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.

$$\large{ r_h = \frac{ A_c }{ P_w } }$$
$$\large{ r_h }$$ = hydraulic radius  $$\large{ ft }$$ $$\large{ m }$$
$$\large{ A_c }$$ = area cross-section of flow $$\large{ ft^2 }$$ $$\large{ m^2 }$$
$$\large{ P_w }$$ = wetting perimeter $$\large{ ft }$$ $$\large{ m }$$