Peclet number, or officially known as Péclet number, is a dimensionless number that represents the ratio of advection and diffusion caused by heat transfer.
It can be expressed in the following equation:
Pe : Péclet number
U : Characteristic speed [m/s]
L : Characteristic length [m]
α : Thermal diffusivity [m2/s]
Péclet number is named after the French physicist Jean Claude Eugène Péclet.