HI,

______________________________________________________

#include "udf.h"

DEFINE_PROFILE(unsteady_velocity, thread, position)

{

face_t f;

real t = CURRENT_TIME;

begin_f_loop(f, thread)

{

F_PROFILE(f, thread, position) = 0.02 + 0.005*sin(100.*t);

}

end_f_loop(f, thread)

}

______________________________________________________

Isn't this all what you need?

Regards,

Matevz

Hi,

If you want to simulate a flow following a sine wave with respect to time, you need a simple user defined function. Many example of similar kind can be found in UDF manual of Fluent.

Good luck!

/Sachin

Hi,

You can simulate both a transient velocity profile v=f(t) and a velocity profile depending on the coordinates of the system v=f(x,y,z) (or you can even combine these variants v=f(x,y,z,t)) using the DEFINE_PROFILE macro inf fluent.

If your velocity profile is time-dependent, you will have to use the simulation time in the velocity profile function (CURRENT_TIME).

If your velocity profile is location dependent, you will have to get the coordinates of the faces of the inlet boundary first.

As Sachin mentioned before, there are numerous examples for similar cases, so adapting one of these existing functions to your case would be the best option.

Thanks you friends...

I will work on that.

HI,

______________________________________________________

#include "udf.h"

DEFINE_PROFILE(unsteady_velocity, thread, position)

{

face_t f;

real t = CURRENT_TIME;

begin_f_loop(f, thread)

{

F_PROFILE(f, thread, position) = 0.02 + 0.005*sin(100.*t);

}

end_f_loop(f, thread)

}

______________________________________________________

Isn't this all what you need?

Regards,

Matevz

Look here: http://www.cfd-online.com/Forums/fluent/62766-how-generate-wave-fluent-3.html

A Sine wave flow input as boundary condition in fluent?

I want to know the unit of pi in the sin wave

F_PROFILE(f, thread, position) = 0.02 + 0.005*sin(2*pi*f*t);

so the value of pi is 3.14 or 180 ?