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-   -   OpenFOAM crashes using high resolution grid at wall (http://www.cfd-online.com/Forums/openfoam-solving/129969-openfoam-crashes-using-high-resolution-grid-wall.html)

Bazinga February 17, 2014 10:44

OpenFOAM crashes using high resolution grid at wall
 
Dear all,

I am really new to OpenFOAM, and after going through some of the tutorials I found the simpleFoam/turbineSiting tutorial which helped me to create a simulation with an atmospheric boundary layer (ABL).

For my own test simulation I wanna start with an empty domain with an ABL just going through it. This works fine for an uniform mesh of 0.1m in a 1.6x1.8x12m domain.

For my further studies it is necessary to have a high mesh resolution of the boundary layer at the bottom of the domain. So, I tried to put the node of the first cell at the bottom at about y+ = 30 which should be above the buffer layer to use wall functions for the viscous layer at the wall.

In my case I considered the freestream velocity as 6m/s, and the boundary length as 1.2m which gave me - using the cfd-online tool - a y+=30 wall distance of 0.0016m. However, when I make the mesh this dense at the bottom of my domain the simulation crashes in OpenFoam. Here is the errorcode if that helps:

Quote:

time step continuity errors : sum local = 3.59678e+85, global = 7.97804e+75, cumulative = 7.97804e+75
#0 Foam::error::printStack(Foam::Ostream&) in "/opt/openfoam222/platforms/linuxGccDPOpt/lib/libOpenFOAM.so"
#1 Foam::sigFpe::sigHandler(int) in "/opt/openfoam222/platforms/linuxGccDPOpt/lib/libOpenFOAM.so"
#2 Uninterpreted:
#3 Foam::multiply(Foam::Field<double>&, Foam::UList<double> const&, Foam::UList<double> const&) in "/opt/openfoam222/platforms/linuxGccDPOpt/lib/libOpenFOAM.so"
#4 void Foam::multiply<Foam::fvPatchField, Foam::volMesh>(Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh>&, Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh> const&, Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh> const&) in "/opt/openfoam222/platforms/linuxGccDPOpt/lib/libincompressibleTurbulenceModel.so"
#5 Foam::tmp<Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh> > Foam::operator*<Foam::fvPatchField, Foam::volMesh>(Foam::tmp<Foam::GeometricField<doub le, Foam::fvPatchField, Foam::volMesh> > const&, Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh> const&) in "/opt/openfoam222/platforms/linuxGccDPOpt/lib/libincompressibleRASModels.so"
#6 Foam::incompressible::RASModels::kEpsilon::correct () in "/opt/openfoam222/platforms/linuxGccDPOpt/lib/libincompressibleRASModels.so"
#7
in "/opt/openfoam222/platforms/linuxGccDPOpt/bin/simpleFoam"
#8 __libc_start_main in "/lib/i386-linux-gnu/libc.so.6"
#9
in "/opt/openfoam222/platforms/linuxGccDPOpt/bin/simpleFoam"
Floating point exception (core dumped)
The simulation settings are mostly copy pasted from the turbineSiting tutorial although I set the wall function for the bottom of the domain as:
nutkWallfunction for the walls
kqRWallFunction for k
epsilonWallFunction for eps
no-slip condition for U
zeroGradient for p

I also changed the inlet conditions of the ABL using Uref= 4 m/s, Href = 0,25m.

I am thankful for any comments regarding my thoughts about the simulations or hints why my denser mesh doesn't work.


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