HOMOGENEOUS MIXTURES MAY NOT BE OPTIMAL FOR LEAN COMBUSTION

General Motors researchers studying the effects of mixture preparation on steady-state combustion found an injected fuel/air mixture even better than a prevaporized one in terms of lean limits, combustion pressure variations, and specific fuel consumption. Two possible mechanisms are postulated for how lean operation may be enhanced by less-than-complete vaporization. One is a possible bulk stratification of the charge, and the other involves an optimal droplet size. These results could have far-reaching implications in design of lean-combustion engines. In their investigations, GM researchers fitted fuel injection to a Cooperative Fuel Research engine. Among parameters measured were peak pressure and its variation, ignition delay, combustion rate, specific fuel consumption, emissions, and knock sensitivity. Three others, central to the investigation, are described in more detail ignition limit; partial-burn limit, and lean misfire limit.

Media Info

  • Pagination: p. 66-70
  • Serial:
    • Automotive Engineering
    • Volume: 86
    • Issue Number: 6
    • Publisher: Society of Automotive Engineers (SAE)
    • ISSN: 0098-2571

Subject/Index Terms

Filing Info

  • Accession Number: 00183254
  • Record Type: Publication
  • Source Agency: Engineering Index
  • Files: TRIS
  • Created Date: Dec 12 1978 12:00AM