Péclet number

One of the characteristic numbers for processes of convective heat transfer. The Péclet number characterizes the relation between the convective and molecular heat-transport processes in a flow of liquid:

where is the characteristic linear scale of the heat-transfer surface, is the velocity of the liquid relative to that surface, is thermal diffusion coefficient, is the heat capacity at constant pressure, is the density, and is the thermal conductivity coefficient.

The Péclet number is related to the Reynolds number and the Prandtl number by .

It is named after J. Péclet.