# Computing LES variable

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 May 2, 2006, 19:38 Hi: I am running icoFoam #1 Member   Join Date: Mar 2009 Posts: 43 Rep Power: 10 Hi: I am running icoFoam. However, wanted to compute the turbulent variable 'nuSGS' without using the turbulence model. I tried to compute the following way: surfaceScalarField nusgs = sqrt(mesh().V()/thickness)*symm(grad(U)); computing the thickness variable as given in LESdeltas, but was not able to work it out. some errors include: error: no match for call to (Foam :: fvMesh) () error: grad was not declared in this scope.. Can someone elaborate on how to obtain this quantity? further, in the incompressible code, Can i Add this computed field to constant "nu" to make it an effective nueff = nu+nusgs. Thanks, Vatant

 May 3, 2006, 02:22 Why mesh().V() instead of mesh #2 Senior Member   Hrvoje Jasak Join Date: Mar 2009 Location: London, England Posts: 1,805 Rep Power: 25 Why mesh().V() instead of mesh.V()? I would also say Foam::sqrt and the rest looks OK. Hrv __________________ Hrvoje Jasak Providing commercial FOAM/OpenFOAM and CFD Consulting: http://wikki.co.uk

 May 3, 2006, 10:58 Hello Hrv: I tried to imple #3 Member   Join Date: Mar 2009 Posts: 43 Rep Power: 10 Hello Hrv: I tried to implement your suggestions. on Compiling, I received following errors: error: no match for 'operator*' in 'Foam::operator*(const Foam::scalar&, const Foam::tmp >&) [with Ty pe = double](((const Foam::tmp >&)((const Foam::tmp >*)(& Foam::sqrt(const Foam::UList &)())))) * Foam::symm(const Foam::GeometricField, PatchField, GeoMesh>&) [with PatchField = Foam::fvPatchField, G eoMesh = Foam::volMesh]()' I am not able to access mesh volume for some reason. Please let me know your thoughts on this. Thanks Vatant

 May 3, 2006, 11:20 Split it up and try bits of th #4 Senior Member   Hrvoje Jasak Join Date: Mar 2009 Location: London, England Posts: 1,805 Rep Power: 25 Split it up and try bits of the expression - not obvious like his... Hrv __________________ Hrvoje Jasak Providing commercial FOAM/OpenFOAM and CFD Consulting: http://wikki.co.uk

 May 3, 2006, 14:45 I tried to compute mesh.V(), m #5 Member   Join Date: Mar 2009 Posts: 43 Rep Power: 10 I tried to compute mesh.V(), mesh().V(),I keep getting the same error Foam::fvMesh problem. Is there any other way to access the cell structure? Regards, Vatant