Thermal Diffusivity

Written by Jerry Ratzlaff on . Posted in Thermodynamics

Thermal diffusivity, abbreviated as αD (Greek symbol alpha with a subscript D), is a measure of the transient thermal reaction of a material to a change in temperature. This is different than the the thermal diffusivity tensor which is abbreviated as α (Greek symbol alpha [note no subscript]).

Thermal Diffusivity formula

\(\large{ \alpha_D = \frac {k_t} {p \;  Q }     }\)         


\(\large{ \alpha_D }\)  (Greek symbol alpha) = thermal diffusity [m2/s or ft2/s]

\(\large{ p }\) = density

\(\large{ Q }\) = specific heat capacity

\(\large{ k }\) = thermal conductivity

Solve for:

\(\large{ p = \frac {k} {\alpha \;  Q}     }\)

\(\large{ Q = \frac {k} {\alpha  \;   p}     }\)

\(\large{ k =   \alpha \;  p   \;  Q   }\)


Tags: Equations for Thermal Equations for Heat