Prandtl number for air

The Prandtl number is a dimensionless number, defined as the ratio of kinematic viscosity (also called momentum diffusivity) to thermal diffusivity.

The formula is taken from IEC 60287-2-3.

Symbol
$\mathrm{Pr}_{air}$
Formulae
$0.715-2.5{\cdot}{10}^{-4} \theta_{at}$
Related
$\mathrm{Pr}_{gas}$
$\theta_{at}$