# Hydraulic Radius of a Rectangular Channel

Written by Jerry Ratzlaff on . Posted in Fluid Dynamics

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

## Hydraulic Radius of a Rectangular Channel formula

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

### Where:

 Units English Metric $$\large{ r_h }$$ = hydraulic radius $$\large{ ft }$$ $$\large{ m }$$ $$\large{ h }$$ = depth of fluid $$\large{ ft }$$ $$\large{ m }$$ $$\large{ w }$$ = width of fluid $$\large{ ft }$$ $$\large{ m }$$ $$\large{ P_w }$$ = wetting perimeter $$\large{ ft }$$ $$\large{ m }$$

Tags: Hydraulic Equations