[hsze]

Hello!
I'm modeling an airflow through a heated pipe in Fluent 18 and would like to recalculate the pipe wall temperature dependiong on the flow exit temperature at every iteration.
I've tried familarizing with UDFs to solve this issue. I'm able to recalculate the wall temperature with constants and set a profile with the define_profile function.
When I try accessing flow variables (after sucessfully interpreting and hooking the UDFs) with F_T(T(f,t) or when I try to access the geometry with F_AREA(A,f,t) I get a fatal signal everytime I try to run the simulation with a "segmentation fault".
Error: received a fatal signal (Segmentation fault).

Can you please tell me how to debugg this error?
I've also tried using F_UDMI(f,t,0) to save the temperature I want to access but I get the same error. (I thought it might be a memory problem?)

I'll post a few UDFs I've tried and sucesfully interpreted below.
Is this an approach or user issue from my side?

Thanks in advance!

First UDF (Temperature):
#include "udf.h"
/* Compute face temperature and store in user-defined memory */

DEFINE_EXECUTE_AT_END(t_out)
{
Domain *d;
Thread *t;
face_t f;
real temp;

d = Get_Domain(6);
t = Lookup_Thread(d, 11);


begin_f_loop(f,t)
{
temp = F_T(f,t);
F_UDMI(f,t,0) = (temp-923) / (1023-923);
}
end_f_loop(f,t)
}

Second UDF (Area):
#include "udf.h"
DEFINE_EXECUTE_AT_END(area_calculation)
{
Domain *d;
face_t f;
real A[ND_ND];
real area=0;
int ID = 11; /*this is the ID of the boundary wall that I want to get the temperature from*/
Thread *t;
int zone_ID;
d = Get_Domain(6);
t = Lookup_Thread(d,ID);
begin_f_loop(f,t)
{
F_AREA(A,f,t);
area = NV_MAG(A);
}
end_f_loop(f,t)
printf("area = %g\n",area);
}

Third UDF (Adjust to then set profile):
#include "udf.h"

Thread *out_surface_T;
face_t face;
real t_out=0.00;
real area_out=0.00;
real out_face;
real NV_VEC(area);



DEFINE_ADJUST(adjust,d)
{
d = Get_Domain(6);
out_surface_T=Lookup_Thread(d,11);
begin_f_loop(face,out_surface_T)
{
F_AREA(area,face,out_surface_T);
area_out+=NV_VEC(area);
t_out+=F_T(face,out_surface_T)*NV_VEC(area);
}
end_f_loop(face,out_surface_T)
out_face=t_out/area_out;
printf("after adjust %d/n", out_face);
}


DEFINE_PROFILE(inet_T,t,i)
{
face_t f;
begin_f_loop(f,t)
{
F_PROFILE(f,t,i)=out_face;
}
end_f_loop(f,thread)
printf("after profile %d/n", out_face);
}

[AlexanderZ]

was
d = Get_Domain(6);
to be

d = Get_Domain(1);

[hsze]

Originally Posted by AlexanderZ

was
d = Get_Domain(6);
to be

d = Get_Domain(1);

Thank you AlexanderZ!!
It works perfecclty now!