Dynamic viscosity of gas mixtures

Abstract

An oscillating disc viscometer was designed and calibrated for the determination of viscosity of gases and gas mixtures at room temperature and pressure. The viscosity of oxygen, carbon dioxide and air were determined at room temperature and pressure with this viscometer and found to be within one per cent of the published data. The viscosity of five binary gas mixtures namely, Oxygen–Hydrogen, Oxygen–Nitrogen, Oxygen–Carbon dioxide, Carbon dioxide–Nitrogen, Carbon dioxide–Hydrogen and two ternary mixtures Oxygen–Nitrogen–Carbon dioxide and Oxygen–Hydrogen– Carbon dioxide were determined at room temperature and pressure using the oscillating disc viscometer. The experimental results for the binary mixtures and ternary mixtures were compared with Wilke’s theoretical equation. It was found that the present experimental results agreed with Wilke’s equations within 2% for the binary mixtures and within two per cent for the ternary mixtures. In the case of CO?–H?, the equation predicts values of viscosity which are 8–12% higher. The experimental results for CO?–N? compared with Saxena and Gambhir’s equation. In the case of CO?–N?, data obtained from Saxena and Gambhir’s equation was in very good agreement with the experimental data while for CO?–H? it deviated by as much as 5.8 per cent. In the case of the ternary gas mixture Oxygen–Carbon dioxide– Nitrogen, it was found that as long as the volumetric ratio of Oxygen to Carbon dioxide in the mixture was maintained at 11 to 8, the viscosity of the ternary mixture remained constant irrespective of the percentage of Nitrogen present in the mixture.