EngiRef / Fluids Engineering Formula

Hagen-Poiseuille Equation

Hagen-Poiseuille Equation: Volumetric flow rate for laminar pipe flow. A Pipe Flow formula in fluids engineering. Variables Q, ΔP, d, μ and L, each with SI and…

Pipe Flow

Specification

Name
Hagen-Poiseuille Equation
Discipline
fluids
Category
Pipe Flow
LaTeX
Q = \frac{\pi \Delta P d^4}{128 \mu L}
Description
Volumetric flow rate for laminar pipe flow
Conditions
Laminar flow (Re < 2300), fully developed
Can solve for
Q, ΔP, d, L
Tags
hagen, poiseuille, laminar, flow, viscous

Variables

Variables for Hagen-Poiseuille Equation
SymbolNameUnitSi UnitImperial Unit
QFlow Ratem³/sm³/sft³/s
ΔPPressure DropPaPapsi
dPipe Diametermmin
μDynamic ViscosityPa·sPa·s -
LPipe Lengthmmft

Common questions

What is the Hagen-Poiseuille Equation formula?
Volumetric flow rate for laminar pipe flow. It sits under Pipe Flow, Fluids engineering in the EngiRef reference.
What do the symbols in the Hagen-Poiseuille Equation formula mean?
In Hagen-Poiseuille Equation, Q is flow rate in m³/s; ΔP is pressure drop in Pa; d is pipe diameter in m; μ is dynamic viscosity in Pa·s; L is pipe length in m.
When does the Hagen-Poiseuille Equation formula apply?
Hagen-Poiseuille Equation holds under this condition: Laminar flow (Re < 2300), fully developed.