Investigation of Augmented Mixing Effects on Direct-Injection Stratified Combustion Mercury Marine division of Brunswick Corporation

Format:

Conference/Event

Author/Creator:

McGuire, B. A., author.

Conference Name:

SAE International Fall Fuels & Lubricants Meeting & Exhibition (2001-09-24 : San Antonio, Texas, United States)

Spring Fuels & Lubricants Meeting & Exhibition (2002-05-06 : Reno, Nevada, United States)

Language:

English

Physical Description:

1 online resource

Place of Publication:

Warrendale, PA SAE International 2001

Summary:

The effects of augmented mixing through the use of an auxiliary gas injection (AGI) were investigated in a direct-injection gasoline engine operated at a 22:1 overall air-fuel ratio, but with retarded injection timing such that the combustion was occurring in a locally rich mixture as evident by the elevated CO emissions. Two AGI gas compositions, nitrogen and air, were utilized, the gas supply temperature was ambient, and a wide range of AGI timings were investigated. The injected mass was less than 10% of the total chamber mass. The injection of nitrogen during the latter portion of the heat release phase resulted in a 25% reduction in the CO emissions. This reduction is considered to be the result of the increased mixing rate of the rich combustion products with the available excess air during a time when the temperatures are high enough to promote rapid oxidation. This CO reduction was achieved despite the fact that the injected gas had a low temperature and was inert, both attributes should result in reduced oxidation rates. The effect of temperature and composition were observed by a significant reduction in the NOx emissions at the same conditions, confirming that the AGI orientation was effecting changes in the high temperature in-cylinder processes. At the same conditions air AGI (i.e an oxidizing gas) produced a more significant CO reduction, and the oxygen content counteracted the low temperature to cause no change in the NOx emissions. These findings suggest that a lack of late-cycle mixing limits the emissions potential of current direct-injection engines

Notes:

Vendor supplied data

Publisher Number:

2001-01-3670

Access Restriction:

Restricted for use by site license