3.2.17 chen - Chen friction factor

f = chen(d,e,re)

Calculate the Chen approximation of the Colebrook-White equation for .

Arguments

d

Pipe internal diameter ().

e

Pipe effective roughness .

re

Reynolds number

Returns Darcy friction factor , dimensionless.

Possible Errors

Chen friction approximation only valid for 4000 <= Re <= 4e8

The given Reynolds number is out of range.