Nanofluids made by the addition of nanoparticles to the base lubricant have shown promising applications in the industrial world, such as automobile industry. Recently, mineral based lubricants have been replaced by vegetable based oils regarding to their environmental benignancy. Besides, some authors have discussed the tribological behavior of lubricants containing copper oxide nanoparticles, which resulted an excellent friction and antiwear performance. In this paper, two kinds of fluid, including mineral and rapeseed base oils, were assumed as the base lubricants, and CuO nanoparticles as the additives making nano-lubricants. Then the oils were analyzed in terms of viscosity, density and idone value. The effects and role of different factors on viscosity of nano fluids were concentrated and studied using a Brookfield viscometer. the viscosity of rapeseed oil as bio-lubricant with/without CuO NPs as additives at different concentrations 0.1, 0.2, 0.5 and 1 Wt% at two constant temperatures 30°C and 70°C was measured.Results showed a general decrease in viscosity by increasing the temperature. Moreover, we found that increase in viscosity occurred by increasing of nanoparticles ’concentration.

Keywords