Dissipation Element Analysis of Turbulent Premixed Jet Flames

D. Denker, A. Attili, S. Luca, F. Bisetti, M. Gauding, H. Pitsch

Research output: Contribution to journalArticlepeer-review

Abstract

Dissipation element (DE) analysis is a method for analyzing scalar fields in turbulent flows. DEs are defined as a coherent region in which all gradient trajectories of a scalar field reach the same extremal points. Therefore, the scalar field can be compartmentalized in monotonous space-filling regions.

The DE analysis is applied to a set of spatially evolving premixed jet flames at different Reynolds numbers. The simulations feature finite rate chemistry with 16 species and 73 reactions. The jet consists of a methane/air mixture with an equivalence ratio φ = 0.7.

Statistics of DE parameters are shown and compared to those of a DNS of a non-reacting spatial jet, a non-reacting temporally evolving jet and isotropic homogeneous turbulence.

The invariance of the normalized length distribution of the DEs toward changes in Reynolds number observed in non-reacting flows holds for the reacting cases and the characteristic scaling with Kolmogorov micro-scale is reproduced. Furthermore, the DE statistics reflect the influence of the premixed flame structure on the turbulent scalar fields.
Original languageEnglish
Pages (from-to)1677-1692
Number of pages16
JournalCombustion Science and Technology
Volume191
Issue number9
Early online date21 Apr 2019
DOIs
Publication statusE-pub ahead of print - 21 Apr 2019

Keywords

  • premixed flames
  • turbulent combustion
  • Direct numerical simulation (DNS)
  • isotropic turbulence

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