[feri_phd]

Hello cfd online members,

I want to give the initial temperature value on surfaces on my model. I wrote udf code. it works fine for one geometry whereas another model has never work. I tried some things. and I changed the face ID for the new model. To be clear, I will give the steps I did.

1). I wrote udf code as follow;
#include "udf.h"
DEFINE_INIT(my_init_funcf7,domain)
{
real F_T;
face_t f;
int ID=15;
/* loop over all cell threads in the domain */
Thread *thread = Lookup_Thread(domain,ID);
#if RP_NODE
begin_f_loop(f,thread)
{
F_T(f,thread)=374;
}
end_f_loop_all(f,thread)
#endif
}
//f8
DEFINE_INIT(my_init_funcf8,domain)
{
real F_T;
face_t f;
int ID=16;
/* loop over all cell threads in the domain */
Thread *thread = Lookup_Thread(domain,ID);
#if RP_NODE
begin_f_loop(f,thread)
{
F_T(f,thread)=373;
}
end_f_loop_all(f,thread)
#endif
}

2) interpreted to udf and the hooking is done
3). the standard initialization is achieved.

These steps worked fine with one model but for another model doesn't work. I tried another type udf as follows. but it doesn't work still.

#include "udf.h"
DEFINE_INIT(my_init_funcb5,domain)
{
int F_T;
face_t f;
int ID=70;
Thread *t1 = Lookup_Thread(domain,9);
Thread *t2 = Lookup_Thread(domain,10);
thread_loop_f(t1, domain)/* loops over all face threads in a domain*/
{
begin_f_loop(f,t1)
{
F_T(f,t1)=436;
}
end_f_loop_all(f,t)
}
thread_loop_f(t2, domain)/* loops over all face threads in a domain*/
{
begin_f_loop(f,t2)
{
F_T(f,t1)=436;
}
end_f_loop_all(f,t)
}
}


thank you

[pakk]

When you say that the code does not work for a geometry, what does that mean? It crashes, it gives wrong results, it gives no results, the simulation diverges... Which one is it?

[feri_phd]

Originally Posted by pakk

When you say that the code does not work for a geometry, what does that mean? It crashes, it gives wrong results, it gives no results, the simulation diverges... Which one is it?

Hello pakk,
it doesn't assign specfied temperatures to faces. it initializes with operating temperature.

[pakk]

Then I can only guess that the thread id is different in the other geometry.

[AlexanderZ]

as you've defined threads explicitly in your code
you don't need to loop over thread anymore
for thread with ID 9 and 10 your code looks like this:
(values 9 and 10 are ddifferent for each case, check in fluent graphical interface)

#include "udf.h"
DEFINE_INIT(my_init_funcb5,domain)
{
face_t f;

Thread *t1 = Lookup_Thread(domain,9);
Thread *t2 = Lookup_Thread(domain,10);

begin_f_loop(f,t1)
{
	F_T(f,t1)=436;
}
end_f_loop_all(f,t1)


begin_f_loop(f,t2)
{
	F_T(f,t2)=436;
}
end_f_loop_all(f,t2)

}