s law calculator to calculate flow rate through cylindrical pipes under laminar flow conditions. Calculate from pressure drop, radius, viscosity, and length.">

Poiseuille's Law Calculator

Free calculate flow rate through cylindrical pipes under laminar flow conditions using poiseuille's law.

Input Parameters

Water at 20°C: ~0.001 Pa·s

Results

Enter parameters to calculate flow rate

Poiseuille's Law Formula

Flow Rate

Q = (π × r⁴ × ΔP) / (8 × μ × L)

Where:

  • • Q = volumetric flow rate (m³/s)
  • • r = pipe radius (m)
  • • ΔP = pressure drop (Pa)
  • • μ = dynamic viscosity (Pa·s)
  • • L = pipe length (m)

Important Notes

• Valid only for laminar flow (Re < 2300)

• Flow rate proportional to r⁴ (very sensitive to radius)

• Assumes incompressible, Newtonian fluid

• Assumes steady, fully developed flow

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