PARAMETRIC SIMULATION OF SIGNIFICANT DESIGN AND OPERATING ALTERNATIVES AFFECTING THE FUEL ECONOMY AND EMISSIONS OF SPARK-IGNITED ENGINES

A fundamental thermodynamic model of the complete spark-ignited, homogeneous charge engine cycle has been used in several parametric analyses to predict the effects of engine design and operating alternatives on fuel consumption and emissions of NOx and unburned hydrocarbons (HC). The simulation includes sub-models for wall heat transfer, NOx and HC emissions, and the engine breathing processes. This work demonstrates the power and utility of a comprehensive engine simulation by presenting several independent parametric studies that were carried out in response to genuine engine design and/or operating strategy questions. Included in this compilation are the effects of cycle heat loss, exhaust port heat loss, combustion duration, and charge dilution (exhaust gas recirculation and/or lean air-fuel ratio). In addition, the influence of the design variables associated with bore-stroke ratio, intake and exhaust valve lift, and cam timing are considered. Actual engine data is shown to enhance and lend validity to the analytical results when appropriate.

  • Supplemental Notes:
    • Preprint from the 13-16 November 1978 Meeting.
  • Corporate Authors:

    Society of Automotive Engineers (SAE)

    400 Commonwealth Drive
    Warrendale, PA  United States  15096
  • Authors:
    • Novak, J M
    • Blumberg, P N
  • Publication Date: 1978

Media Info

Subject/Index Terms

Filing Info

  • Accession Number: 00195317
  • Record Type: Publication
  • Source Agency: Engineering Index
  • Report/Paper Numbers: SAE 780943
  • Files: TRIS
  • Created Date: Sep 29 1979 12:00AM