Manning's Roughness Coefficient

Written by Jerry Ratzlaff on . Posted in Fluid Dynamics

Manning's Roughness Coefficient Formula

\(\large{ n =  \frac{1.49 \; r_h^{0.66} \; S^{0.5} }   {v}       }\)     (Manning Equation)

Where:

\(\large{ n }\) = Manning roughness coefficient

\(\large{ v }\) = flow velocity in a channel, culvert, or pipe

\(\large{ S }\) = channel slope or energy slope line

\(\large{ r_h }\) = hydraulic radius

\(\large{ k }\) = unit conversion factor (\(k = 1.49\) English units ft/sec) (\(k = 1.0\) SI units m/sec)

 

Tags: Equations for Flow Equations for Hydraulic