code_saturne User's Forum

Hello,

I am starting some research regarding heat transfer in turbulent flows. I noticed that it is not possible to use the Generalized Gradient Diffusion Hypothesis (GGDH) (or AFM, DFM) with the k-omega SST model. Is there any particular reason why this is the case.

Regards,

Matt

Hello,

I'll remind my colleagues working on turbulence modelling to check your question. From short discussions I had with them, I understand that using GGDH, AFM, or DFM with k-omega SST could be done, but work has been focused more on other turbulence models, so these models have not been implemented for k-omega as of today.

Regards,

Yvan

I guess it's because all these closures (GGDH, AFM, DFM) are suitable for non-isotropic turbulence, that you can only reproduce using a Reynolds Stress Model for the turbulent momentum field. Eddy-viscosity models like k-omega SST cannot reproduce turbulence anisotropy (at least when using a linear constituve relationship for Rij, as it is the case in code saturne), and therefore only the isotropic SGDH is available for the closure of the turbulent scalr flux.

Andrea