Moody Friction Factor

Dimensionless parameter applied by the Darcy – Weisbach equation that quantifies the friction loss incurred for a certain fluid, flow velocity, pipe size and length.

Calculation of friction factor is dependent on flow regime:

Laminar Flow:

f_D = 64/Re

Turbulent Flow (Colebrook (a) / Haaland (b) Equation):

1/√(f)=-2 Log [ε/3.7D+2.51/(Re√f)]     

1/√(f)=- Log [(ε/3.7D)^{1.11}+2.51/Re]     

Haaland equation is used when the user selects the non-iterative solution for friction factor calculation in the Calculation options.

Where:

For systems where flow regime falls within transition, a linear interpolation using the friction factor at the Reynolds number where laminar flow terminate and turbulent regime start is applied.