Synthetic turbulence, Kinematic Simulation


ERCOFTAC - European Research Community on Flow, Turbulence and Combustion

Purpose and focus of the SIG

 

Synthetic models were developed in turbulence as an alternative to stochastic methods or direct numerical methods for Lagrangian applications.

SIG 42 was set up after it was realised that many research teams in Europe were using `synthetic turbulence models' and that there was a need form more interaction and unification between the different groups.

Most teams working on synthetic turbulence will be using Kinematic Simulation (KS).  KS is a unified Lagrangian model of one- and two- and indeed multi-particle turbulent dispersion where incompressibility is enforced by construction in the generation of every particle trajectory, the energy spectrum is prescribed according to the type of turbulence considered and where the effects of small-scale flow structure on Lagrangian statistics are taken into account.

As such, KS should be contrasted with Lagrangian stochastic models of turbulent diffusion which do not incorporate small-scale flow structure effects and which are by construction different models for one- and two-particle statistics.

KS is widely used in various domains, including

  • Lagrangian aspects in turbulence mixing/stirring,

  • particle dispersion/clustering,

  • aeroacoustics.

  • Flow realisations with complete spatial, and sometime spatio-temporal, dependence, are generated via superposition of random modes (mostly spatial, and sometime spatial and temporal, Fourier modes), with prescribed constraints such as: strict incompressibility (divergence-free velocity field at each point), high Reynolds energy spectrum, ...

    Recent improvements consisted in incorporating linear dynamics, for instance in rotating and/or stably-stratified flows, with possible easy generalisation to MHD flows, and perhaps to plasmas. On the other hand, the absence of "sweeping effects" in present conventional KS versions is identified as a major drawback in very different applications: inertial particle clustering as well as in aeroacoustics.

    Though most of the work involved in SIG 42 is done using KS, the SIG is open to other `synthetic turbulence'. People using other approaches to study particle dispersion or also welcome to participate in SIG 42's activities in particular to contribute to the different workshops.


    Topics

    A non-exhaustive list of topics the group is interesting in:

  • improvement of the modelling of small scales advection by largest scales (sweeping),

  • introduction of strongly anisotropic energy spectra with better randomization of the wave-vector,

  • analogy with initialisation of DNS/LES and with "Particle Representation Models",

  • use of specific modes consistent with geometric constraints, e.g. solid walls, instead of 3D spatial Fourier modes,

  • improvement of KS as a subgrid model for LES : Lagrangian diffusion and aeroacoustics,

  • competition between "wavy" (really spatio-temporal, propagating) and "vortical" structures of the velocity field for organizing Lagrangian turbulence diffusion, from fluid to plasma turbulence,

  • other "synthetic" models, e.g. to afford intermittency, possibly very different from conventional KS.


  • Steering committee

    Dr A. Baggaley
    Andrew.Baggaley@glasgow.ac.uk
    Department of Mathematics, University of Glasgow
    University Gardens
    Glasgow G12 8QW, United Kingdom
     
    Dr Dr K. Bajer
    Konrad.Bajer@fuw.edu.pl
    University of Warsaw,
    Institute of Geophysics
    ul. Pasteura 7
    02-093 Warsaw Poland
     
    Dr C. Cambon
    Claude.Cambon@ec-lyon.fr
    École Centrale de Lyon
    36, av. Guy de Collongues
    69134 Ecully cedex, France
     
    Dr T. M. Michelitsch
    michel@lmm.jussieu.fr
    Institut Jean le Rond d'Alembert, Université Pierre et Marie Curie
    Paris, France
     
    Dr F. Nicolleau (Coordinator)
    F.Nicolleau@sheffield.ac.uk
    University of Sheffield, Department of Mechanical Engineering
    Mappin Street
    Sheffield S1 3JD, United Kingdom
     
    Dr A. F. Nowakowski
    A.F.Nowakowski@sheffield.ac.uk
    University of Sheffield, Department of Mechanical Engineering
    Mappin Street
    Sheffield S1 3JD, United Kingdom
     
    Pr J.-M. Redondo
    redondo@fa.upc.edu
    Fisica Aplicada UPC,
    Campus Nord B5. Barcelona 08034, Spain
     
    Pr M. Reeks
    Mike.Reeks@newcastle.ac.uk
    School of Mechanical & Systems Engineering
    Stephenson Building
    Claremont Rd
    University of Newcastle upon Tyne
    Newcastle upon Tyne, NE1 7RU,  United Kingdom
     
    Pr J. C. Vassilicos
    j.c.vassilicos@ic.ac.uk,
    Imperial College of Science, London, Department of Aeronautics
    Prince Consort Road, South Kensington
    London SW7 2BY, United Kingdom
     

    Members

  • Ahmed. Abou ElAzm                                       University of Sheffield (UK)
  • E. Akylas                                               University of Cyprus, Mechanical & Manufacturing Engineering, Cyprus

  • Jean-Régis. Angilella                                          Nancy-Universités, LAEGO, France
  • Andrew Baggaley                                            University of Newcastle, School of Mathematics and Statistics
  • Konrad Bajer,                                                University of Warsaw, Poland
  • Claude Cambon                                             Ecole Centrale de Lyon, LMFA, (France)
  • R. Castilla,                                              UPC, Terrasa, (Spain)
  • Sergei. Chernyshenko                                     University of Southampton
  • S. Di Sabatino                                         Universita' di Lecce, (Italy)
  • Benjamin. Favier                                                 Ecole Centrale de Lyon, LMFA, (France)
  • R. Ijzermans                                           University of Newcastle, School of Mechanical & Systems Engineering, UK

  • M. Amirul. I. Khan                                          University of Glasgow, Department of Mathematics
  • David Kleinhans                                            University of Oldenburgh (Germany)
  • XiaoYu. Luo                                                University of Glasgow, Department of Mathematics
  • M. Manhart                                             Technische Universitaet Muenchen
  • Elena. Meneguz                                            University of Newcastle, School of Mechanical & Systems Engineering, UK

  • Thomas Michelitsch                                                Université Pierre et Marie Curie, Institut, Jean le Rond d'Alembert, France
  • Franck.C.G.A. Nicolleau                                  University of Sheffield, Department of Mechanical Engineering
  • Andrzej. F. Nowakowski                                  University of Sheffield, Mechanical Engineering, UK
  • Jose. M. Redondo                                        UPC, Barcelona (Spain)
  • Mike. Reeks                                                University of Newcastle
  • J. Christos. Vassilicos                                        Imperial College, Department of Aeronautics
  • Matthias. Wächter                                            Carl von Ossietzky University, Oldenburg, Germany
  • Hongwei. Zheng                                                University of Sheffield, Mechanical Engineering, UK


  • Workshops

     

  • Synthetic turbulence, clustering and fractal geometry (Paris, 28th - 29th June 2012)

  • How to assemble and disassemble turbulence and how do things assemble and disassemble in it? (London, 22nd-23rd September 2011)

  • Synthetic turbulence models and environment (Lyon, July 2010)

  • Synthetic turbulence models and vortex methods (Warsaw 1st-3rd July 2009)

  • Synthetic turbulence model and particle-laden flows (Nancy 11th-12th December 2008)

  • SIG 42 3rd workshop on Synthetic Turbulence (Newcastle 3rd-4th July 2008)

  • SIG 42 2nd workshop on Synthetic Turbulence (Barcelona 29th-30th November 2007)

  • SIG 35 1st workshop on Synthetic Turbulence (Sheffield 29th-30th May 2007)

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