Calculation of the transport properties of carbon dioxide. III. Volume viscosity, depolarized Rayleigh scattering, and nuclear spin relaxation

Abstract

Transport properties of pure carbon dioxide have been calculated from the intermolecular potential using the classical trajectory method. Results are reported in the dilute-gas limit for volume viscosity, depolarized Rayleigh scattering, and nuclear spin relaxation for temperatures ranging from 200 to 1000 K. Three recent carbon dioxide potential energy hypersurfaces have been investigated. Calculated values for the rotational collision number for all three intermolecular surfaces are consistent with the measurements and indicate that the temperature dependence of the Brau-Jonkman correlation is not applicable for carbon dioxide. The results for the depolarized Rayleigh scattering cross section and the nuclear spin relaxation cross section show that calculated values for the generally more successful potentials differ from the observations by 9% at about 290 K, although agreement is obtained for nuclear spin relaxation at about 400 K.

Abinitiocalculations of the spectral shapes of CO2isolated lines including n

“…We have used a CO 2 molar mass of M = 44 g/mole, a C-O bond length of 1.16Å, and retained the CO 2 -CO 2 site-site anisotropic potential energy surface of [30]. As shown in [32,33,[35][36][37][39][40][41], the latter leads to very satisfactory predictions of numerous CO 2 properties. Using these data, rCMDS have been made on the IBM Blue Gene/P computer of the Institut du Développement et des Ressources en Informatique Scientifique.…”

Calculation of thermophysical properties for CO2gas using anab initiopotential model

“…Based on different molecular potential models, a number of calculations for the CO 2 thermophysical properties were carried out in the last decade [1][2][3][4][5][6]. Bock et al [1][2][3] calculated accurately the transport properties of CO 2 at the zero density limit by evaluating the relevant collision cross sections by means of classical-trajectory calculations directly from ab initio potentials. However, their calculation method so far cannot be extended to the calculation of transport properties for dense fluids.…”

Calculation of the transport and relaxation properties of methane. II. Thermal conductivity, thermomagnetic effects, volume viscosity, and nuclear-spin relaxation

“…The accurate calculation of the transport and relaxation properties of simple molecular gases directly from the intermolecular potential energy hypersurface has recently become possible. [1][2][3][4][5][6][7][8] These calculations provide not only a stringent test of the accuracy of the potential surface but also an accurate data set at low and high temperatures, where experimental data are more difficult to measure and hence are of lower accuracy or non-existent. For methane, which is relevant to a wide variety of topical issues including climate change and energy sustainability and may even have been observed 9 on an exoplanet, the provision of accurate transport and relaxation properties is important since this reduces the uncertainty in modelling processes where methane properties play a major role.…”

“…In the present paper we report on calculations for thermal conductivity, thermo-magnetic coefficients, volume viscosity, and nuclear-spin relaxation. As methane has an isotropic polarizability, no Depolarized Rayleigh light scattering measurements, available for other molecules studied, 1,4,8 are possible. Thus this work completes the evaluation of transport and relaxation properties of methane.…”