[Rotidpor]

Hello everyone,


I am trying to sample surface scalar fields at a wall boundary. For this I'm using this sampleDict and :

buoyantSimpleFoam -postProcess -func sampleDict -latestTime


type surfaces;
libs ("libsampling.so");

setFormat raw;

surfaceFormat foam;

interpolationScheme cellPoint;

fields
(
T
mag_grad_O
);

sets
(
);

surfaces
(

w_cave
{
type patch;
patches ( w_cave );
triangulate false;
interpolate false;
}

);


It works fine for the usual "official" fields like T and U for example but I can't get it to work for custom fields. I'm just calculating the magnitude of the gradient of a passive scalar at this wall boundary.
Has someone an explanation ? The field I'm calculating is just a surface scalar field exactly like the temperature but I get this error message :

--> FOAM Warning :
From void Foam::sampledSurfaces::countFields()
in file sampledSurface/sampledSurfaces/sampledSurfaces.C at line 138

Cannot find registered field matching 1(mag_grad_O)

Well, I understand that it only works for the fields written by default with each solver but why is this ?? The last thing I want to do is using laplacianFoam -postProcess -func sampleDict (this solver writes by default the gradient of the variable) because it would force me to change the name of my field and calculate the magnitude myself... Which would not be efficient.

[Rotidpor]

I have found a way...


Just change the name of the field file to "k" for instance or any default written field of the solver, change the dimensions and it magically works.
But I feel guilty for fooling openfoam like that and I still don't get why it just doesn't simply work...