[fandall]

Hy everyone, just created my first genuine BlockMesh. Is created fine and without any errors in FoamX.
But after assigning all boundary conditions, paraFoam gives me an error message, stating that not all boundary conditions necessary are specified, thus refusing loading of the mesh. After revision of all files, I couldn't find any missing boundary conditions...
I'm attempting to calculate natural convection in a vertical rectangular duct with only a small inlet/outlet and fixed wall temperature using buoyantFoam.

The error message reads as follows:
"--> FOAM FATAL IO ERROR :
Cannot find 'value' entry which is required to set the values of the default patch field.

Please add the 'value' entry to the write function of the user-defined boundary-condition
or link the boundary-condition into libfoamUtil.so

file: /opt/OpenFOAM/root-1.2/run/shaftVentilation//shaftVentilation/0/p::floorwalls from line 36 to line 36.

From function defaultFvPatchField<type>::defaultFvPatchField(con st fvPatch&, const Field<type>&, const dictionary&)
in file fields/fvPatchFields/basicFvPatchFields/default/defaultFvPatchField.C at line 127.

FOAM exiting"

I parked my files here, if you want to take a look at them: http://n.ethz.ch/student/rohnerth/do.../shaftVent.zip

Oddly enough, the simulation can be run, but a problem arises nonetheless, the maximal courant number seems to be ever increasing over time, but not linearly. Is it ok to have local courant numbers of 2 to 3 or will it explode? (I am not that experienced in turbulent flow computation)

Thx in advance for any advice!
Greetings Thomas

[fandall]

Trying to load the case in paraFoam for post-processing yields the same error message...
I just don't understand this message. There is no 'value' to be specified as I am using 'wallBuoyantPressure' as the boundary condition on any wall except the vent opening. I'm really confused now...

Computation run finished without interruption or any errors and the maximal courant number came back below 1, so this concern doesn't appear to be an issue :-)

Still it would be nice to know how to fix this, as I am burning to know if what I computed is as expected, so any advice is welcome!
Greetings Thomas

[david_h]

Thomas,

You might need to add a "value" entry for the "wallBuoyantPressure" boundary condition, similar to what is described for the "waveTransmissive" boundary condition on the wiki:

http://openfoamwiki.net/index.php/HowTo_Using_the_WaveTransmissive_Boundary_cond ition

Alternatively, you could try sending the "-latestTime" or "-time X" directives to foamToVTK and use the standard paraview.

Dave

[fandall]

Thanks for the quick answer, I'll try these out.
Sorry for answering so late, my internet connection at home is down at the moment :-(

[fandall]

So, adding the value entry in a Text Editor did solve this Problem. Awkwardly, FoamX doesn't permit to add those values and if you save the case in FoamX after you edited the file manually, the value entries had disappeared...
Anyway, thanks for the help!