A study of the influence of exhaust gas recirculation and stoichiometry on the heat release in the end-gas prior to knock using rotational coherent anti-Stokes-Raman spectroscopy thermometry
Grandin, Börje ; Denbratt, Ingemar ; Bood, Joakim LU ; Brackmann, Christian LU and Bengtsson, Per-Erik LU
(2002)
In International Journal of Engine Research
3(4).
p.209-221
- Abstract
- Heat release in the end-gas prior to autoignition was investigated using different experimental methods including transducers for heat flux and pressure as well as rotational coherent anti-Stokes-Raman spectroscopy, which is a laser-based method for non-intrusive instantaneous thermometry of the gas. The time history was examined in the cases of mixtures of various stoichio-metries, where some were diluted with exhaust gas recir-culation (EGR). The measured temperature history was compared with the isentropic temperature calculated from the cylinder pressure trace. This comparison revealed a difference in heat release from low-temperature reactions in the end-gas for the various mixtures tested at a constant indicated mean effective... (More)
- Heat release in the end-gas prior to autoignition was investigated using different experimental methods including transducers for heat flux and pressure as well as rotational coherent anti-Stokes-Raman spectroscopy, which is a laser-based method for non-intrusive instantaneous thermometry of the gas. The time history was examined in the cases of mixtures of various stoichio-metries, where some were diluted with exhaust gas recir-culation (EGR). The measured temperature history was compared with the isentropic temperature calculated from the cylinder pressure trace. This comparison revealed a difference in heat release from low-temperature reactions in the end-gas for the various mixtures tested at a constant indicated mean effective pressure and a fixed position of 50 per cent burnt charge. It is shown that lean mixtures tend to exhibit the highest knock intensity, mainly due to a decrease in specific heat, as compared to the richer mixtures, which result in an earlier knock onset and as a consequence higher knock intensity. Furthermore, the comparison of temperatures indicates that the rich mixtures have a high heat release from low-temperature chemistry, which to some extent negates the higher specific heat of the charge. As a consequence, a slight enrichment of the charge can lead to higher knock intensity in comparison with a stoichiometric mixture. In spite of the lower specific heat of the charge when a stoichiometric charge was diluted with cooled EGR, these mixtures showed a very low tendency to knock. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/744630
- author
- Grandin, Börje
; Denbratt, Ingemar
; Bood, Joakim
LU
; Brackmann, Christian
LU
and Bengtsson, Per-Erik
LU
- organization
- publishing date
- 2002
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- laser diagnosticscombustionCoherent anti-stokes raman spectroscopyCARSHeat releaseautoignitionknock
- in
- International Journal of Engine Research
- volume
- 3
- issue
- 4
- pages
- 209 - 221
- publisher
- Professional Engineering Publishing
- external identifiers
-
- scopus:84990317211
- ISSN
- 1468-0874
- DOI
- 10.1243/146808702762230914
- language
- English
- LU publication?
- yes
- id
- 195d1592-e6ce-4fe4-bd9a-a445f4661b3f (old id 744630)
- date added to LUP
- 2016-04-04 13:43:35
- date last changed
- 2022-04-03 18:42:27
@article{195d1592-e6ce-4fe4-bd9a-a445f4661b3f,
abstract = {{Heat release in the end-gas prior to autoignition was investigated using different experimental methods including transducers for heat flux and pressure as well as rotational coherent anti-Stokes-Raman spectroscopy, which is a laser-based method for non-intrusive instantaneous thermometry of the gas. The time history was examined in the cases of mixtures of various stoichio-metries, where some were diluted with exhaust gas recir-culation (EGR). The measured temperature history was compared with the isentropic temperature calculated from the cylinder pressure trace. This comparison revealed a difference in heat release from low-temperature reactions in the end-gas for the various mixtures tested at a constant indicated mean effective pressure and a fixed position of 50 per cent burnt charge. It is shown that lean mixtures tend to exhibit the highest knock intensity, mainly due to a decrease in specific heat, as compared to the richer mixtures, which result in an earlier knock onset and as a consequence higher knock intensity. Furthermore, the comparison of temperatures indicates that the rich mixtures have a high heat release from low-temperature chemistry, which to some extent negates the higher specific heat of the charge. As a consequence, a slight enrichment of the charge can lead to higher knock intensity in comparison with a stoichiometric mixture. In spite of the lower specific heat of the charge when a stoichiometric charge was diluted with cooled EGR, these mixtures showed a very low tendency to knock.}},
author = {{Grandin, Börje and Denbratt, Ingemar and Bood, Joakim and Brackmann, Christian and Bengtsson, Per-Erik}},
issn = {{1468-0874}},
keywords = {{laser diagnosticscombustionCoherent anti-stokes raman spectroscopyCARSHeat releaseautoignitionknock}},
language = {{eng}},
number = {{4}},
pages = {{209--221}},
publisher = {{Professional Engineering Publishing}},
series = {{International Journal of Engine Research}},
title = {{A study of the influence of exhaust gas recirculation and stoichiometry on the heat release in the end-gas prior to knock using rotational coherent anti-Stokes-Raman spectroscopy thermometry}},
url = {{http://dx.doi.org/10.1243/146808702762230914}},
doi = {{10.1243/146808702762230914}},
volume = {{3}},
year = {{2002}},
}