UDF in Cell Zone (Adjacent Cells)
 

Hello,

I am hooking a UDF onto a phase cell zone condition to fix the velocities in each cell which will depend on the adjacent cells' density. I am using DEFINE_PROFILE(name,thread,i) for this purpose. My workflow to achieve this in the UDF is:

1. Loop over all cells.
2. Within the loop, loop over all faces of each cell to get the face index and thread using C_FACE and C_FACE_THREAD
3. Using the face index and thread obtained, get the adjacent cell index and thread using F_C0, F_C0_THREAD and F_C1, F_C1_THREAD.
4. Using the cell index and thread, get the adjacent cell density (C_R).

I drafted my UDF with guidance from the manual. My problem is that when I try to initialize my case in Fluent, I get a an error "Received signal SIGSEGV". I have checked that the c_loop works using that Message, but when I enable the c_face_loop, initializing the case gives me the error. Interestingly, when I initialize the c_loop with check1, the error happens as well but initializing with check2 has no problem (the difference being that check2 is initialized during declaration.**

real check1, check2 =0;
begin_c_loop(c,thread)
{
* * *Message ("OK");
* * *// check1 =1;
* * *// check2 = 1;
* * *c_face_loop(c,thread,n)
* * *{
.......
}
}

May I know if the workflow for getting adjacent cell properties above is correct, and also what am I doing wrong in there? Thank you.

i think you don't need second loop (c_face_loop(c,thread,n))
use C_FACE and C_FACE_THREAD as a second step and continue with workflow

I've tried removing the c_face_loop, still does not work and gives me the "Received signal SIGSEGV" error when initializing.

show your code