[cosimobianchini]

Hi all,
i'm working on k-epsilon LowRe turbulence model for compressible flow.
i was trying to implement the model proposed by Chien 1982, in which the damping function for mu depends on y+=y*u_tau/nu
where u_tau is the friction velocity, defined at the wall.

my question is:
do you have any suggestion on how to get y+ away from the wall?

thank you for your replies
cosimo

[mattijs]

Have a look at wallDist which is a volScalarField of the distance to the nearest wall. Additionally you could transport the flow properties at that same nearest wall (see wallDistData) and do your calculation.

[cosimobianchini]

Thank you really much Mattijs for answering.
Your suggestion was exactly what i was looking for.
I'll try to make it run for the Chien model and after that i was thinking about implementing a two layer turbulence model.
Since i'm a beginner in OF i was looking for some hints, do you maybe have some experience on this subject?
Thanks again for you help
cosimo

[braennstroem]

Hi,

I am trying to do the same as cosimo using:

wallPointYPlus::yPlusCutOff = 500;
wallDistData<wallpointyplus> y(mesh, Yplus);
Info << y.data() << endl;

This does unfortunately not work:

#0 Foam::error::printStack(Foam:stream&) in "/home/gcae504/OpenFOAM/OpenFOAM-1.5/lib/linux64GccDPOpt/libOpenFOAM.so"
#1 Foam::sigFpe::sigFpeHandler(int) in "/home/gcae504/OpenFOAM/OpenFOAM-1.5/lib/linux64GccDPOpt/libOpenFOAM.so"
#2 __restore_rt in "/lib64/tls/libc.so.6"
#3 Foam::FaceCellWave<foam::wallpointyplus>::faceToCe ll() in "/home/gcae504/OpenFOAM/gcae504-1.5/applications/bin/linux64GccDPOpt/computeYplu s"
#4 Foam::FaceCellWave<foam::wallpointyplus>::iterate( int) in "/home/gcae504/OpenFOAM/gcae504-1.5/applications/bin/linux64GccDPOpt/computeYplu s"
#5 Foam::FaceCellWave<foam::wallpointyplus>::FaceCell Wave(Foam::polyMesh const&, Foam::List<int> const&, Foam::List<foam::wallpointyplus> const&, Foam::UList<foam::wallpointyplus>&, Foam::UList<foam::wallpointyplus>&, int) in "/home/gcae504/OpenFOAM/gcae504-1.5/applications/bin/linux64GccDPOpt/computeYplu s"
#6 Foam::MeshWave<foam::wallpointyplus>::MeshWave(Foa m::polyMesh const&, Foam::List<int> const&, Foam::List<foam::wallpointyplus> const&, int) in "/home/gcae504/OpenFOAM/gcae504-1.5/applications/bin/linux64GccDPOpt/computeYplu s"
#7 Foam::patchDataWave<foam::wallpointyplus>::correct () in "/home/gcae504/OpenFOAM/gcae504-1.5/applications/bin/linux64GccDPOpt/computeYplu s"
#8 Foam::patchDataWave<foam::wallpointyplus>::patchDa taWave(Foam::polyMesh const&, Foam::HashSet<int,> > const&, Foam::List<foam::field<double>*> const&, bool) in "/home/gcae504/OpenFOAM/gcae504-1.5/applications/bin/linux64GccDPOpt/computeYplu s"
#9 Foam::wallDistData<foam::wallpointyplus>::correct( ) in "/home/gcae504/OpenFOAM/gcae504-1.5/applications/bin/linux64GccDPOpt/computeYplu s"
#10 Foam::wallDistData<foam::wallpointyplus>::wallDist Data(Foam::fvMesh const&, Foam::GeometricField<double,>&, bool) in "/home/gcae504/OpenFOAM/gcae504-1.5/applications/bin/linux64GccDPOpt/computeYplu s"
#11 main in "/home/gcae504/OpenFOAM/gcae504-1.5/applications/bin/linux64GccDPOpt/computeYplu s"
#12 __libc_start_main in "/lib64/tls/libc.so.6"
#13 __gxx_personality_v0 in "/home/gcae504/OpenFOAM/gcae504-1.5/applications/bin/linux64GccDPOpt/computeYplu s"
Floating exception (core dumped)


Would be nice, if anyone has a suggestion!?

Fabian