PRE-INJECTION IN HIGH-SPEED DIRECT-INJECTION PASSENGER-CAR DIESEL ENGINES WITH MIXTURE FORMATION LARGELY EFFECTED BY AIR DISTRIBUTION
VOREINSPRITZUNG BEI SCHNELLAUFENDEN DIREKTEINSPRITZENDEN PKW-DIESELMOTOREN MIT UEBERWIEGEND LUFTVERTEILENDER GEMISCHBILDUNG
The author studied the influence of pre-injection (injection of a small pilot quantity prior to the main injection proper) on the combustion of a small-sized, high-speed direct-injection diesel engine with mixture formation largely effected by air distribution. The process was simulated in a combustion chamber allowing the combustion course to be directly observed and analysed by high-speed schlieren optics. The injection geometry of the pilot injection nozzle was varied for process optimization. The author presents the study results in greater detail relative to considerably shortened ignition delay of the main quantity by pilot injection, maximal cylinder pressure gradients and pressure levels, maximally possible thermal efficiency, incomplete evaporation of the injected fuel quantity during the very short ignition delay. The maximal conversion rate of the main combustion was found to be reduced due to the shortened ignition delay and the inert gas action of the exhaust gases of the pilot combustion. HC emissions and cold-start behavior of the engine were found to be improved by pre-injection.
Technische Hochschule AachenFakultaet fuer Maschinenwesen
- Koenigs, M
- Publication Date: 1988-2-9
- Pagination: 148 p.
- TRT Terms: Cold starts (Driving); Combustion; Combustion chambers; Diesel engines; Exhaust gases; Fuel injection; Ignition; Temperature
- Uncontrolled Terms: Ignition timing
- Old TRIS Terms: Cold start; Direct injection engines; Ignition temperature
- Subject Areas: Highways; Vehicles and Equipment;
- Accession Number: 00615851
- Record Type: Publication
- Source Agency: National Technical Information Service
- Files: TRIS
- Created Date: Sep 30 1991 12:00AM