A Phenomenological Model for Soot Formation and Oxidation in Direct-Injection Diesel Engines

952428

10/01/1995

Event
1995 SAE International Fall Fuels and Lubricants Meeting and Exhibition
Authors Abstract
Content
The concentration of carbonaceous particulate matter in the exhaust of diesel engines depends on the rates of formation and oxidation of soot in the combustion chamber. Soot forms early in the combustion process when local fuel-rich areas exist, whereas soot oxidation occurs later when more air is entrained into the fuel spray. Based on this understanding, a phenomenological combustion model is established. In the model, the cylinder volume is divided into four zones: a rich fuel spray core, a premixed-burning/burned gas zone, a mixing controlled burning zone and a lean air zone. Soot formation takes place in the mixing controlled burning zone where the local C/O ratio is above the critical value. Soot oxidation occurs in the premixed-burning/burned gas zone as air is entrained. By using a quasi-global chemical reaction scheme, the oxidation of soot particles by different species can be investigated. The model predictions were compared with the measured cylinder pressure and exhaust emission data. A reasonably good agreement was observed. A number of oxidation rates cited in the literature were tested in this model. It was found that the oxidation rate established by Nagle and Strickland-Constable adequately accounted for the apparent soot oxidation rate under diesel engine conditions.
Meta TagsDetails
DOI
https://doi.org/10.4271/952428
Pages
16
Citation
Li, X., and Wallace, J., "A Phenomenological Model for Soot Formation and Oxidation in Direct-Injection Diesel Engines," SAE Technical Paper 952428, 1995, https://doi.org/10.4271/952428.
Additional Details
Publisher
Published
Oct 1, 1995
Product Code
952428
Content Type
Technical Paper
Language
English