[Diegoesteban]

Hi!
I need a UDF to define two inlet boundary conditions (mass flowrate and pressure) in a surface. Can anyone help please?

[A CFD free user]

Hi,
You can do it using a DEFINE_PROFILE macro. First, flag the thread you want to define these two B.C and apply a f_loop macro over all the faces in the thread and finally prescribe your own formulas employing a predefined F_PROFILE macro. Have a look at the examples provided by Fluent. They can be useful.
Not complicated.

Here's an example:

#include "udf.h"
DEFINE_PROFILE(pressure_profile, t, i)
{
real x[ND_ND]; /* this will hold the position vector */
real y;
face_t f;
begin_f_loop(f, t)
{
F_CENTROID(x,f,t);
y = x[1];
F_PROFILE(f, t, i) = 1.1e5 - y*y/(.0745*.0745)*0.1e5;
}
end_f_loop(f, t)
}

[Diegoesteban]

thank you very much! I'll try to create the UDF!