Thermal diffusivity
From Freepedia
In heat transfer analysis, thermal diffusivity (symbol: <math>\alpha</math>) is the ratio of thermal conductivity to volumetric heat capacity.
- <math>\alpha = {k \over {\rho c_p}}</math>
where
k is thermal conductivity (SI units: watts per metre-kelvin)
ρcp is the volumetric heat capacity (density times specific heat capacity; SI units: joules per cubic metre-kelvin)
The SI units for thermal diffusivity are square metres per second or m²/s.
Substances with high thermal diffusivity rapidly adjust their temperature to that of their surroundings, because they conduct heat quickly in comparison to their thermal 'bulk'.
