# Thermal diffusivity

In heat transfer analysis, thermal diffusivity (symbol: [itex]\alpha[itex]) is the ratio of thermal conductivity to heat capacity.

[itex]\alpha = {k \over {\rho c_p}}[itex]

where

k is thermal conductivity, measured in watts per metre-kelvin

ρcp is the volumetric heat capacity, measured in joules per cubic metre-kelvin

The SI units 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'.de:Temperaturleitfähigkeit

• Art and Cultures
• Countries of the World (http://www.academickids.com/encyclopedia/index.php/Countries)
• Space and Astronomy