{"id":383099,"date":"2024-09-19T07:46:31","date_gmt":"2024-09-19T07:46:31","guid":{"rendered":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/udf-for-reinjecting-particles\/"},"modified":"2024-09-19T07:46:31","modified_gmt":"2024-09-19T07:46:31","slug":"udf-for-reinjecting-particles","status":"publish","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/udf-for-reinjecting-particles\/","title":{"rendered":"UDF for reinjecting particles"},"content":{"rendered":"

<p><span style=”font-size: 12pt;”>Hi all,<\/span><br><br><span style=”font-size: 12pt;”>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)<\/span><br><br><span style=”font-size: 12pt;”>From my understanding:<\/span><br><span style=”font-size: 12pt;”>return PATH_END<\/strong> is used for considering particles escaped from the domain and<\/span><br><span style=”font-size: 12pt;”>return PATH_ACTIVE<\/strong> is for continuously tracking particles<\/span><br><br><span style=”font-size: 12pt;”>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<\/strong> seems to work as expected, PATH_ACTIVE<\/strong> does not. In the console, particles are being aborted.<\/span><br><br><span style=”font-size: 12pt;”>I have revised my code several times and attempted different solutions, but I am currently out of ideas.<\/span><br><br><span style=”font-size: 12pt;”>Would anyone be able to help me solve this issue or suggest any possible approaches? I would greatly appreciate your insights.<\/span><br><br><span style=”font-size: 12pt;”>Thank you in advance!<\/span><br><br><span style=”font-size: 12pt;”>Best regards,<\/span><br><span style=”font-size: 12pt;”>Dahae<\/span><br><br><span style=”font-size: 12pt;”>————————————————————–<\/span><br><span style=”font-size: 12pt;”>Here is my code FYI:<\/span><br><br><span style=”font-size: small;”>#include “udf.h”<br>#include “dpm.h”<br><br>#define REINJECT_POSITION_X 2.0 \/\/ Set the x-coordinate of the reinjection point<br>#define REINJECT_POSITION_Y 0.425 \/\/ Set the y-coordinate of the reinjection point<br>#define REINJECT_POSITION_Z 0.18 \/\/ Set the z-coordinate of the reinjection point<br><br>\/* Global variables *\/<br>int particle_count = 0;<br>int escaped_count = 0;<br>int reinjected_count = 0;<br><br>DEFINE_DPM_BC(udf_outlet, tp, t, f, f_normal, dim)<br>{<br>particle_count++;<br><br>if (particle_count <= 95)<br>{<br>\/* Mark as escaped *\/<br>escaped_count++;<br><br>return PATH_END;<br><br>}<br><br>if (particle_count > 95)<br>{<br>\/* Mark as reinjected *\/<br>reinjected_count++;<br><br>\/* Move particle to specific point *\/<br>P_POS(tp)[0] = REINJECT_POSITION_X; \/\/ Specific X position<br>P_POS(tp)[1] = REINJECT_POSITION_Y; \/\/ Specific Y position<br>P_POS(tp)[2] = REINJECT_POSITION_Z; \/\/ Specific Z position<br><br>return PATH_ACTIVE;<br>}<br><br>\/* Reset the counter after 100 particles *\/<br>if (particle_count > 100)<br>{<br>particle_count = 0;<br>escaped_count = 0;<br>reinjected_count = 0;<br>}<br><br>return PATH_ACTIVE;<br>}<\/span><\/p><\/p>\n","protected":false},"template":"","class_list":["post-383099","topic","type-topic","status-publish","hentry","topic-tag-dpm","topic-tag-dpm-tracking","topic-tag-dpm-udfs"],"aioseo_notices":[],"aioseo_head":"\n\t\t\n\t\n\t\n\t\n\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t