H.M. Roder

SECOND AND THIRD VIRIAL COEFFICIENTS FOR HYDROGEN

Second and third virial coefficients for parahydrogen have been derived from closely spaced PVT data from 24 to 100 °K. They are in good agreement at 100 °K with published data for normal hydrogen. Analytical representations of the combined data from about 20 to 423 °K are presented which may be useful in computation of thermodynamic functions of the gas. These formulas are related to those resulting from the use of the Lennard-Jones potential.

The orthobaric densities of parahydrogen, derived heats of vaporization, and critical constants☆

Closely spaced experimental data are presented and used for defining a consistent set of values for critical constants that describe the two-phase boundaries between saturated liquid and saturated vapor. The heat of vaporization is derived. The various considerations affecting the selection of the critical temperatures are discussed. (C.E.S.)

The densities of saturated liquid hydrogen

Densities of para-hydrogen from l7 to 32 K are obtained by extrapolating newly determined compressed liquid isotherms to corresponding vapor pressures. Results are combined with earlier data for the range 14 to 20 f K and compared with normal hydrogen by means of densitytemperature relationships. (auth)

Pressure-density-temperature relations of freezing liquid parahydrogen to 350 atmospheres☆

Three new melting pressures for parahydrogen are utilized in an empirical, melting-line representation to obtain a provisional set of densities for liquid parahydrogen in equilibrium with solid parahydrogen. (C.E.S.)

The density and temperature dependence of the viscosity and thermal conductivity of dense simple fluids

Abstract This paper discusses the experimental information on the transport properties of dense simple fluids with emphasis on the compressed and saturated liquid states. Similarities and differences in the wide range density and temperature dependencies of the viscosity and thermal conductivity coefficients are summarized. The excess transport properties of argon, helium, hydrogen, oxygen, and carbon dioxide are graphically compared in the same reduced density and temperature ranges.

The thermal conductivity of liquid argon for temperatures between 110 and 140 K with pressures to 70 MPa

The paper presents new experimental measurements of the thermal conductivity of liquid argon for four temperatures between 110 and 140 K with pressures to 70 MPa and densities between 23 and 36 mol · L−1. The measurements were made with a transient hot-wire apparatus. A curve fit of each isotherm allows comparison of the present results to those of others and to correlations. The results are sufficiently detailed to illustrate several features of the liquid thermal conductivity surface, for example, the dependence of its curvature on density and temperature. If these details are taken into account, the comparisons show the accuracy of the present results to be 1 %. The present results, along with several other sets of data, are recommended for selection as standard thermal conductivity data along the saturated liquid line of argon, extending the standards into the cryogenic temperature range. The results cover a fairly wide range of densities, and we find that a hard-sphere model cannot represent the data within the estimated experimental accuracy.

The thermal conductivity surface for mixtures of methane and ethane

A correlation is presented for the extensive series of thermal conductivity measurements of binary methane-ethane mixtures. The composition dependences of the thermal conductivity in the dilute-gas region, dense-gas and liquid region, and critical region are discussed. The average absolute percentage deviation of the thermal conductivity surface as a function of temperature, density, and composition, from the experimental data, is 1.60%.

Heat capacity, Cp, of fluids from transient hot wire measurements

Abstract We report here the first thermal diffusivity measurements that cover a wide range of thermodynamic states including the dilute gas, the dense gas, the compressed liquid, and conditions close to the critical point. The heat capacity is obtained from simultaneous measurements of thermal conductivity and thermal diffusivity in a transient hot wire instrument, while the density is obtained from an equation of state. Values for the heat capacity, C p , of argon were obtained at two temperatures, 172 and 275 K, with pressures up to 70 MPa. For these temperatures the densities range from that of the dilute gas to 2.2 times critical density while the heat capacity varies by a factor of seven from the dilute gas value.

Transport properties of fluids of cryogenic interest

Abstract This Paper is a status report for viscosity and thermal conductivity data and correlations for pure fluids and fluid mixtures encountered in cryogenic process technology. Recommended correlations or tables of values are identified for each fluid. Specific data needs for future work are reported. Also presented are brief descriptions of the experimental techniques for viscosity and thermal conductivity measurements along with estimates of the associated experimental uncertainties.

Survey of current nbs work on properties of parahydrogen.

Subsequent to publication of the invaluable compilation of hydrogen properties by Woolley, Scott, and Brickwedde in 1948 [1], a greater-than-ever need developed for thermodynamic properties of parahydrogen at low temperatures and high pressures, where no data, existed. Many of the needed data have now been supplied by work at the CEL National Bureau of Standards. This report is designed to present a concise description of the various properties and to provide a bibliography of the original publications.