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Large eddy simulation of n-Dodecane spray combustion in a high pressure combustion vessel

Gong, Cheng LU ; Jangi, Mehdi LU and Bai, Xue-Song LU (2014) In Applied Energy 136. p.373-381
Abstract
Autoignition and stabilization of n-Dodecane spray combustion under diesel engine like conditions are investigated using large eddy simulation and detailed chemical kinetics. The Spray A cases of Engine Combustion Network (ECN) with ambient temperatures of 900 K and 1000 K are considered. Two-stage ignition behavior is predicted in the studied conditions. It is found that the first-stage ignition occurs on the fuel-lean mixture, whereas the second-stage ignition starts on the fuel-rich mixture. The first stage ignition in the fuel-lean mixture promotes the first and the second stage ignition in the fuel-rich mixture owing to rapid turbulent mixing. Two mechanisms, autoignition and flame propagation coupling with the low temperature... (More)
Autoignition and stabilization of n-Dodecane spray combustion under diesel engine like conditions are investigated using large eddy simulation and detailed chemical kinetics. The Spray A cases of Engine Combustion Network (ECN) with ambient temperatures of 900 K and 1000 K are considered. Two-stage ignition behavior is predicted in the studied conditions. It is found that the first-stage ignition occurs on the fuel-lean mixture, whereas the second-stage ignition starts on the fuel-rich mixture. The first stage ignition in the fuel-lean mixture promotes the first and the second stage ignition in the fuel-rich mixture owing to rapid turbulent mixing. Two mechanisms, autoignition and flame propagation coupling with the low temperature ignition, are used to explain the lift-off position and stabilization of the combustion process. They compete with each other, and their relative importance depends on the ambient temperature. The ambient temperature is shown to affect the soot emission in the flame through its influences on the lift-off length and the reaction zone structure. Higher ambient temperature results in a shorter lift-off length, which gives rise to higher soot emission due to the lower air entrainment to the fuel-rich zone in front of the flame. In the lower temperature case, the flame is stabilized by an autoignition induced flame front where a considerable amount of fuel is oxidized to CO at the leading front of the flame. Consequently, it reduces the soot formation in the flame. (C) 2014 Elsevier Ltd. All rights reserved. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Diesel combustion, Autoignition, Flame stabilization, Large eddy, simulation
in
Applied Energy
volume
136
pages
373 - 381
publisher
Elsevier
external identifiers
  • wos:000345725800037
  • scopus:84930941813
ISSN
1872-9118
DOI
10.1016/j.apenergy.2014.09.030
language
English
LU publication?
yes
id
2345cbdb-272d-4787-93f2-1530398a2586 (old id 4962600)
date added to LUP
2015-01-29 11:52:24
date last changed
2017-07-23 04:05:52
@article{2345cbdb-272d-4787-93f2-1530398a2586,
  abstract     = {Autoignition and stabilization of n-Dodecane spray combustion under diesel engine like conditions are investigated using large eddy simulation and detailed chemical kinetics. The Spray A cases of Engine Combustion Network (ECN) with ambient temperatures of 900 K and 1000 K are considered. Two-stage ignition behavior is predicted in the studied conditions. It is found that the first-stage ignition occurs on the fuel-lean mixture, whereas the second-stage ignition starts on the fuel-rich mixture. The first stage ignition in the fuel-lean mixture promotes the first and the second stage ignition in the fuel-rich mixture owing to rapid turbulent mixing. Two mechanisms, autoignition and flame propagation coupling with the low temperature ignition, are used to explain the lift-off position and stabilization of the combustion process. They compete with each other, and their relative importance depends on the ambient temperature. The ambient temperature is shown to affect the soot emission in the flame through its influences on the lift-off length and the reaction zone structure. Higher ambient temperature results in a shorter lift-off length, which gives rise to higher soot emission due to the lower air entrainment to the fuel-rich zone in front of the flame. In the lower temperature case, the flame is stabilized by an autoignition induced flame front where a considerable amount of fuel is oxidized to CO at the leading front of the flame. Consequently, it reduces the soot formation in the flame. (C) 2014 Elsevier Ltd. All rights reserved.},
  author       = {Gong, Cheng and Jangi, Mehdi and Bai, Xue-Song},
  issn         = {1872-9118},
  keyword      = {Diesel combustion,Autoignition,Flame stabilization,Large eddy,simulation},
  language     = {eng},
  pages        = {373--381},
  publisher    = {Elsevier},
  series       = {Applied Energy},
  title        = {Large eddy simulation of n-Dodecane spray combustion in a high pressure combustion vessel},
  url          = {http://dx.doi.org/10.1016/j.apenergy.2014.09.030},
  volume       = {136},
  year         = {2014},
}