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Large Eddy Simulation and Experiments of the Auto-Ignition Process of Lean Ethanol / Air Mixture in HCCI Engines

Joelsson, Tobias LU ; Yu, Rixin LU ; Bai, Xue-Song LU ; Vressner, Andreas LU and Johansson, Bengt LU (2008) In SAE International Journal of Fuels and Lubricants 1(1). p.1110-1119
Abstract
Recent experiments and numerical studies have showed that piston geometry has a significant effect on the homogeneous charge compression ignition (HCCI) process. There are two effects generated by the combustor geometry: the geometry affects the flow/turbulence in the cylinder; the geometry also affects the temperature stratification. The temperature stratification is more directly responsible for the observed alteration of the auto-ignition process. To clarify this issue further we present in this paper a study of two engines with the same geometry but difference ways of cooling. Measurement of the two engines~a metal engine and quartz piston engine, both with the same piston bowl geometry~is carried out. Large eddy simulation (LES) is... (More)
Recent experiments and numerical studies have showed that piston geometry has a significant effect on the homogeneous charge compression ignition (HCCI) process. There are two effects generated by the combustor geometry: the geometry affects the flow/turbulence in the cylinder; the geometry also affects the temperature stratification. The temperature stratification is more directly responsible for the observed alteration of the auto-ignition process. To clarify this issue further we present in this paper a study of two engines with the same geometry but difference ways of cooling. Measurement of the two engines~a metal engine and quartz piston engine, both with the same piston bowl geometry~is carried out. Large eddy simulation (LES) is used to simulate the flow, the temperature field and the auto-ignition process in the two engines. The fuel is ethanol with a relative air/fuel ratio of 3.3. It is found that lower temperature stratification is established in the metal engine under similar conditions as the optical quartz engine due to the more effective cooling of the piston in the metal engine configuration. The combustion phasing in the two engines is the same by controlling the intake temperature. Both measurements and LES show a more rapid auto-ignition in the metal engine than in the optical engine with the same piston geometry. This confirms the conclusion that large temperature stratification can decrease the pressure-rise-rate and thereby increase the load of HCCI engines. The dependence of temperature stratification on the wall temperature and intake temperature is systematically studied using LES. (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
Combustion Engine, HCCI, Large Eddy Simulation
in
SAE International Journal of Fuels and Lubricants
volume
1
issue
1
pages
1110 - 1119
publisher
SAE
external identifiers
  • scopus:84877463593
ISSN
1946-3952
language
English
LU publication?
yes
id
bcb0e437-1563-422f-b3a1-9f205547f0a7 (old id 1396291)
alternative location
http://www.sae.org/technical/papers/2008-01-1668
http://www.sae.org/technical/books/V117-4
date added to LUP
2009-05-13 12:36:42
date last changed
2017-01-01 05:17:30
@article{bcb0e437-1563-422f-b3a1-9f205547f0a7,
  abstract     = {Recent experiments and numerical studies have showed that piston geometry has a significant effect on the homogeneous charge compression ignition (HCCI) process. There are two effects generated by the combustor geometry: the geometry affects the flow/turbulence in the cylinder; the geometry also affects the temperature stratification. The temperature stratification is more directly responsible for the observed alteration of the auto-ignition process. To clarify this issue further we present in this paper a study of two engines with the same geometry but difference ways of cooling. Measurement of the two engines~a metal engine and quartz piston engine, both with the same piston bowl geometry~is carried out. Large eddy simulation (LES) is used to simulate the flow, the temperature field and the auto-ignition process in the two engines. The fuel is ethanol with a relative air/fuel ratio of 3.3. It is found that lower temperature stratification is established in the metal engine under similar conditions as the optical quartz engine due to the more effective cooling of the piston in the metal engine configuration. The combustion phasing in the two engines is the same by controlling the intake temperature. Both measurements and LES show a more rapid auto-ignition in the metal engine than in the optical engine with the same piston geometry. This confirms the conclusion that large temperature stratification can decrease the pressure-rise-rate and thereby increase the load of HCCI engines. The dependence of temperature stratification on the wall temperature and intake temperature is systematically studied using LES.},
  author       = {Joelsson, Tobias and Yu, Rixin and Bai, Xue-Song and Vressner, Andreas and Johansson, Bengt},
  issn         = {1946-3952},
  keyword      = {Combustion Engine,HCCI,Large Eddy Simulation},
  language     = {eng},
  number       = {1},
  pages        = {1110--1119},
  publisher    = {SAE},
  series       = {SAE International Journal of Fuels and Lubricants},
  title        = {Large Eddy Simulation and Experiments of the Auto-Ignition Process of Lean Ethanol / Air Mixture in HCCI Engines},
  volume       = {1},
  year         = {2008},
}