EngiRef / Fluids Engineering Formula

Darcy-Weisbach Equation

Darcy-Weisbach Equation: Head loss due to friction in pipe flow. A Pipe Flow formula in fluids engineering. Variables hf, f, L, D, v and g, each with SI and…

Pipe Flow

Specification

Name
Darcy-Weisbach Equation
Discipline
fluids
Category
Pipe Flow
LaTeX
h_f = f \frac{L}{D} \frac{v^2}{2g}
Description
Head loss due to friction in pipe flow
Conditions
Steady, incompressible, fully developed flow; f is Darcy friction factor
Can solve for
hf, f, L, D, v
Tags
darcy, weisbach, friction, head loss, pipe

Variables

Variables for Darcy-Weisbach Equation
SymbolNameUnitSi UnitImperial Unit
hfHead Lossmmft
fFriction Factor - - -
LPipe Lengthmmft
DPipe Diametermmft
vFlow Velocitym/sm/sft/s
gGravitym/s²m/s² -

Common questions

What is the Darcy-Weisbach Equation formula?
Head loss due to friction in pipe flow. It sits under Pipe Flow, Fluids engineering in the EngiRef reference.
What do the symbols in the Darcy-Weisbach Equation formula mean?
In Darcy-Weisbach Equation, hf is head loss in m; f is friction factor; L is pipe length in m; D is pipe diameter in m; v is flow velocity in m/s; g is gravity in m/s².
When does the Darcy-Weisbach Equation formula apply?
Darcy-Weisbach Equation holds under this condition: Steady, incompressible, fully developed flow; f is Darcy friction factor.