THERMAL-CONDUCTIVITY OF MIXTURES OF HYDROGEN AND HELIUM AT 27.5-DEGREES-C AND PRESSURES UP TO 14 MPA

A report is presented of new, absolute measurements of the thermal conductivity of three binary gaseous mixtures of hydrogen and helium at 27. 5 degree C and at pressures up to 14 MPa. The measurements were performed in a transient hot-wire instrument and have an estimated accuracy of plus or minus 0. 3%. The experimental results for each mixture have been extrapolated so as to yield reliable values of the zero-density thermal conductivity. These data are described, within their experimental uncertainty, by the Hirschfelder-Eucken formula provided that an empirical adjustment is made to one of the parameters characteristic of the unlike molecular interaction. With the aid of the same formula the data are shown to be consistent with earlier viscosity data on the same system.