THERMAL CONDUCTIVITY OF METHANE AT ATMOSPHERIC PRESSURE IN THE TEMPERATURE RANGE OF 360-1275 K.

Thermal conductivity of a research grade pure methane sample is measured in a hot-wire column instrument in the temperature range 360-1275 K from heat transfer rate data taken in the continuum region. The results are correlated by a quadratic polynomial in temperature viz. , k(T) equals minus 23. 35 plus 0. 1698T plus 1. 893 multiplied by 10** minus **5T**2. Here k is in mW/m-K and T in K. The experimental data are compared with the available conductivity values and with the predictions of kinetic theories of polyatomic gases in conjunction with realistic intermolecular potentials. The conductivity data are also employed to compute the diffusion coefficient for vibrational energy. The effect of gaseous radiative transfer on the measured thermal conductivity of methane is estimated by comparing the conductivity coefficients of a slab of gas with and without the presence of the absorption bands.