Fluid Mechanics
Advanced

Reynolds Number

Predicts laminar vs turbulent flow.

Formula

Re=ρvLμRe = \frac{\rho v L}{\mu}

Variables

\rhoDensity
vSpeed
LLength
\muViscosity

Example

Re < 2300 ⇒ laminar

Did You Know?

The Reynolds number predicts when smooth flow turns turbulent, a threshold that troubles engineers and swimmers alike.

reynoldsturbulenceflow