what does thermal diffusivity mean
Thermal Diffusivity. a physical parameter of a substance that characterizes the rate of change of its temperature in transient thermal processes. Thermal diffusivity is a measure of the thermal-inertia properties of a substance. It is numerically equal to the ratio of the substanceâs thermal conductivity and the product of its specific heat (at constant pressure) and density. Thermal diffusivity is expressed in m 2 /sec.