apply velocities on part of the boundary faces
 

Hi,
I want to apply a velocity boundary condition at the inlet of a 3D geometry by using UDF. There are 17478 faces on the inlet boundary. I don’t want to go over all faces by face loop. Instead, I only applied velocities specifically to 3520 faces and ask Fluent to interpolate for the rest faces. The problem is, the velocities shown in the Velocity Contour dialog box after iteration are different from what I applied to the boundary. What is wrong with it?
The corresponding UDF is as follows:
begin_f_loop(f,t)
{
for (j=0;j<3520;j++)
{
if(f==point_list[j].f)
{
F_PROFILE(f, t, index) = uvel[j][1];
}
}
}
end_f_loop(f,t)
Here, point_list[j] is the array that stores the index number of 3520 faces. Uvel[j][1] is the velocity that I want to apply.
Thanks a lot.