Investigation on the Rheological Behavior of Multigrade Oil under the Effect of Organic and Inorganic Impurities

B. Belahcene, A. Mansri, A. Benmoussat


The lubrication process of mechanical equipment and treatment of assembly metals structures using fluids with efficient rheological properties requires a knowledge of their behavior in the presence and in the absence of organic impurities. The intrinsic physical property of the lubricating fluids has a dependency to the mechanical and physicochemical environment. This paper is focused on the assessment of the behavior of SAE20W40 multigrade oil under normal temperature and pressure, through the addition of water in vapor phase and solid paraffin. Results show that there is a decrease in the dynamic and kinematic viscosity for heterogeneous oils. The rate of degradation is greater in the mixture of water with oil. The addition of paraffin in the mixture caused an increase in viscosity. However, after certain RPM points, it is noted that the data curve became similar to the first mixture. This relaxation phenomenon is caused by the turbulence created by the rotating cylinder in oil. The use of a retentate paraffin shows that the added agent has acted as a surfactant


Viscosity; oil; water; relaxation; paraffin; miscibility

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