[lvanlee]

It was a simulation about mold electromagnetic stirring in continuous casting.
I worked out the lorentz force from Ansys Maxwell, now I want to add the lorentz force as source terms using the DEFINE_SOURCE macro.
So first, I need the cell centroid coordinates of the model mesh.
Then put the lorentz force on every coordinate as a momentum source.
So， how could I get the coordinates?
Thanks very much !

#include"udf.h"
FILE*fout;float xx[ND_ND];

DEFINE_ON_DEMAND(get_coords)
{
Domain *domain;
face_t f; cell_t c;Thread *t;
domain=Get_Domain(1);
t=Lookup_Thread(domain,2);
fout=fopen("faces.out","w");

if (fout==NULL)
Message("Can't open the file");

else

{ begin_c_loop(c,t)

{ F_CENTROID(xx,c,t);
fprintf(fout,"%d %g %g %g\n",c,xx[0],xx[1],xx[2]);
}
end_c_loop(c,t)

fprintf(fout,"\n");
fclose(fout);
}
}

this udf can't work out

[LuckyTran]

F_CENTROID gives the face centers. C_CENTROID gives the cell centers.

[lvanlee]

Originally Posted by LuckyTran

F_CENTROID gives the face centers. C_CENTROID gives the cell centers.

Thank you. It was a mistake and I use the C_CENTROID actually. But when I interpreted the UDF, it shows the "line 28: function "CX_Message" not found (pc=55).“ But I just have 27 lines, no line 28 at all.

[kavatar]

Hello,

Could you please tell which solver did you use in Ansys Maxwell to calculate the Lorentz Force? Was it Eddy Current Solver or Magnetic Transient Solver?

And did this UDF worked to apply the Lorentz Force in Ansys Fluent.

I am also working on similar kind of Problem. Your comment would be of great help to me.

Thanks in advance !!

[ssetay]

Hi,
I'm doing similar work, has your problem been solved?
Can i ask some questions？
Thinks！