IDENTIFYING A CRITICAL TIME FOR MIXING IN A DIRECT INJECTION DIESEL ENGINE THROUGH THE STUDY OF INCREASED IN-CYLINDER MIXING AND ITS EFFECT ON EMISSIONS

An experimental study aimed at understanding the effect of in-cylinder mixing on direct injection diesel combustion was conducted in which an auxiliary gas injector was installed on to a single-cylinder diesel engine. The gas injector was used to inject air and nitrogen, thereby enhancing in-cylinder mixing at a specific time in the combustion cycle. The phasing of that gas injection event with respect to the fuel injection event was changed. The results suggest that it is primarily the fuel injected at the tail end of the fuel injection event that has difficulty mixing. Prior to the end of fuel injection, the kinetic energy input during fuel injection is sufficient to mix the fuel with air. However, near the end of fuel injection the kinetic energy is low and the fuel is not followed by any kinetic energy inputs that could help bring about mixing, which causes that fuel to produce large amounts of soot that ultimately have trouble oxidizing. It was also found that in-cylinder turbulence had no effect on NOx emissions when it occurred after +20 degrees ATDC (after top dead centre), just after the end of fuel injection in these experiments. It was believed that, by that time, the NOx chemistry was frozen. However, NOx emissions were affected by early gas injection such that injecting air brought about an increase in NOx emissions while injecting nitrogen reduced NOx emissions. This finding suggests that early and prolonged injection of diluents could be used as a soot-friendly form of exhaust gas recirculation, provided that the injection overlaps the end of fuel injection. (A)

• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/issn/14680874
• Corporate Authors:

  PROFESSIONAL ENGINEERING PUBLICATIONS LTD

  NORTHGATE AVENUE
  BURY ST EDMUNDS, SUFFOLK  United Kingdom  IP32 6BW
• Authors:
  • KURTZ, E M
  • FOSTER, D E
• Publication Date: 2004

Language

• English

Media Info

• Features: References;
• Pagination: p. 247-56
• Serial:
  • International Journal of Engine Research
  • Volume: 5
  • Issue Number: 3
  • Publisher: Sage Publications, Incorporated
  • ISSN: 1468-0874
  • EISSN: 20413149

Subject/Index Terms

• TRT Terms: Air; Diesel engines; Energy; Fuel injection; Nitrogen; Pollutants; Vehicles
• ITRD Terms: 6714: Air; 1314: Diesel engine; 2442: Emission; 213: Energy; 3830: Injection (fuel); 7128: Nitrogen; 1255: Vehicle
• Subject Areas: Energy; Vehicles and Equipment;

Filing Info

• Accession Number: 00976838
• Record Type: Publication
• Source Agency: Transport Research Laboratory
• Files: ITRD
• Created Date: Aug 4 2004 12:00AM