[antosan]

Hello,

I need to calculate the area of all faces within a given domain. What I did is the following:

1. To learn how to write the UDF, I looked into the ANSYS UDF MANUAL and I found a code that outputs a similar information for each face, i.e. the location of the centroids of the cells (page 225). This code is shown below (CODE 1). This code works and I am able to output a file with the centroid information.
2. When I adapt this code for outputting the area of each face within a domain, I receive a Segmentation fault. The adapted code is CODE 2, below. I debugged the code and the issue occurs when the code runs into the F_AREA(A,f,t) macro.
3. FYI- I am not running in parallel.

My approach is to compile the UDF and load it to DEFINE_ON_DEMAND.

I would appreciate if you give me any advice on this.
THANK YOU!
--------------------------------------------------------------------
CODE 1: IN ANSYS UDF MANUAL FOR CENTROID CALCULATION (WORKS)
-------------------------------------------------------------------
#include "udf.h"
FILE *fout;
void Print_Thread_Face_Centroids(Domain *domain, int id)
{
real FC[3];
face_t f;
Thread *t = Lookup_Thread(domain, id);
fprintf(fout,"thread id %d\n", id);
begin_f_loop(f,t)
{
F_CENTROID(FC,f,t);
fprintf(fout, "f%d %g %g %g\n", f, FC[0], FC[1], FC[2]);
}
end_f_loop(f,t)
fprintf(fout, "\n");
}
DEFINE_ON_DEMAND(get_coords)
{
Domain *domain;
domain = Get_Domain(1);
fout = fopen("faces.out", "w");
Print_Thread_Face_Centroids(domain, 23);
fclose(fout);
}
-----------------------------------------------------------------------
CODE 2: ADAPTATION FOR AREA CALCULATION (DOES NOT WORK)
------------------------------------------------------------------------
#include "udf.h"

FILE *fout;
void Print_Thread_Face_Area(Domain *domain, int id)
{
real NV_VEC(A);
face_t f;
Thread *t = Lookup_Thread(domain, id);
fprintf(fout,"thread id %d\n", id);
begin_f_loop(f,t)
{
fprintf(fout,"inside loop\n");
F_AREA(A,f,t);
/*fprintf(fout, "f%d %g \n", f, NV_MAG(A)); */
}
end_f_loop(f,t)
fprintf(fout, "\n");
}
DEFINE_ON_DEMAND(get_facearea)
{
Domain *domain;
domain = Get_Domain(1);
fout = fopen("faces_areas.out", "w");
Print_Thread_Face_Area(domain, 23);
fclose(fout);
}