Chézy formula

In fluid dynamics, the Chézy formula describes the mean flow velocity of steady, turbulent open channel flow:

where

The formula is named after Antoine de Chézy, the French hydraulics engineer who devised it in 1775.

This formula can also be used with Manning's Roughness Coefficient, instead of Chézy's coefficient. Manning derived the following relation to C based upon experiments:

where

Unlike the Manning equation, which is empirical, the Chézy equation is derived from hydrodynamics theory.

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