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Mixing in wall-jets in a heavy-duty diesel engine : A les study

Solsjö, Rickard LU ; Jangi, Mehdi LU ; Chartier, Clément LU ; Andersson, Öivind LU and Bai, Xue Song LU (2014) SAE 2014 World Congress and Exhibition In SAE Technical Papers 1.
Abstract

The paper presents a large eddy simulation investigation on the effect of fuel injection pressure on mixing, in an optical heavy-duty diesel engine. Recent investigation on impinging wall jets at constant-volume and quiescent conditions exhibited augmented air entrainment in wall jets with increasing injection pressure, when compared with a free jet. The increased mixing rates were explained as owing to enhanced turbulence and vortex formation in the jet-tip in the recirculation zone. A recent investigation carried out in an optical heavy-duty diesel engine indicated however a negligible effect of injection pressure on the mixing in the engine environment. The effect of enhanced turbulence and vortex formation of the jet-tip in the... (More)

The paper presents a large eddy simulation investigation on the effect of fuel injection pressure on mixing, in an optical heavy-duty diesel engine. Recent investigation on impinging wall jets at constant-volume and quiescent conditions exhibited augmented air entrainment in wall jets with increasing injection pressure, when compared with a free jet. The increased mixing rates were explained as owing to enhanced turbulence and vortex formation in the jet-tip in the recirculation zone. A recent investigation carried out in an optical heavy-duty diesel engine indicated however a negligible effect of injection pressure on the mixing in the engine environment. The effect of enhanced turbulence and vortex formation of the jet-tip in the recirculation zone is believed weaker than the effect of engine confinement, due to the presence of fuel from adjacent jets limiting the mixing the fuel with the ambient gas. The aims of this paper are to investigate this issue and to look into more details about the nature of the mixing process in diesel engines. Two fuel injection pressures, 2000 bar and 2500 bar for a constant swirl level of 0.5 and inter-jet angles 45° and 135° were employed. The simulations were performed using OpenFoam, accounting for the mesh-motion and fuel spray treatment. The results exhibit the same trend found in the optical experiments. It was shown that increasing the mass flow rate by increasing injection velocity resulted in augmented turbulence levels in the recirculation zone; however, nearly injection pressure independent equivalence ratio was exhibited during quasi-stationary flow conditions. Copyright © 2014 SAE International.

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author
organization
publishing date
type
Chapter in Book/Report/Conference proceeding
publication status
published
subject
in
SAE Technical Papers
volume
1
publisher
SAE International
conference name
SAE 2014 World Congress and Exhibition
external identifiers
  • Scopus:84899503377
DOI
10.4271/2014-01-1127
language
English
LU publication?
yes
id
c09c17a3-a21e-4c02-bdf7-41bb2568cdf9
date added to LUP
2016-04-08 08:43:21
date last changed
2016-07-14 11:02:30
@misc{c09c17a3-a21e-4c02-bdf7-41bb2568cdf9,
  abstract     = {<p>The paper presents a large eddy simulation investigation on the effect of fuel injection pressure on mixing, in an optical heavy-duty diesel engine. Recent investigation on impinging wall jets at constant-volume and quiescent conditions exhibited augmented air entrainment in wall jets with increasing injection pressure, when compared with a free jet. The increased mixing rates were explained as owing to enhanced turbulence and vortex formation in the jet-tip in the recirculation zone. A recent investigation carried out in an optical heavy-duty diesel engine indicated however a negligible effect of injection pressure on the mixing in the engine environment. The effect of enhanced turbulence and vortex formation of the jet-tip in the recirculation zone is believed weaker than the effect of engine confinement, due to the presence of fuel from adjacent jets limiting the mixing the fuel with the ambient gas. The aims of this paper are to investigate this issue and to look into more details about the nature of the mixing process in diesel engines. Two fuel injection pressures, 2000 bar and 2500 bar for a constant swirl level of 0.5 and inter-jet angles 45° and 135° were employed. The simulations were performed using OpenFoam, accounting for the mesh-motion and fuel spray treatment. The results exhibit the same trend found in the optical experiments. It was shown that increasing the mass flow rate by increasing injection velocity resulted in augmented turbulence levels in the recirculation zone; however, nearly injection pressure independent equivalence ratio was exhibited during quasi-stationary flow conditions. Copyright © 2014 SAE International.</p>},
  author       = {Solsjö, Rickard and Jangi, Mehdi and Chartier, Clément and Andersson, Öivind and Bai, Xue Song},
  language     = {eng},
  publisher    = {ARRAY(0x8887468)},
  series       = {SAE Technical Papers},
  title        = {Mixing in wall-jets in a heavy-duty diesel engine : A les study},
  url          = {http://dx.doi.org/10.4271/2014-01-1127},
  volume       = {1},
  year         = {2014},
}