Browse Publications Technical Papers 1999-01-0505
1999-03-01

Characteristics of Mixture Formation in a Direct Injection SI Engine with Optimized In-Cylinder Swirl Air Motion 1999-01-0505

This paper presents a study of mixture formation in the combustion chamber of a direct-injection SI engine. In-cylinder flow measurement was conducted using laser Doppler velocimetry (LDV) and particle image velocimetry (PIV), and visualization of fuel vapor behavior was done using laser-induced fluorescence (LIF). Further, fast response flame ionization detector (FID) was used to measure the hydrocarbon (HC) concentrations in the vicinity of the spark plug. Thereby mixture concentrations in the vicinity of the spark plug, within the mixture distribution observed using LIF, were quantified. Results revealed that an upward flow forms near the center of the cylinder in the latter half of the compression stroke and goes from the piston crown toward the cylinder head. This upward flow is caused by the synergistic effect of the swirl motion generated in the cylinder and the cylindrical bowl provided in the piston crown eccentrically to the central axis of the cylinder. It was confirmed that the fuel was initially trapped and vaporized in the piston bowl, then transported as a vapor cloud by the upward flow to the spark plug, thereby forming charge stratification. Performance experiments were conducted to study the ranges of fuel injection and ignition timing necessary for achieving stable stratified charge combustion. Comparisons of the data obtained with LIF visualization results and FID measurements revealed the conditions most desirable for achieving stable stratified charge combustion.

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

Effects of Swirl and Tumble on Mixture Preparation During Cold Start of a Gasoline Direct-Injection Engine

2000-01-1900

View Details

TECHNICAL PAPER

Analyses of Cycle-to-Cycle Variation of Combustion and In-Cylinder Flow in a Port Injection Gasoline Engine Using PIV and PLIF Techniques

2017-01-2213

View Details

JOURNAL ARTICLE

High-Speed Flow and Combustion Visualization to Study the Effects of Charge Motion Control on Fuel Spray Development and Combustion Inside a Direct-Injection Spark-Ignition Engine

2011-01-1213

View Details

X