# Hydraulic Radius of a Triangular 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 Triangular Channel formula

$$\large{ r_h = \frac { A_c } { P } }$$

$$\large{ r_h = \frac { z\;h^2 } { 2\;h \; \sqrt {1 \;+\; z^2 } } }$$

Where:

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

$$\large{ b }$$ = bottom width of fluid

$$\large{ A_c }$$ = area cross-section of flow

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

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

$$\large{ P }$$ = wetted perimeter

$$\large{ z }$$ = width of channel slope