1977 Volume 10 Issue 2 Pages 83-88
The viscosities of three binary gaseous mixtures N2 + He, N2+CClF3 (R13) and N2+CHCIF2 (R22), have been measured at 25°, 50° and 75°C over a range of pressures from the atmospheric to about 8 bar. The measurements were performed by a rolling-ball viscometer in the laminar flow region on a relative basis. The calibration curves were prepared using N2 and H2 at the experimental conditions. The uncertainty in the viscosity should be smaller than 0.5 percent.
The viscosity of the nonpolar gas system, N2+He, increases with pressure throughout the experimental temperatures in the same manner as nonpolar pure gases. However, the mixtures containing one polar gas, N2+CClF3 and N2+CHC1F2, behave anomalously at the lowest temperature, 25°C, where the viscosity decreases slightly with increasing pressure.
The experimental viscosity values were used to evaluate three expressions presented by Bird-Hirschfelder-Curtiss, Wilke and Brokaw for the estimation of the viscosity of gas mixtures.