1996-05-01

Three-Dimensional Computation of the Effects of the Swirl Ratio in Direct-Injection Diesel Engines on NOx and Soot Emissions 961125

Three-dimensional computation has been applied to analyze combustion and emission characteristics in direct-injection diesel engines. A computational code called TurboKIVA was used to investigate the effects of the swirl ratio, one of the fundamental factors related to combustion control, on combustion characteristics and NOx and soot emissions. The code was first modified to calculate soot formation and oxidation and the precise behavior of fuel drops on the combustion chamber wall. As a result of improving calculation accuracy, good agreement was obtained between the measured and predicted pressure, heat release rate and NOx and soot emissions. Using this modified version of TurboKIVA, the effects of the swirl ratio on NOx and soot emissions were investigated. The computational results showed that soot emissions were reduced with a higher swirl ratio. However, a further increase in the swirl ratio produced greater soot emissions. A careful examination of the fuel spray formation and air-fuel mixing process revealed the reasons for the increased soot emissions. Based on these results, this paper describes the effects of the swirl ratio on combustion characteristics and NOx and soot emissions and the mechanism of soot formation and oxidation in DI diesel engines.

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

Injection Strategy Optimization for a Light Duty DI Diesel Engine in Medium Load Conditions with High EGR rates

2009-01-1441

View Details

TECHNICAL PAPER

Swirl Effects on Mixing and Flame Evolution in a Research DI Diesel Engine

902076

View Details

TECHNICAL PAPER

A Self-Tuning Automotive Cruise Control System Using the Time Delay Controller

920159

View Details

X