Methods of calculating thermal conductivity of binary mixtures involving polyatomic gases

Recent experimental measurements of the thermal conductivity of mixtures of nitrogen and hydrogen are compared with values calculated from Hirschfelder’s theory of the transport of heat in mixtures of polyatomic gases. The discrepancies between theory and observation, though small, appear to be greater than the experimental error; the observed thermal conductivities almost always exceed the theoretical values. Similar small discrepancies have been reported in some other experimental work. It is shown that for mixtures of nitrogen and hydrogen the discrepancies are unlikely to be due to a failure to assign correct values to the parameters appearing in the theroretical equations. Attention is therefore drawn to the validity of the assumptions underlying the theory. Hirschfelder’s theory distinguishes translational and internal contributions to the conductivity of the mixture. It rests on the assumption, originally due to Eucken, that the translational contributions to the thermal conductivity of the individual constituents may be calculated as if the gases were monatomic, i.e. by setting K trans. = 2·5 nc v trans. .It is suggested that this is an overestimate of the translational contribution and that complete accuracy is therefore not to be expected from calculations based on Hirschfelder’s theory. A recent theoretical study by Mason & Monchick is in accord with this suggestion.

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Rotational relaxation and the relation between thermal conductivity and viscosity for some nonpolar polyatomic gases

Symposium (International) on Combustion ◽

10.1016/s0082-0784(63)80080-6 ◽

1963 ◽

Vol 9 (1) ◽

pp. 725-732 ◽

Cited By ~ 1

Author(s):

R.S. Brokaw ◽

C. O'Neal

Keyword(s):

Thermal Conductivity ◽

Rotational Relaxation ◽

Polyatomic Gases

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New Results on the Thermal Conductivity of the Noble Gases and of Two Binary Mixtures

Thermal Conductivity 16 ◽

10.1007/978-1-4684-4265-6_46 ◽

1983 ◽

pp. 537-547

Author(s):

Joseph Kestin ◽

Richard Fleeter ◽

W. A. Wakeham

Keyword(s):

Thermal Conductivity ◽

Binary Mixtures ◽

Noble Gases

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Simulation of thermal conductivity of rare gases by the stochastic method

Proceedings of the Russian higher school Academy of sciences ◽

10.17212/1727-2769-2021-1-19-29 ◽

2021 ◽

pp. 19-29

Keyword(s):

Thermal Conductivity ◽

Molecular Dynamics ◽

Molecular Modeling ◽

Transfer Process ◽

Thermal Conductivity Coefficient ◽

Rarefied Gas ◽

Molecular Dynamics Method ◽

Gas Transfer ◽

Polyatomic Gases ◽

Dynamics Method

One of the main successes of the kinetic theory of gases is the explicit calculation of the transport coefficients of rarefied gases. However, the greatest problems arise when calculating the thermal conductivity coefficient, especially for polyatomic gases. Also, when using different potentials, it is necessary to systematically calculate the so-called Ω-integrals, which in itself is a rather difficult task. For this reason, direct numerical molecular modeling of the processes of transfer of rarefied gases, in particular, the calculation of their transfer coefficients, is also relevant. A well-known method for such modeling is the molecular dynamics method. Unfortunately, until now this method is not available for modeling the processes of rarefied gas transfer. Under nor-mal conditions, the simulation cell should contain tens or even hundreds of millions of molecules during calculations. At the same time, the numerical implementation of the molecular dynamics method is accompanied by a systematic appearance of errors, which is the reason for the appearance of dynamic chaos. With this simulation, the true phase trajectories of the system under consideration cannot be obtained. Therefore, naturally, the idea of developing a method for modeling transport processes arises, in which phase trajectories are not calculated based on Newton's laws, but are simulated, and then are used to calculate any observables. In our works, we developed a method of stochastic molecular modeling (STM) of rarefied gas transfer processes, where this idea was implemented. The efficiency of the SMM method was demonstrated by calculating the coefficients of self-diffusion, diffusion, and viscosity of both monoatomic gases and polyatomic gases. At the same time, the possibility of modeling the most complex transfer process – the energy transfer process – has not yet been considered. This work aims to simulate the thermal conductivity coefficient by the SMM method. Both monoatomic (Ar, Kr, Ne, Xe) and polyatomic gases (CH4, O2) were considered.

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