Darcy Friction Factor
The Darcy friction factor, often denoted by f, is a dimensionless parameter used in fluid mechanics to characterize the resistance to flow in a pipe or conduit.
The Darcy friction factor is commonly used in the Darcy-Weisbach equation, which relates the pressure drop or head loss in a pipe to the flow rate, pipe diameter, and fluid properties.
Darcy friction factor is proportional to shear stress at pipe/conduit wall as number of velocity heads and is used in momentum transfer in general and turbulent flow calculations in particular. It is equivalent to (4) times Fanning’s friction factor. It is normally defined in one of the following forms
or
or
Where: | ||
d | = | Diameter |
delta-P | = | Pressure drop |
dP/dL | = | Pressure drop per unit length |
gc | = | Dimensional constant |
G | = | Mass velocity |
L | = | Length |
rho | = | Density |
V | = | Velocity |
The Darcy friction factor depends on various factors such as the Reynolds number, relative roughness of the pipe, and flow regime. It’s typically determined using empirical correlations or obtained from friction factor charts for specific flow conditions.
The Darcy friction factor is crucial in determining the energy losses associated with fluid flow in pipes and is widely used in the design and analysis of piping systems, HVAC systems, and hydraulic networks. It plays a significant role in optimizing system performance and ensuring efficient fluid transport.
