The viscosity of some fluorocarbons in the vapour phase

Abstract

Measurements have been made of the temperature coefficients of viscosity of the vapours of tetrafluoro-ethylene, hexafluoro-ethane, perfluoro-n-pentane and perfluoro-nhexane. For all of these vapours the temperature coefficients of viscosity are smaller than those for the corresponding hydrocarbons. This has been interpreted in terms of the intermolecular forces between fluorocarbon molecules which change steeply with the distance between molecular centres.

Models for viscosity, thermal conductivity, and surface tension of selected pure fluids as implemented in REFPROP v10.0

“…These data appeared to differ significantly from the other sources and were not used in the regression to obtain the parameters in Table 2, but are shown in the deviation plot given in Figure 161. One source of gas-phase viscosity data was found (J. C. McCoubrey & Singh, 1960). We estimate the uncertainty of the viscosity in the liquid phase at atmospheric pressure above 230 K is 5 %, rising to 10 % at pressures to 40 MPa; the uncertainty in the gas phase is also 5 %.…”

“…The Lennard-Jones coefficients were estimated by scaling the values from McCoubrey and Singh (J. C. McCoubrey & Singh, 1960) for perfluoropentane, using the relationships from Chung et al (Chung et al, 1988) (ε/kB scales with Tc, σ scales with Vc 1/3 ). No viscosity data were found.…”

“…The Lennard-Jones coefficients were taken from McCoubrey and Singh (J. C. McCoubrey & Singh, 1960). Viscosity data are extremely limited; only one set of liquid data at atmospheric pressure by Burger and Cady (Burger & Cady, 1951) was found, and used to obtain the coefficients in Table 2.…”

“…The Lennard-Jones coefficients were taken from McCoubrey and Singh (J. C. McCoubrey & Singh, 1960). Several sources of liquid-phase viscosity data were found (Cochran et al, 1974;M.G.…”

Molecular Transport Properties of Fluids. Chemical Engineering Fundamentals Review

“…(50), and to nitrogen-COz mixtures at 20' C. and 1 to 21 atm. The temperature coefficient of viscosity for fluorocarbon vapors was found by McCoubrey and Singh (70) to be 10 to 20% lower than for the corresponding hydrocarbons. Data for helium are not dependent on pressure, and the temperature depend-G data even for the hydrocarbons at high ence is best described by Buckingham's exponential-6 potential.…”