Thermal Diffusivity

Written by Jerry Ratzlaff on . Posted in Thermodynamics

Thermal diffusivity, abbreviated as $$\alpha$$ (Greek symbol alpha), is a measure of the transient thermal reaction of a material to a change in temperature.

Thermal diffusivity formula

$$\large{ \alpha = \frac{ k }{ \rho \; Q } }$$
Symbol English Metric
$$\large{ \alpha }$$  (Greek symbol alpha) = thermal diffusivity  $$\large{\frac{ft^2}{sec}}$$ $$\large{\frac{m^2}{s}}$$
$$\large{ \rho }$$  (Greek symbol rho) = density $$\large{\frac{lbm}{ft^3}}$$ $$\large{\frac{kg}{m^3}}$$
$$\large{ Q }$$ = specific heat capacity $$\large{\frac{Btu}{lbm-F}}$$ $$\large{\frac{kJ}{kg-K}}$$
$$\large{ k }$$ = thermal conductivity $$\large{\frac{Btu}{hr-ft^2-F}}$$  $$\large{\frac{W}{m-K}}$$