{"id":309389,"date":"2023-09-29T09:56:44","date_gmt":"2023-09-29T09:56:44","guid":{"rendered":"\/forum\/forums\/topic\/further-clarification-on-tp_vel0-data-structure\/"},"modified":"2023-09-29T10:31:21","modified_gmt":"2023-09-29T10:31:21","slug":"further-clarification-on-tp_vel0-data-structure","status":"closed","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/further-clarification-on-tp_vel0-data-structure\/","title":{"rendered":"Further clarification on TP_VEL0 data structure"},"content":{"rendered":"<p>Dear,&nbsp;<\/p>\n<p>I have a question regarding the data structure of TP_VEL0, which in the UDF manual is defined as the location where the particles data is saved at the beginning of the timestep or at the entrance of the cell.&nbsp;<\/p>\n<p>Moreover, in the UDF example of a particle reflection at a boundary which uses the DEFINE_DPM_BC macro, after calculating the normal velocity of the particle and assigning it to the current particle velocity TP_VEL it also assigns it in TP_VEL0. My questions is why is the last assignment taking place?&nbsp;<\/p>\n<p>I think this is because you need the TP_VEL and TP_VEL0 at every timestep to calculate particle&#8217;s acceleration. Thus, it assigns the reflected velocity of the particle to TP_VEL0 as well because this value is going to be used as the initial velocity at the next flow timestep. Is it correct?<\/p>\n<p>Last but no least, the particle time TP_TIME(tp) is the particle residence time?<\/p>\n<p>Kind regards,&nbsp;<\/p>\n<p>Thodoris<\/p>\n","protected":false},"template":"","class_list":["post-309389","topic","type-topic","status-closed","hentry","topic-tag-dpm","topic-tag-udf"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_subscription":["37092","199"],"_bbp_author_ip":["23.206.193.59"]," _bbp_last_reply_id":["0"]," _bbp_likes_count":["0"],"_btv_view_count":["318"],"_edit_lock":["1695983468:180404"],"_bbp_topic_status":["unanswered"],"_bbp_status":["publish"],"_bbp_topic_id":["309389"],"_bbp_forum_id":["27792"],"_bbp_engagement":["199","37092"],"_bbp_voice_count":["2"],"_bbp_reply_count":["1"],"_bbp_last_reply_id":["309406"],"_bbp_last_active_id":["309406"],"_bbp_last_active_time":["2023-09-29 12:50:05"]},"test":"theodoros-dimaskuleuven-be"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/309389","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics"}],"about":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/types\/topic"}],"version-history":[{"count":0,"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/309389\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=309389"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}