Thermal conductivity, linear function of T

Presentation

This model defines a conductivity k as a linear function of the temperature for an isotropic or anisotropic material.

Mathematical model

The conductivity is a linear function of the temperature.

The corresponding mathematical formula is written:

k(T) = k_a(1 + a (T - T₀))

where:

• T₀ is the reference temperature (degree)
• k_a is the thermal conductivity of a material at T₀ (W/m/degree)
• a is a coefficient (positive or negative) (degree^-1)

The shape of k(T) curve is presented in the figure below.

Anisotropic material

For an anisotropic material, this linear model consists of a group of three straight lines.