Abstract:-
This work studies the effect of nanoparticles (NPs) on the flow and physical properties of engine oil. The controlling on the viscosity, flash, fire point and thermal conductivity is essential issue to improve the engine oil lubricant performance. Recently nanoparticles can be used as an additive to the engine oil to improve its properties. The graphite (Gr) and zinc oxide (ZnO) NPs with main diameter of 40 nm were mixed with the 20W50 oil using magnetic stirrer and ultrasonic process. Cone-plate is used to check the dynamic viscosity. SYD3536 flash point apparatus is used to test the flash and fire point, also the effect of ZnO and Gr NPs on the thermal conductivity of nano-oil is tested using KD2 probe instrument. The results indicated that the higher concentration of NPs, the better properties of the base nano-oil, the flash and fire point generally increases with the NPs concentration increasing. The Gr nano-oil generates higher flash and fire point than that of ZnO nano-oil. The dynamic viscosity produces a slight change due to NPs concentration increasing at different temperatures especially at 40?C for both nano-oil. At temperatures over 40?C the viscosity increases with the NPs concentrations increasing, while below 40?C the viscosity decreasing. The thermal conductivity increases with NPs percentage increasing, where the Gr nano-oil the higher value than that of ZnO nano-oil.