Heat Release in the End-Gas Prior to Knock in Lean, Rich and Stoichiometric Mixtures With and Without Egr
Författare
Summary, in English
SI Engine knock is caused by autoignition in the unburnt part of the mixture (end-gas) ahead of the propagating flame. Autoignition of the end-gas occurs when the temperature and pressure exceeds a critical limit when comparatively slow reactions - releasing moderate amounts of heat - transform into ignition and rapid heat release.
In this paper the difference in the heat released in the end-gas - by low temperature chemistry - between lean, rich, stochiometric, and stoichiometric mixtures diluted with cooled EGR was examined by measuring the temperature in the end-gas with Dual Broadband Rotational CARS. The measured temperature history was compared with an isentropic temperature calculated from the cylinder pressure trace. The experimentally obtained values for knock onset were compared with results from a two-zone thermodynamic model including detailed chemistry modelling of the end-gas reactions.
In this paper the difference in the heat released in the end-gas - by low temperature chemistry - between lean, rich, stochiometric, and stoichiometric mixtures diluted with cooled EGR was examined by measuring the temperature in the end-gas with Dual Broadband Rotational CARS. The measured temperature history was compared with an isentropic temperature calculated from the cylinder pressure trace. The experimentally obtained values for knock onset were compared with results from a two-zone thermodynamic model including detailed chemistry modelling of the end-gas reactions.
Avdelning/ar
Publiceringsår
2002
Språk
Engelska
Publikation/Tidskrift/Serie
SAE Technical Papers
Länkar
Dokumenttyp
Artikel i tidskrift
Förlag
Society of Automotive Engineers
Ämne
- Energy Engineering
- Atom and Molecular Physics and Optics
Nyckelord
- Combustion Engines
Status
Published
ISBN/ISSN/Övrigt
- ISSN: 0148-7191