LEAN MIXTURE RUNNING OF THE SPARK IGNITION ENGINE BY THE GENERATION OF A VORTEX SYSTEM WITHIN THE INTAKE

Weak (lean) mixture running of automotive spark ignition engines is the means of reducing exhaust emissions and of gaining a small improvement in fuel economy. In order that this may be achieved with acceptable "driveability" the speed of the flame must be increased to a value similar to that existing near that of the stoichiometric mixture strength. Tests on a single-cylinder engine have shown that the flame speed and lean extinction limit may be increased by the fitment of a "vortex generator" in the engine intake. This consists of a nest of delta wings which generates a vortex system in the inlet air flow. The results show that this vortex generator should be of variable geometry and replace the conventional throttle. The main instrumentation on the engine consists of a flame logger which accepts amplified signals from ionization probes set in the engine combustion chamber. The logger is gated to count those flames which travel across the combustion chamber during a set crank angle period. Information from this instrumentation is presented in the form of graphs describing the effect of vortex generator blockage ratio, mixture strength, engine speed, load and spark timing upon the percentage number of flames which cross the chamber and apparent flame speed.

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

    Society of Automotive Engineers

    400 Commonwealth Drive
    Warrendale, PA  USA  15096
  • Authors:
    • LUCAS, G G
    • Petrovic, S
    • Brunt, M
  • Publication Date: 1978

Media Info

Subject/Index Terms

Filing Info

  • Accession Number: 00195307
  • Record Type: Publication
  • Source Agency: Engineering Index
  • Report/Paper Numbers: SAE 780964
  • Files: TRIS
  • Created Date: Sep 29 1979 12:00AM