[naderafshar]

Hi everyone
I am simulating a circular plain channel in laminar flow (2D). The main challenge is that I want to move channel walls with a velocity equal to :
Uwall= -0.01*(dU/dy) (at wall)
I have written below UDF code. There is no error when I interpret it, but after I want to apply it on the walls, I see this error:
"Received signal SIGSEGV "
The code is:
#include "udf.h"
#include "mem.h"
#include "math.h"
real Q;
DEFINE_PROFILE(moving_wall, thread, i)
{
face_t f;
Thread*t;
cell_t c;
begin_f_loop(f, thread)
{
Q = C_DUDY(c,t);
F_PROFILE(f, thread, i)= -Q*0.0001;
}
end_f_loop(f, thread)
}
Please help me.
All the best