Impact of Lubricating Oil on Morphology of Particles from a Diesel Engine

AbstractThis study focuses on the impact of lubricating oil on morphology of diesel particles by experimental works. A four cylinder diesel engine was used for generating particles. Neat diesel and oil-dosed fuel were burned, and samples were collected by thermophretic sampling system. Samples were analyzed by transmission electron microscopy (TEM) technique, and size distributions of primary particles, fractal dimension information of aggregates, and aggregate size were studied. Results show that oil-related primary particles are larger than fuel related under low engine load, while the influence of oil is subtle under high load condition. Lubricating oil influences the fractal geometry differently depends on load conditions. Loose structure was observed under low load, however, more compact one appeared under high load. Statistical results indicate that aggregates from oil-dosed fuel have larger gyration diameter compare with neat diesel aggregates, which may be caused by the organic fractions in oil-related particles. Overall, the various combustion ratio under different conditions is responsible for the influence of oil on particle morphology