[JuBong]

In a square module with one cell of 0.001 m2, if the temperature T1 at the inlet is a function of T2 (the temperature of the next cell in the direction of exit), how to use UDF code to express T1 (y) = T2 (y) + 100 ?

example
#include "udf.h"
DEFINE_PROFILE(temperature, thread, position)
{
real x[ND_ND];
real y;
face_t f;
C_T(c,t);
begin_f_loop(f, thread)
{
F_CENTROID(x,f,thread);
y = x[1];
F_PROFILE(f, thread, position) = C_T(c,t) + 100;
}
end_f_loop(f, thread)
}

[doruk]

Hello,

I have never done anything like this but I changed your code hope this works for you.

DEFINE_PROFILE(temperature, thread, position)
{
Thread *t0;
face_t f;
cell_t c0;

begin_f_loop (f,thread)
{

c0=F_C0(f,thread); // adjacent cell id
t0 = F_C0_THREAD(f,thread); // adjacent cell thread

F_T(f,thread)=C_T(c0,t0)+100;

}
end_f_loop (f,thread)
}

Problem with your code is you are trying to use the cell values in face loop. There are some specific macros designed to be used for cases likes yours such as the adjacent macros I wrote above.

You can check the user guide if you want to know more about adjacent cells.

I hope this fixes your issues.

Best Regards
Doruk