Darcy Friction Factor
It has been observed that the pressure drop is proportional to the pipe length to diameter ratio. This allows the equation for the pressure drop from the previous page to be rewritten as
The relationship, F, between the Reynolds number and the relative roughness is defined by a parameter, f, called the Darcy friction factor
The Darcy friction factor for laminar flow can be determined analytically and give by the equation
Experimental measurements were conducted by Colebrook to determine the Darcy friction factor for turbulent flows. One form of the Colebrook equation is
Learn the definition of the Darcy friction factor.