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

Chartier, Clement LU ; Aronsson, Ulf LU ; Andersson, Öivind LU ; Egnell, Rolf LU ; Collin, Robert LU ; Seyfried, Hans LU ; Richter, Mattias LU and Aldén, Marcus LU (2009) In SAE Technical Paper 2009-01-1353 2009-01-1353.
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... (More)
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. (Less)
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Contribution to specialist publication or newspaper
publication status
published
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categories
Popular Science
in
SAE Technical Paper 2009-01-1353
volume
2009-01-1353
publisher
SAE
external identifiers
  • other:2009-01-1353
  • scopus:84877240016
DOI
10.4271/2009-01-1353
language
English
LU publication?
yes
id
a98e494f-5269-4b31-ad72-e47a58bcddfe (old id 2543762)
date added to LUP
2012-05-23 15:23:43
date last changed
2017-04-16 04:27:19
@misc{a98e494f-5269-4b31-ad72-e47a58bcddfe,
  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.},
  author       = {Chartier, Clement and Aronsson, Ulf and Andersson, Öivind and Egnell, Rolf and Collin, Robert and Seyfried, Hans and Richter, Mattias and Aldén, Marcus},
  language     = {eng},
  publisher    = {SAE},
  series       = {SAE Technical Paper 2009-01-1353},
  title        = {Analysis of Smokeless Spray Combustion in a Heavy-Duty Diesel Engine by Combined Simultaneous Optical Diagnostics},
  url          = {http://dx.doi.org/10.4271/2009-01-1353},
  volume       = {2009-01-1353},
  year         = {2009},
}