pyrcel.thermo.ka

pyrcel.thermo.ka(T, rho, r)

Thermal conductivity of air, modified for non-continuum effects.

The thermal conductivity of air is given by

\[\begin{equation} k_a = 10^{-3}(4.39 + 0.071T) \tag{SP2006, 17.71} \end{equation}\]

Modification to account for non-continuum effects (small aerosol/droplet size) yields the equation

\[\begin{equation} k'_a = \frac{k_a}{1 + \frac{k_a}{\alpha_t r_p \rho C_p} \frac{2\pi M_a}{RT}^{1/2}} \tag{SP2006, 17.72} \end{equation}\]

where \(\alpha_t\) is a thermal accommodation coefficient (constants.at).

Parameters:

T : float

ambient air temperature, K

rho : float

ambient air density, kg/m^3

r : float

droplet radius, m

Returns:

float

\(k'_a(T, \rho, r)\) in J/m/s/K

See also

ka_cont
neglecting correction for non-continuum effects

References

[SP2006]Seinfeld, John H, and Spyros N Pandis. Atmospheric Chemistry and Physics: From Air Pollution to Climate Change. Vol. 2nd. Wiley, 2006.