OFF-STOICHIOMETRY OPERATION OF AN SI ENGINE -- A MODEL OF FORMATION AND CONTROL OF NITRIC OXIDE

The highest concentrations of NO appear in the exhaust of a spark ignition engine when it is operated slightly on the lean side of stoichiometry. A suggested method of control therefore is to run the engine at an off-stoichiometric air/fuel ratio where the nitric oxide emission is low. The oxygen atom concentration in the combustion chamber of an engine can be higher than the equilibrium concentration, particularly in the lean mixture region. Such higher concentrations of (0) can yield higher concentrations of NO. This paper desceibes a model which takes account of this super-concentration of oxygen atoms in the flame front in order to predict NO emission levels. Comparisons are made with measured results and the agreement found to be good. The combustion duration period is considered as a critical parameter in the control of NO in the lean mixture range. /GMRL/

• Corporate Authors:

  Society of Automotive Engineers (SAE)

  400 Commonwealth Drive
  Warrendale, PA  United States  15096
• Authors:
  • LUCAS, G G
  • VARDE, K S
• Publication Date: 1975

Media Info

• Pagination: 9 p.

Subject/Index Terms

• TRT Terms: Combustion; Engines; Forecasting; Fuel air mixtures; Fuels; Mathematical models; Nitric oxide; Oxygen; Pollutants; Spark ignition engines; Stoichiometry; Time
• Uncontrolled Terms: Air fuel ratio
• Subject Areas: Energy; Geotechnology; Highways; Materials; Safety and Human Factors; Vehicles and Equipment;

Filing Info

• Accession Number: 00098903
• Record Type: Publication
• Report/Paper Numbers: SAE #750352
• Files: TRIS
• Created Date: Sep 30 1975 12:00AM