Reynolds Number Rechner — Formel
## Reynolds Number
The Reynolds number is a dimensionless quantity that predicts whether fluid flow will be laminar or turbulent.
### Formula
**Re = V D / nu**
where V is the mean velocity, D is the pipe inner diameter, and nu is the kinematic viscosity. For pipe flow: Re < 2300 is laminar, 2300 < Re < 4000 is transitional, and Re > 4000 is turbulent.
The Reynolds number is a dimensionless quantity that predicts whether fluid flow will be laminar or turbulent.
### Formula
**Re = V D / nu**
where V is the mean velocity, D is the pipe inner diameter, and nu is the kinematic viscosity. For pipe flow: Re < 2300 is laminar, 2300 < Re < 4000 is transitional, and Re > 4000 is turbulent.
Lösungsbeispiel
Water at 20 deg C (nu = 1e-6 m^2/s) flowing at 2 m/s through a 100 mm pipe.
- Re = 2 x 0.1 / 1e-6 = 0.2 / 1e-6 = 200,000
- Since 200,000 >> 4000, flow is fully turbulent.