1. 03 Aug, 2020 1 commit
  2. 03 Jan, 2020 1 commit
    • Kutalmis Bercin's avatar
      DEFEATURE: deprecate v2f model in favour of kEpsilonPhitF · ab0dd1f1
      Kutalmis Bercin authored
        - kEpsilonPhitF is a kEpsilon-based model which originated
          from (Durbin, 1995)’s v2-f methodology. However, the majority of
          v2-f model variants proved to be numerically stiff for segregated
          solution algorithms due to the coupled formulations of v2 and f fields,
          particularly on wall boundaries.
      
          The v2-f variant (i.e. OpenFOAM’s v2f model) due to
          (Lien and Kalitzin, 2001) reformulated the original v2-f model to enable
          segregated computations; however, a number of shortcomings regarding
          the model fidelity were reported in the literature.
      
          To overcome the shortcomings of the v2-f methodology, the v2-f approach
          was re-evaluated by (Laurence et al., 2005) by transforming v2 scale into
          its equivalent non-dimensional form, i.e. phit, to reduce the numerical
          stiffness.
          This variant, i.e. kEpsilonPhitF, is believed to provide numerical
          robustness, and insensitivity to grid anomalies while retaini...
      ab0dd1f1
  3. 18 Dec, 2019 1 commit
    • Kutalmis Bercin's avatar
      ENH: new RAS model: kEpsilonPhitF · e38e5d67
      Kutalmis Bercin authored
          ENH: modify fWallFunction for kEpsilonPhitF model
      
          The k-epsilon-phit-f turbulence closure model for incompressible and
          compressible flows.
      
          The model is a three-transport-equation linear-eddy-viscosity turbulence
          closure model alongside an elliptic relaxation equation:
            - Turbulent kinetic energy, \c k,
            - Turbulent kinetic energy dissipation rate, \c epsilon,
            - Normalised wall-normal fluctuating velocity scale, \c phit,
            - Elliptic relaxation factor, \c f.
      
          Reference:
          \verbatim
              Standard model (Tag:LUU):
                  Laurence, D. R., Uribe, J. C., & Utyuzhnikov, S. V. (2005).
                  A robust formulation of the v2−f model.
                  Flow, Turbulence and Combustion, 73(3-4), 169–185.
                  DOI:10.1007/s10494-005-1974-8
          \endverbatim
      
          The default model coefficients are (LUU:Eqs. 19-20):
          \verbatim
              kEpsilonPhitFCoeffs
              {
                  Cmu         0.22,    // Turbulent viscosity constant
                  Ceps1a      1.4,     // Model constant for epsilon
                  Ceps1b      1.0,     // Model constant for epsilon
                  Ceps1c      0.05,    // Model constant for epsilon
                  Ceps2       1.9,     // Model constant for epsilon
                  Cf1         1.4,     // Model constant for f
                  Cf2         0.3,     // Model constant for f
                  CL          0.25,    // Model constant for L
                  Ceta        110.0,   // Model constant for L
                  CT          6.0,     // Model constant for T
                  sigmaK      1.0,     // Turbulent Prandtl number for k
                  sigmaEps    1.3,     // Turbulent Prandtl number for epsilon
                  sigmaPhit   1.0,     // Turbulent Prandtl number for phit = sigmaK
              }
          \endverbatim
      
      Note
          The name of the original variable replacing 'v2' is 'phi' (LUU:Eq. 14).
          However, the name 'phi' preexisted in OpenFOAM; therefore, this name was
          replaced by 'phit'
      e38e5d67
  4. 31 Oct, 2019 1 commit
  5. 06 Feb, 2019 1 commit
  6. 23 Sep, 2016 1 commit
  7. 20 Sep, 2016 2 commits
    • Henry Weller's avatar
      9da9a78c
    • Henry Weller's avatar
      TurbulenceModels: Created a general base-class and selection mechanism for laminar stress models · 6b42dbae
      Henry Weller authored
      Renamed the original 'laminar' model to 'Stokes' to indicate it is a
      linear stress model supporting both Newtonian and non-Newtonian
      viscosity.
      
      This general framework will support linear, non-linear, visco-elastic
      etc. laminar transport models.
      
      For backward compatibility the 'Stokes' laminar stress model can be
      selected either the original 'laminar' 'simulationType'
      specification in turbulenceProperties:
      
          simulationType laminar;
      
      or using the new more general 'laminarModel' specification:
      
          simulationType laminar;
      
          laminar
          {
              laminarModel        Stokes;
          }
      
      which allows other laminar stress models to be selected.
      6b42dbae
  8. 29 Jul, 2016 2 commits
    • Henry Weller's avatar
      TurbulenceModels: Reorganized support macros to simplify the creation of... · 46ba7267
      Henry Weller authored
      TurbulenceModels: Reorganized support macros to simplify the creation of additional turbulence model libraries
      46ba7267
    • Henry Weller's avatar
      TurbulenceModels::kOmegaSSTLM: New correlation-based turbulent transition model · d9aa0561
      Henry Weller authored
      Description
          Langtry-Menter 4-equation transitional SST model
          based on the k-omega-SST RAS model.
      
          References:
              Langtry, R. B., & Menter, F. R. (2009).
              Correlation-based transition modeling for unstructured parallelized
              computational fluid dynamics codes.
              AIAA journal, 47(12), 2894-2906.
      
              Menter, F. R., Langtry, R., & Volker, S. (2006).
              Transition modelling for general purpose CFD codes.
              Flow, turbulence and combustion, 77(1-4), 277-303.
      
              Langtry, R. B. (2006).
              A correlation-based transition model using local variables for
              unstructured parallelized CFD codes.
              Phd. Thesis, Universität Stuttgart.
      
      Implemented by Henry G. Weller, CFD Direct in collaboration with Florian
      Schwertfirm, Kreuzinger und Manhart Turbulenz GmbH.
      d9aa0561
  9. 06 Jun, 2016 1 commit
    • Henry Weller's avatar
      kOmegaSSTDES: New DES model based on the k-omega SST RAS model · 34e48fff
      Henry Weller authored
      Description
          Implementation of the k-omega-SST-DES turbulence model for
          incompressible and compressible flows.
      
          DES model described in:
          \verbatim
              Menter, F. R., Kuntz, M., and Langtry, R. (2003).
              Ten Years of Industrial Experience with the SST Turbulence Model.
              Turbulence, Heat and Mass Transfer 4, ed: K. Hanjalic, Y. Nagano,
              & M. Tummers, Begell House, Inc., 625 - 632.
          \endverbatim
      
          Optional support for zonal filtering based on F1 or F2 is provided as
          described in the paper.
      
          For further details of the implementation of the base k-omega-SST model
          see Foam::kOmegaSST.
      
          The DES coefficient 'CDES' defaults to 0.61 but may be changed as
          necessary.
      
          The zonal filter filter defaults to '2' which uses "(1 - F2)" as
          suggested in the paper but '0' (no filtering) and '1' which uses
          "(1 - F1)" are also supported.
      34e48fff
  10. 30 Nov, 2015 1 commit
    • Andrew Heather's avatar
      CONTRIBUTION: Turbulence - new kOmegaSST DES, DDES and IDDES model variants · 43f91a14
      Andrew Heather authored
      - Initial code supplied by CFD Software E+F GmbH
      - Refactored and integrated into the new templated Turbulence structure
        by OpenCFD
      
      References:
      
      - kOmegaSSTDES model:
        Strelets, M. (2001)
        Detached Eddy Simulation of Massively Separated Flows,
        39th AIAA Aerospace Sciences Meeting and Exhibit, Reno, NV
      
      - kOmegaSSTDDES model:
        Gritskevich, M.S., Garbaruk, A.V., Schuetze, J., Menter, F.R. (2011)
        Development of DDES and IDDES  Formulations for the k-omega
        Shear Stress Transport Model, Flow, Turbulence and Combustion,
        pp. 1-19
      
      - kOmegaSSTIDDES model:
        Gritskevich, M.S., Garbaruk, A.V., Schuetze, J., Menter, F.R. (2011)
        Development of DDES and IDDES Formulations for the k-omega
        Shear Stress Transport Model, Flow, Turbulence and Combustion,
        pp. 1-19
      43f91a14
  11. 16 Feb, 2015 1 commit
  12. 14 Feb, 2015 2 commits
  13. 06 Feb, 2015 1 commit
  14. 28 Jan, 2015 1 commit
  15. 25 Jan, 2015 1 commit
  16. 24 Jan, 2015 2 commits
  17. 23 Jan, 2015 2 commits
  18. 22 Jan, 2015 1 commit
  19. 21 Jan, 2015 1 commit
    • Henry's avatar
      Updated the whole of OpenFOAM to use the new templated TurbulenceModels library · 2aec2496
      Henry authored
      The old separate incompressible and compressible libraries have been removed.
      
      Most of the commonly used RANS and LES models have been upgraded to the
      new framework but there are a few missing which will be added over the
      next few days, in particular the realizable k-epsilon model.  Some of
      the less common incompressible RANS models have been introduced into the
      new library instantiated for incompressible flow only.  If they prove to
      be generally useful they can be templated for compressible and
      multiphase application.
      
      The Spalart-Allmaras DDES and IDDES models have been thoroughly
      debugged, removing serious errors concerning the use of S rather than
      Omega.
      
      The compressible instances of the models have been augmented by a simple
      backward-compatible eddyDiffusivity model for thermal transport based on
      alphat and alphaEff.  This will be replaced with a separate run-time
      selectable thermal transport model framework in a few weeks.
      
      For simplicity and ease of maintenance and further development the
      turbulent transport and wall modeling is based on nut/nuEff rather than
      mut/muEff for compressible models so that all forms of turbulence models
      can use the same wall-functions and other BCs.
      
      All turbulence model selection made in the constant/turbulenceProperties
      dictionary with RAS and LES as sub-dictionaries rather than in separate
      files which added huge complexity for multiphase.
      
      All tutorials have been updated so study the changes and update your own
      cases by comparison with similar cases provided.
      
      Sorry for the inconvenience in the break in backward-compatibility but
      this update to the turbulence modeling is an essential step in the
      future of OpenFOAM to allow more models to be added and maintained for a
      wider range of cases and physics.  Over the next weeks and months more
      turbulence models will be added of single and multiphase flow, more
      additional sub-models and further development and testing of existing
      models.  I hope this brings benefits to all OpenFOAM users.
      
      Henry G. Weller
      2aec2496
  20. 19 Dec, 2014 1 commit
  21. 06 Aug, 2013 1 commit
  22. 01 Aug, 2013 2 commits
  23. 28 Jul, 2013 1 commit