
If you are using the gas law (as described in Section 8.3), you have the option to define the thermal conductivity using kinetic theory as
where is the universal gas constant, is the molecular weight, is the material's specified or computed viscosity, and is the material's specified or computed specific heat capacity.
To enable the use of this equation for calculating thermal conductivity, select kinetictheory from the dropdown list to the right of Thermal Conductivity in the Materials panel. The solver will use Equation 8.55 to compute the thermal conductivity.