A simulation of the exhaust emission testing system including a vehicle, dynamometer and driver on General Motors' analog-digital hybrid computer is described. The simulation predicts instantaneous and average results for hydrocarbons (HC), carbon monoxide (CO), oxides of nitrogen (NOx), carbon dioxide (CO2), and fuel economy over a predefined speed schedule such as the Environmental Protection Agency's (EPA's) city and highway schedules. Among the potential applications of the simulation are characterization of sensitivity relationships between important parameters of the test system and emission results on tests conducted in the laboratory. Examples include sensitivity to dynamometer characteristics, driver, Driver's Aid and ambient conditions; determination of sensitivity of emissions and fuel economy to performance characteristics of various components of the vehicle which influence them such as engines, axles and transmissions; estimation of the effect of product mix on emissions and fuel economy, and determination of the effect of road load, aerodynamic drag, etc., on fuel economy driving any specified speed schedule. The ability of the model to predict absolute emission levels would be highly dependent upon the quality of performance maps, the extent to which the engine dynamics are simulated and the validity of any underlying assumptions.

  • Supplemental Notes:
    • Preprint for meeting held February 27-March 3, 1978.
  • Corporate Authors:

    Society of Automotive Engineers (SAE)

    400 Commonwealth Drive
    Warrendale, PA  United States  15096
  • Authors:
    • Juneja, W K
    • Kelly, W J
    • Valentine, R W
  • Publication Date: 1978

Media Info

  • Pagination: 20 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00180077
  • Record Type: Publication
  • Source Agency: Engineering Index
  • Report/Paper Numbers: SAE 780287 Preprint
  • Files: TRIS, ATRI
  • Created Date: Oct 12 1978 12:00AM