3.2.34 cw_tkachenko2 - Tkachenko-Mileikovskyi friction factor

f = cw_tkachenko2(d,e,re)

Calculate the Tkachenko-Mileikovskyi approximation of the Colebrook-White equation valid for and .

Arguments

d

Pipe internal diameter ().

e

Pipe effective roughness .

re

Reynolds number

Returns Darcy friction factor , dimensionless.

Possible Errors

Tkachenko-2 is only valid for 2320 <= Re <= 1e9

The given Reynolds number is out of range.

Tkachenko-2 is only valid for 0 <= e/D <= 0.65

The given pipe roughness/diameter fraction is out of range.

Tkachenko-2 diameter is <= 0

The given internal diameter of the pipe must be above zero.