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Reynolds number predicts flow regime: laminar (smooth, orderly) or turbulent (chaotic, mixing). It's dimensionless and crucial for fluid mechanics analysis.

Formule

The calculator applies Re = (ρ × v × L) / η

Re: (ρ × v × L) / η — (ρ × v × L) / η
L: L value — Variable used in the calculation

Guide étape par étape

1Enter fluid density, velocity, characteristic length, and dynamic viscosity
2The calculator applies Re = (ρ × v × L) / η
3Results classify flow and predict behavior

Exemples résolus

Entrée

ρ = 1000 kg/m³, v = 0.1 m/s, L = 0.01 m (water in small pipe), η = 0.001 Pa·s

Résultat

Re = 1000 (laminar)

Smooth, predictable flow

Erreurs courantes à éviter

✕Confusing characteristic length (diameter for pipes, chord for airfoils)
✕Using kinematic instead of dynamic viscosity

Questions fréquentes

What Reynolds numbers indicate turbulence?

Re < 2300 is laminar, 2300-4000 is transitional, Re > 4000 is turbulent in pipes.

Does Reynolds number apply to all fluids?

Yes, it's dimensionless; the same Re value predicts similar flow behavior regardless of fluid type.

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