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Direct numerical simulation of PRF70/air partially premixed combustion under IC engine conditions

Zhang, Fan LU ; Yu, Rixin LU and Bai, Xue-Song LU (2015) In Proceedings of the Combustion Institute 35. p.2975-2982
Abstract
A three-dimensional direct numerical simulation (DNS) is performed to study the ignition and the combustion process of a primary reference fuel (PRF) under conditions relevant to partially premixed combustion (PPC) engines. Detailed transport properties together with a skeletal PRF chemical kinetic mechanism are employed in the simulations. The initial partially premixed charge is prescribed according to a two-injection of fuel strategy with a 50% exhaust gas recirculation (EGR). The motion of the piston, hence, the effect of compression of the charge due to the piston motion is considered. The simulations are performed with a fine mesh with a spatial resolution of 1.2 micrometers in a cubic domain of 614 micrometers on each side. The... (More)
A three-dimensional direct numerical simulation (DNS) is performed to study the ignition and the combustion process of a primary reference fuel (PRF) under conditions relevant to partially premixed combustion (PPC) engines. Detailed transport properties together with a skeletal PRF chemical kinetic mechanism are employed in the simulations. The initial partially premixed charge is prescribed according to a two-injection of fuel strategy with a 50% exhaust gas recirculation (EGR). The motion of the piston, hence, the effect of compression of the charge due to the piston motion is considered. The simulations are performed with a fine mesh with a spatial resolution of 1.2 micrometers in a cubic domain of 614 micrometers on each side. The results show that there are three distinctive combustion regions in a domain under PPC conditions, a lean homogeneous mixture region, a fuel-rich region, and in between a region with stoichiometric mixture. Auto-ignition occurs first in the lean and stoichiometric mixture regions, followed by a partially premixed flame in the fuel-rich region and at last a CO oxidation phase in the fuel-rich region. In the lean mixture region, the fuel and the combustion intermediates such as CO are consumed almost completely due to the relatively fast combustion and the abundant oxygen. The CO formed in the regions with the stoichiometric and the fuel-rich mixture is consumed in a mixing controlled mode, which requires a high-level turbulence mixing or a sufficiently long residence time. NO is formed mainly due to the premixed combustion in the region with the stoichiometric mixture. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Direct numerical simulation, Partially premixed combustion, PRF fuel, IC engines
in
Proceedings of the Combustion Institute
volume
35
pages
2975 - 2982
publisher
Elsevier
external identifiers
  • wos:000348049500057
  • scopus:84947543729
ISSN
1540-7489
DOI
10.1016/j.proci.2014.09.004
language
English
LU publication?
yes
id
965adee0-063c-4ab6-9373-930e629850a5 (old id 4022791)
date added to LUP
2013-09-12 13:27:06
date last changed
2017-06-25 03:25:10
@article{965adee0-063c-4ab6-9373-930e629850a5,
  abstract     = {A three-dimensional direct numerical simulation (DNS) is performed to study the ignition and the combustion process of a primary reference fuel (PRF) under conditions relevant to partially premixed combustion (PPC) engines. Detailed transport properties together with a skeletal PRF chemical kinetic mechanism are employed in the simulations. The initial partially premixed charge is prescribed according to a two-injection of fuel strategy with a 50% exhaust gas recirculation (EGR). The motion of the piston, hence, the effect of compression of the charge due to the piston motion is considered. The simulations are performed with a fine mesh with a spatial resolution of 1.2 micrometers in a cubic domain of 614 micrometers on each side. The results show that there are three distinctive combustion regions in a domain under PPC conditions, a lean homogeneous mixture region, a fuel-rich region, and in between a region with stoichiometric mixture. Auto-ignition occurs first in the lean and stoichiometric mixture regions, followed by a partially premixed flame in the fuel-rich region and at last a CO oxidation phase in the fuel-rich region. In the lean mixture region, the fuel and the combustion intermediates such as CO are consumed almost completely due to the relatively fast combustion and the abundant oxygen. The CO formed in the regions with the stoichiometric and the fuel-rich mixture is consumed in a mixing controlled mode, which requires a high-level turbulence mixing or a sufficiently long residence time. NO is formed mainly due to the premixed combustion in the region with the stoichiometric mixture.},
  author       = {Zhang, Fan and Yu, Rixin and Bai, Xue-Song},
  issn         = {1540-7489},
  keyword      = {Direct numerical simulation,Partially premixed combustion,PRF fuel,IC engines},
  language     = {eng},
  pages        = {2975--2982},
  publisher    = {Elsevier},
  series       = {Proceedings of the Combustion Institute},
  title        = {Direct numerical simulation of PRF70/air partially premixed combustion under IC engine conditions},
  url          = {http://dx.doi.org/10.1016/j.proci.2014.09.004},
  volume       = {35},
  year         = {2015},
}