TY - JOUR
T1 - Viscosity of gaseous mixtures of HFC-134a (1,1,1,2-tetrafluoroethane) + HFC-32 (difluoromethane)
AU - Yokoyama, C.
AU - Nishino, T.
AU - Takahashi, M.
N1 - Funding Information:
The authors acknowledge suggestions of an anonymous reviewer which improved the manuscript significantly. This study was supported from the research project entitled ‘‘Infrastructure development of thermo-physical properties data for future industries’’ organized by Japan Space Utilization Promotion Center (JSUP) and New Energy Industrial Technology Development Organization (NEDO), which is gratefully acknowledged.
PY - 2004/1
Y1 - 2004/1
N2 - This paper reports experimental results for the viscosity of gaseous mixtures of HFC-134a (1,1,1,2-tetrafluoroethane) + HFC-32 (difluoromethane). The measurements were carried out with an oscillating-disk viscometer of the Maxwell type at temperatures from 298.15 to 423.15 K. The viscosity was measured for three mixtures containing 25.00, 52.40, and 74.98 mole% HFC-134a in HFC-32. Experimental results for the viscosity at normal pressures show a minimum as plotted against mole fraction in the higher temperature region, which may be the first experimental observation of the minima for dilute binary gaseous mixtures of HFCs. The viscosity at normal pressures was analyzed with the extended law of corresponding states developed by Kestin et al., and the scaling parameters were obtained for unlike-pair interactions between HFC-32 and HFC-134a. The modified Enskog theory developed by Vesovic and Wakeham was applied to predict the viscosity for the binary gaseous mixtures under pressure. As for the calculation of pseudo-radial distribution functions in mixtures, a method based on the equation of state for hard-sphere fluid mixtures proposed by Carnahan-Starling was applied.
AB - This paper reports experimental results for the viscosity of gaseous mixtures of HFC-134a (1,1,1,2-tetrafluoroethane) + HFC-32 (difluoromethane). The measurements were carried out with an oscillating-disk viscometer of the Maxwell type at temperatures from 298.15 to 423.15 K. The viscosity was measured for three mixtures containing 25.00, 52.40, and 74.98 mole% HFC-134a in HFC-32. Experimental results for the viscosity at normal pressures show a minimum as plotted against mole fraction in the higher temperature region, which may be the first experimental observation of the minima for dilute binary gaseous mixtures of HFCs. The viscosity at normal pressures was analyzed with the extended law of corresponding states developed by Kestin et al., and the scaling parameters were obtained for unlike-pair interactions between HFC-32 and HFC-134a. The modified Enskog theory developed by Vesovic and Wakeham was applied to predict the viscosity for the binary gaseous mixtures under pressure. As for the calculation of pseudo-radial distribution functions in mixtures, a method based on the equation of state for hard-sphere fluid mixtures proposed by Carnahan-Starling was applied.
KW - Binary mixture
KW - Corresponding states
KW - Enskog theory
KW - HFC-134a
KW - HFC-32
KW - Mixture model
KW - Viscosity
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U2 - 10.1023/B:IJOT.0000022328.47209.20
DO - 10.1023/B:IJOT.0000022328.47209.20
M3 - Article
AN - SCOPUS:3543085717
VL - 25
SP - 71
EP - 88
JO - International Journal of Thermophysics
JF - International Journal of Thermophysics
SN - 0195-928X
IS - 1
ER -