When diesel engines are running cold at low loads and speeds (e.g., following winter-weather startup), they produce an objectionable noise termed cold knock. Engineers at Volkswagen have found that high rates of exhaust gas recirculation (EGR) can reduce this cold knock by causing a flattening of the combustion pressure gradient. EGR rates required to produce this effect vary between 25% and 60% of the intake gas quantity. These high rates are only feasible because diesel engines run at very high equivalence ratios when idling.

Media Info

  • Pagination: p. 66-72
  • Serial:
    • Automotive Engineering
    • Volume: 87
    • Issue Number: 9
    • Publisher: Society of Automotive Engineers (SAE)
    • ISSN: 0098-2571

Subject/Index Terms

Filing Info

  • Accession Number: 00325056
  • Record Type: Publication
  • Source Agency: Engineering Index
  • Files: TRIS
  • Created Date: May 21 1981 12:00AM