oscillating flow
 

hello!

I would like to simulate oscillating flow through a nozzle, and the frequency is very high (approximately 1000-2000Hz).

I dont have any experience with that kind of simulations so I would like to know what is the best approach.

For instance how do I define velocity inlet with oscillating flow?

thanx for, I am sure I will have further questions!

BB

Re: oscillating flow
 

hi, you have to describe you velocity inlet with a UDF, just like this example (UDF MANUAL) /************************************************** ********************

unsteady.c

UDF for specifying a transient velocity profile boundary condition ************************************************** *********************/

#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) = 20. + 5.0*sin(10.*t);

} end_f_loop(f, thread) }

Re: oscillating flow
 

With so high frequency, it is better to use a turbulence model...set the mean velocity, and through the amplitude of oscillations you can fix the turbulence intensity....