Browse Publications Technical Papers 2012-01-0882
2012-04-16

Optical Analysis and Measurement of Crankcase Lubricant Oil Atomisation 2012-01-0882

Crankcase emissions are a complex mixture of combustion products and, specifically Particulate Matter (PM) from lubricant oil. Crankcase emissions contribute substantially to the particle mass and particle number (PN) emitted from an internal combustion engine. Environmental legislation demands that the combustion and crankcase emissions are either combined to give a total measurement or the crankcase gases are re-circulated back into the engine, both strategies require particle filtration. There is a lack of understanding regarding the physical processes that generate crankcase emissions of lubricant oil, specifically how the bulk lubricant oil is atomised into droplets.
In this paper the crankcase of a motored compression ignition engine, has been optically accessed to visualise the lubricant oil distribution. The oil distribution was analysed in detail using high speed laser diagnostics, at engine speeds up to 2000 rpm and oil temperatures of 90°C.
High resolution calibrated images show the passive behavior of lubricant oil once it has been supplied to critical engine components. The major mechanisms of oil atomisation have been identified and quantified from high speed images, the generation of oil droplets dp = 10 μm - 3 mm has been captured. The most significant generation mechanism was atomisation of oil films present on the surface of rotating components. The isolated contribution of the crank and camshafts to the atomised oil droplets present in the top of the engine has been recorded. Further breakup, evaporation and condensation from the surface of the atomised oil droplets will generate coarse and fine PM. Results from imaging data show good correlation with sub-micron PN sampling measurements captured in a previous study [1]; namely an increase in particle number concentration with increasing engine speed.

SAE MOBILUS

Subscribers can view annotate, and download all of SAE's content. Learn More »

Access SAE MOBILUS »

Members save up to 18% off list price.
Login to see discount.
Special Offer: Download multiple Technical Papers each year? TechSelect is a cost-effective subscription option to select and download 12-100 full-text Technical Papers per year. Find more information here.
We also recommend:
TECHNICAL PAPER

The Impact of Additive Chemistry and Lubricant Rheology on Wear in Heavy Duty Diesel Engines

1999-01-3575

View Details

TECHNICAL PAPER

Diesel Engine Lube Filter Life Related to Oil Chemistry

780974

View Details

TECHNICAL PAPER

The Effect of Lubricating Oil Additives on Valve Recession in Stationary Gaseous-Fueled Four-Cycle Engines

932780

View Details

X