Analysis of the effect of geometry generated turbulence on HCCI combustion by multi-zone modeling

Salvador M. Aceves*, Daniel L. Flowers, Joel Martinez-Frias, Francisco Espinosa-Loza, Magnus Christensen, Bengt Johansson, Randy P. Hessel

*Corresponding author for this work

Research output: Contribution to conferencePaperpeer-review

24 Scopus citations

Abstract

This paper illustrates the applicability of a sequential fluid mechanics, multi-zone chemical kinetics model to analyze HCCI experimental data for two combustion chamber geometries with different levels of turbulence: a low turbulence disc geometry (flat top piston), and a high turbulence square geometry (piston with a square bowl). The model uses a fluid mechanics code to determine temperature histories in the engine as a function of crank angle. These temperature histories are then fed into a chemical kinetic solver, which determines combustion characteristics for a relatively small number of zones (40). The model makes the assumption that there is no direct linking between turbulence and combustion. The multi-zone model yields good results for both the disc and the square geometries. The model makes good predictions of pressure traces and heat release rates. The experimental results indicate that the high turbulence square geometry has longer burn duration than the low turbulence disc geometry. This difference can be explained by the sequential multi-zone model, which indicates that the cylinder with the square bowl has a thicker boundary layer that results in a broader temperature distribution. This broader temperature distribution tends to lengthen the combustion, as cold mass within the cylinder takes longer to reach ignition temperature when compressed by the expansion of the first burned gases. The multi-zone model, which makes the basic assumption that HCCI combustion is controlled by chemical kinetics, is therefore capable of explaining the experimental results obtained for different levels of turbulence, without considering a direct interaction between turbulence and combustion. A direct connection between turbulence and HCCI combustion may still exist, but it seems to play a relatively minor role in determining burn duration at the conditions analyzed in this paper.

Original languageEnglish (US)
DOIs
StatePublished - Dec 1 2005
Event2005 SAE Brasil Fuels and Lubricants Meeting, SFL 2005 - Rio de Janiero, Brazil
Duration: May 11 2005May 11 2005

Other

Other2005 SAE Brasil Fuels and Lubricants Meeting, SFL 2005
CountryBrazil
CityRio de Janiero
Period05/11/0505/11/05

ASJC Scopus subject areas

  • Automotive Engineering
  • Safety, Risk, Reliability and Quality
  • Pollution
  • Industrial and Manufacturing Engineering

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