$\large{ h }$$ = depth of fluid

$$\large{ w }$$ = width of fluid