MAXScanner thermal & fluid engineering
Péclet Number Calculator — Advection vs Diffusion
Calculate thermal or mass Péclet number from velocity, characteristic length and diffusivity, with interpretation of transport dominance.
Last updated: September 17, 2026
Results
Enter non-negative velocity/length and positive diffusivity
Formula, example and assumptions
Pe=vL/α (thermal) or vL/D_m (mass).
v=1 m/s, L=0.1 m and α=1e-5 m²/s gives Pe=10,000.
- Use thermal diffusivity for heat transport and mass diffusivity for species transport.
- Characteristic length must match the modeled geometry.
Frequently asked questions
What does a high Péclet number mean?
Advection dominates diffusion over the chosen length scale.
Is Péclet number dimensionless?
Yes; vL and diffusivity have the same dimensions.