Colebrook-White

The Colebrook-White formula is used to evaluate the coefficient of friction losses in the pipes (Major head loss and linear losses), for all values ​​of the Reynolds number (flow regime)

• l is the major head loss coefficient,
• Re is the number of Reynolds
• e = roughness (average size of the roughness of the wall)
• D the pipe diameter

Mecaflux uses this equation for R_e > 10⁵

Colebrook charts giving the major losses coefficient (left ordinate) as a function of Reynolds number (x-axis) and the relative roughness (right ordinate)