Browse Publications Technical Papers 2007-01-4014
2007-10-29

Initial Estimation of the Piston Ring Pack Contribution to Hydrocarbon Emissions from a Small Engine 2007-01-4014

The contribution to the engine-out hydrocarbon (HC) emissions from fuel that escapes the main combustion event in piston ring crevices was estimated for an air-cooled, V-twin utility engine. The engine was run with a homogeneous pre-vaporized mixture system that avoids the presence of liquid films in the cylinder, and their resulting contribution to the HC emissions. A simplified ring pack gas flow model was used to estimate the ring pack contribution to HC emissions; the model was tested against the experimentally measured blowby. At high load conditions the model shows that the ring pack returns to the cylinder a mass of HC that exceeds that observed in the exhaust, and thus, is the dominant contributor to HC emissions. At light loads, however, the model predicts less HC mass returned from the ring pack than is observed in the exhaust. Time-resolved HC measurements were performed and used to assess the effect of combustion quality on HC emissions. It was shown that the both the HC concentration and the HC mass emitted per cycle, from a single-cycle gas flow model, correlated with low IMEP and late combustion phasing. A statistical analysis showed that the correlation was significant. Thus, at light load incomplete combustion was found to be a significant contributor to engine-out emissions.

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:
JOURNAL ARTICLE

Optical Diagnostics and Multi-Dimensional Modeling of Spray Targeting Effects in Late-Injection Low-Temperature Diesel Combustion

2009-01-2699

View Details

JOURNAL ARTICLE

UHC and CO Emissions Sources from a Light-Duty Diesel Engine Undergoing Dilution-Controlled Low-Temperature Combustion

2009-24-0043

View Details

TECHNICAL PAPER

Swirl and Injection Pressure Impact on After-Oxidation in Diesel Combustion, Examined with Simultaneous Combustion Image Velocimetry and Two Colour Optical Method

2013-01-0913

View Details

X