Effects of Gas Flow and Mixture Properties on Engine-Out HC Emissions

961952

10/01/1996

Event
1996 SAE International Fall Fuels and Lubricants Meeting and Exhibition
Authors Abstract
Content
The geometry and area of the notch in the swirl control valve installed in the intake port were varied to analyze the effects on HC emissions. A swirl control valve functions to promote the formation of a homogeneous mixture, enabling the amount of liquid fuel supplied to the cylinder to be reduced. For this reason, it is difficult to obtain an added effect through the combined use of a swirl control valve and an auxiliary-air type of injector for assisting fuel atomization. Tumble (vertical swirl) flow fields are effective in shortening the combustion period. This results in a higher exhaust gas temperature at an equivalent level of combustion stability. It was thought that swirl flow fields produce residual gas flow in the cylinder after the completion of the main combustion period. It is surmised that the residual gas flow functions to diffuse and promote after-burning of the unburned HC layer. Accordingly, slanted swirl flow fields, having the characteristics and effects of both vertical and horizontal swirl, would be the most effective in reducing HC emissions.
Meta TagsDetails
DOI
https://doi.org/10.4271/961952
Pages
13
Citation
Tomita, M., Iwakiri, Y., Sakai, E., Urushihara, T. et al., "Effects of Gas Flow and Mixture Properties on Engine-Out HC Emissions," SAE Technical Paper 961952, 1996, https://doi.org/10.4271/961952.
Additional Details
Publisher
Published
Oct 1, 1996
Product Code
961952
Content Type
Technical Paper
Language
English