[miguwhynot]

Hi, I'm trying to set up and atmospheric air flow over a sphere, so I have a velocity inlet with the desired velocity and a pressure outlet with the UDF for pressure.

#include "udf.h"
DEFINE_PROFILE(pressure_inlet, thread, position)
{
face_t f;
real t = CURRENT_TIME;
real v = 4;
real t1 = 11000/v;
real t2 = 20000/v;
real t3 = 32000/v;
begin_f_loop(f, thread)
{
if (t <= t1)
{
F_PROFILE(f, thread, position) = 101325.0*pow(((288.15-0.0065*v*t)/288.15),5.25577);
}
else if (t <= t2)
{
F_PROFILE(f, thread, position) = 22605*pow(2.718281828,(11000-v*t)/6340);
}
else if (t <= t3) {
F_PROFILE(f, thread, position) = 2447*pow((141.89+0.003*v*t)/216.65,-11.388);
}
else {
// Capture t values outside the allowed range:
// print a message to the console and stop.
Message("%d: Error: t=%e not allowed.\n",myid,t);
return;
}
end_f_loop(f,thread)

}
}

As you can see the UDF basically simulates the ascendent move of the sphere at "v" velocity.

I'm having trouble making the problem work with no physic model turn on, just conitnuity (getting reverse flow at outlet). Can you spot my mistake over here?

Also I'm not completly sure what to set in Operating Condition pressure (I think the value should be zero since my UDF gives the total pressure value). Thanks everyone in Advance.