# Darcy friction factor - Brkić solution (Variable S)

## Description

In fluid dynamics, the Darcy friction factor formulae are equations that allow the calculation of the Darcy friction factor, a dimensionless quantity used in the Darcy–Weisbach equation, for the description of friction losses in pipe flow as well as open-channel flow.

The Darcy friction factor is also known as the Darcy–Weisbach friction factor, resistance coefficient or simply friction factor; by definition it is four times larger than the Fanning friction factor.

Brkić shows one approximation of the Colebrook equation based on the Lambert W-function.

The shown formula calculates the variable (S) in the Brkić solution

**See Also:**

## Variables

S | Variable in Brkić solution (dimensionless) |

Re | Reynolds number (dimensionless) |