Analysis of Smokeless Spray Combustion in a Heavy-Duty Diesel Engine by Combined Simultaneous Optical Diagnostics

Paper #:
  • 2009-01-1353

Published:
  • 2009-04-20
DOI:
  • 10.4271/2009-01-1353
Citation:
Chartier, C., Aronsson, U., Andersson, Ö., Egnell, R. et al., "Analysis of Smokeless Spray Combustion in a Heavy-Duty Diesel Engine by Combined Simultaneous Optical Diagnostics," SAE Technical Paper 2009-01-1353, 2009, doi:10.4271/2009-01-1353.
Pages:
13
Abstract:
A heavy duty diesel engine operating case producing no engine-out smoke was studied using combined simultaneous optical diagnostics. The case was close to a typical low load modern diesel operating point without EGR. Parallels were drawn to the conceptual model by Dec and results from high-pressure combustion vessels. Optical results revealed that no soot was present in the upstream part of the jet cross-section. Soot was only observed in the recirculation zones close to the bowl perimeter. This indicated very slow soot formation and was explained by a significantly higher air entrainment rate than in Dec's study. The local fuel-air equivalence ratio, Φ, at the lift-off length was estimated to be 40% of the value in Dec's study. The lower Φ in the jet produced a different Φ -T-history, explaining the soot results. The increased air entrainment rate was mainly due to smaller nozzle holes and increased TDC density. Furthermore, increased injection pressure was believed to reduce the residence time in the jet, thus reducing the soot formation. OH was detected at the periphery of the jet, upstream of the location where fuel started to react on the jet centerline. The OH region extended relatively far into the jet, further supporting the conclusion of a less fuel-rich jet in the current case. Partially oxidized fuel (POF) was found at the center of the jet, downstream of the lift-off position. This indicated that the temperature needed to start chemical reactions inside the jet had not been obtained at the lift-off position. The high-temperature reaction zone at the periphery thus added heat over a distance before POF was observed on the centerline.
Access
Now
SAE MOBILUS Subscriber? You may already have access.
Buy
Select
Price
List
Download
$26.00
Mail
$26.00
Members save up to 38% off list price.
Share
HTML for Linking to Page
Page URL

Related Items

Training / Education
2016-10-05
Training / Education
2009-01-22
Article
2015-10-06
Article
2015-09-29
Training / Education
2016-09-29
Technical Paper / Journal Article
2004-11-16
Training / Education
2009-12-15
Technical Paper / Journal Article
2003-10-27
Training / Education
2003-01-22