Thermal diffusivity

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thermal diffusivity

(Also called heat conductivity, thermometric conductivity.) The ratio of the thermal conductivity k of a substance to the product of its specific heat c and its density ρ:

For a gas, c is the specific heat at constant pressure, cp. The thermal diffusivity determines the rate of heating given the temperature distribution according to an equation, which for one spatial dimension is
At a temperature of 0°C, the thermal diffusivity for air is 1.9 x 10-5 m2 s-1. At other temperatures, the ratio μ/K is nearly constant, where μ is the dynamic viscosity.
See also diffusivity, kinematic viscosity.

List, R. J. 1951. Smithsonian Meteorological Tables. 6th rev. ed., . 394–395.