[dseong]

Hi all,

I am working on creating a UDF to track particles hitting the outlet boundary. The setup involved in an air purifier in a small chamber, and I aim to set the purifier's efficiency at 95%. (95% of the particles that reach the outlet will escape, while 5% will be reinjected from a reinjection point)

From my understanding:
return PATH_END is used for considering particles escaped from the domain and
return PATH_ACTIVE is for continuously tracking particles

I would like to set up the system so that 5% of particles are reinjected from the reinjection point and continue being tracked. While PATH_END seems to work as expected, PATH_ACTIVE does not. In the console, particles are being aborted.

I have revised my code several times and attempted different solutions, but I am currently out of ideas.

Would anyone be able to help me solve this issue or suggest any possible approaches? I would greatly appreciate your insights.

Thanks you in advance!

Best regards,
Dahae

--------------------------------------------------------------
Here is my code FYI:

#include "udf.h"
#include "dpm.h"

#define REINJECT_POSITION_X 2.0 // Set the x-coordinate of the reinjection point
#define REINJECT_POSITION_Y 0.425 // Set the y-coordinate of the reinjection point
#define REINJECT_POSITION_Z 0.18 // Set the z-coordinate of the reinjection point

/* Global variables */
int particle_count = 0;
int escaped_count = 0;
int reinjected_count = 0;

DEFINE_DPM_BC(udf_outlet, tp, t, f, f_normal, dim)
{
particle_count++;

if (particle_count <= 95)
{
/* Mark as escaped */
escaped_count++;

return PATH_END;

}

if (particle_count > 95)
{
/* Mark as reinjected */
reinjected_count++;

/* Move particle to specific point */
P_POS(tp)[0] = REINJECT_POSITION_X; // Specific X position
P_POS(tp)[1] = REINJECT_POSITION_Y; // Specific Y position
P_POS(tp)[2] = REINJECT_POSITION_Z; // Specific Z position

return PATH_ACTIVE;
}

/* Reset the counter after 100 particles */
if (particle_count > 100)
{
particle_count = 0;
escaped_count = 0;
reinjected_count = 0;
}

return PATH_ACTIVE;
}