SIMPLER FORMULAE FOR THE THERMAL DIFFUSION FACTOR OF BINARY GAS MIXTURES

1962 ◽  
Vol 40 (11) ◽  
pp. 1608-1613 ◽  
Author(s):  
S. C. Saxena ◽  
S. M. Dave ◽  
P. A. Pardeshi
Keyword(s):  
Molecular Weight ◽  
Thermal Diffusion ◽  
Weight Ratio ◽  
Numerical Calculations ◽  
Gas Mixture ◽  
View Point ◽  
Diffusion Factor ◽  
Thermal Diffusion Factor ◽  
Computational Labor ◽  
Binary Gas Mixture

Simpler formulae for the second approximation to the thermal diffusion factor of a binary gas mixture are derived according to both the approximation procedures of Chapman and Cowling, and Kihara. These formulae are much simpler than the rigorous theoretical formulae from the view point of computational labor. These new formulae are derived by expanding the rigorous expressions in powers of the molecular weight ratio, M, and deleting all those terms which contain explicitly the power of M higher than two. The accuracies of these simpler formulae are demonstrated by numerical calculations on gas systems as a function of both temperature as well as composition.

scholarly journals Simpler Formulae for the Chapman-Cowling Second Approximation to the Thermal Diffusion Factor of Binary Gas Mixtures

1964 ◽  
Vol 19 (3) ◽  
pp. 314-318
Author(s):  
R. K. Joshi ◽  
S. C. Saxena
Keyword(s):  
Molecular Weight ◽  
Thermal Diffusion ◽  
Gas Mixtures ◽  
Numerical Calculations ◽  
Gas Mixture ◽  
Diffusion Factor ◽  
Thermal Diffusion Factor ◽  
Binary Gas Mixture

A scheme has been proposed for approximating the complicated second and higher CHAPMAN-COWLING approximation formulae for the thermal diffusion factor of a binary gas mixture. Expressions have been reported for the second approximation and their accuracy investigated by performing numerical calculations for the systems Ar—Xe and He—Xe as a function of both temperature and composition. These formulae have been further simplified by expressing them in the ascending powers of M, the ratio of the molecular weight of the lighter component to the heavier component, and neglecting all those terms which explicitly posses the power of M greater than two. The two particular cases when either of the components is present in tracer amounts have also been investigated.

scholarly journals Thermal Diffusion Factor for Diatomic Gas Mixture in Multicomponent System

2000 ◽  
Vol 37 (4) ◽  
pp. 397-404 ◽  
Author(s):  
Hiroshi YAMAKAWA ◽  
Noboru KOBAYASHI ◽  
Youichi ENOKIDA ◽  
Ichiro YAMAMOTO
Keyword(s):  
Thermal Diffusion ◽  
Multicomponent System ◽  
Gas Mixture ◽  
Diffusion Factor ◽  
Thermal Diffusion Factor ◽  
Diatomic Gas

The stability of a layer of binary gas mixture heated below

1973 ◽  
Vol 57 (1) ◽  
pp. 103-110 ◽  
Author(s):  
M. L. Lawson ◽  
Wen-Jei Yang
Keyword(s):  
Thermal Diffusion ◽  
Soret Effect ◽  
Weight Ratio ◽  
Gas Mixture ◽  
Vertical Temperature ◽  
Dilute Gas ◽  
Binary Gas Mixture ◽  
Transfer Equations ◽  
The Stability ◽  
Thermal Diffusion Ratio

This paper investigates the Bénard problem in a binary mixture of dilute gases in which an imposed vertical temperature gradient induces a concentration gradient owing to the thermal diffusion effect. The transfer equations are derived by first-order perturbation theory which leads to instability criteria. Numerical results indicate that instability will set in only as stationary convection. This is distinctly different from the cases of liquids and concentrated gases, in which the thermal diffusion (or Soret) effect gives rise to oscillatory instability. It is disclosed in the study that the destabilization of the dilute gas-mixture layer is enhanced by an increase in the thermal diffusion ratio and/or the molecular weight ratio of the species.

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