Manning formula

Input(s)

$\mathrm{k}$: Conversion factor of $(\mathrm{L} 1 / 3) / \mathrm{T}, 1$ for $\mathrm{SI}((\mathrm{m} 1 / 3) / \mathrm{s})$

$\mathrm{Rh}$: Hydraulic radius $(\mathrm{m})$

S: Slope of the hydraulic grade line or the linear $\left(\mathrm{kg} / \mathrm{m}^{3}\right)$

$\mathrm{n}$: Manning coefficient (dimensionless)

Output(s)

V: Cross-sectional average velocity $(\mathrm{m} / \mathrm{s})$

Formula(s)

$$ V=k * R h^{\frac{2}{3}} * \frac{S^{\frac{1}{2}}}{n} $$

Reference(s)

Wikipedia.org.