Decomposition of mixing layer turbulence into coherent structures and background fluctuations

Jacques Lewalle, Joel Delville, Jean Paul Bonnet

Research output: Contribution to journalArticlepeer-review

30 Scopus citations


The eduction of coherent structures from cross-wire rake data in a fully turbulent incompressible mixing layer confirms the feasibility of a decomposition of a turbulent flow field, first suggested by Farge, as non-periodic non-equilibrium coherent structures interacting with a `thermalized' broad-band turbulence. A simple wavelet coefficient decimation algorithm and orthogonalization yields non-periodic dominant flow structures and a background field that has a Gaussian distribution of velocities at the centerline. The coherent structures are classified in terms of their topology. The non-coherent background field has flat energy spectra and normal distribution of velocity components. Most background field statistics depend only weakly on the type of structure on which they are superposed. It may be possible to adapt existing subgrid scale models to this decomposition.

Original languageEnglish (US)
Pages (from-to)301-328
Number of pages28
JournalFlow, Turbulence and Combustion
Issue number4
StatePublished - 2000

ASJC Scopus subject areas

  • General Chemical Engineering
  • General Physics and Astronomy
  • Physical and Theoretical Chemistry


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