[nima_nz]

Hi
I have a UDF, that's for postprocessing; I have fluid cells and solid cells. In my UDF, I need velocity parameter that when I Execute the UDF on demand, FLUENT shows error. It's because of velocity parameter in the solid zone that doesn't exist. How can I fix this problem?
Thanks.

[`e`]

What UDF are you using for this postprocessing? You could extract the velocities for only the fluid domain (comment from your other thread).

[nima_nz]

Originally Posted by `e`

What UDF are you using for this postprocessing? You could extract the velocities for only the fluid domain (comment from your other thread).

Would you please tell me how I can extract velocities only for fluid domain?
Thanks for your help

[`e`]

Follow the instructions in your other thread and then read the velocities as normal. For example the x-velocity component:

C_U(c,t);

Which stage are you having trouble with and can you provide us with the UDF you are working with?

[Scram_1]

Hey,
I have written an execute_on_demand UDF for a simple geometry. It is a cube with dimensions 1cm X 1cm X 1cm.
When I run the UDF, it DOES NOT stop and keeps on running. Basically, what I eventually want to do is identify the wall mesh cells and calculate the minimum distance between a specific cell to the wall So, to debug the issue, I changed the code to print out the iteration number and it keeps on increasing without stopping. The zone numbers were taken from the boundary conditions window in fluent.
Here's the UDF:

#include "udf.h"
#include "sg.h"


DEFINE_ON_DEMAND(Test_UDF)
{
Domain *d; /*declare domain pointer since it is not passed in */
int zone_ID, iz;
Thread *t, *t0, *t_wall;
cell_t c, c0;
face_t f_wall;

d = Get_Domain(1); /*Get the domain using Fluent utility */

/*Loop over all cell threads in the domain*/
thread_loop_c(t, d)
{
int count = 1;
/*Loop over all cells*/
begin_c_loop(c, t)
{

for (iz = 19; iz <= 22; iz++)
{
if ((iz = 19) || (iz = 20) || (iz = 21) || (iz = 22)) /*if iz's value is belong to wall*/
{
zone_ID = iz;
t_wall = Lookup_Thread(d, zone_ID);

begin_f_loop(f_wall, t_wall)
{

printf("It works %d \n", count);
count = count+1;
}
end_f_loop(f_wall, t_wall)
/* end iz loop of multiple wall zones */
}
else /*for those not belongs to wall*/
{
;
}
}


} /*end c loop*/
end_c_loop(c, t)
} /*end thread loop*/

}

These are the mesh statistics:
Mesh Size

Level Cells Faces Nodes Partitions
0 64 240 125 1

1 cell zone, 7 face zones.

Thanks!!