Impact of engine oil volatility and viscosity on blow-by aerosol formation

Abstract Particulate emissions from diesel engines are a matter of public concern and continued industrial development. For an internal combustion engine, particles may originate either the after treatment box or crankcase ventilation system. This paper quantifies discusses particle sources within system medium-duty 4-cylinder heavy-duty 6-cylinder engine their dependence on oil parameters viscosity (expressed as Noack number) HTHS volatility. Crankcase aerosol spectra were measured by optical counter in size range 0.3–5 µm. few cases data filter samples downstream separator unit discussed for total blow-by aerosol. Engines found to behave very similarly with regard changes parameter, volatility generally being far stronger factor influence. Total mass concentration increased up 5 rise about 13–25%. The also increases A variation 3.5 2.6 mPas generated marginal change output 1.2. However, unexpectedly, most viscose relatively highest concentrations both engines.