{"id":460333,"date":"2026-06-25T17:29:36","date_gmt":"2026-06-25T17:29:36","guid":{"rendered":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/question-for-bcs\/"},"modified":"2026-06-25T17:29:36","modified_gmt":"2026-06-25T17:29:36","slug":"question-for-bcs","status":"publish","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/question-for-bcs\/","title":{"rendered":"Question for BCs"},"content":{"rendered":"<p>&lt;p&gt;I have a rigid body- cylinder tube with two holes which use as inlets, and the flow needs to enter in 1 sec into the domain by using the holes and the flow needs to be exit by the same hole in the 2nd second. In my opinion, I need to generate UDF. However, when I named the sections in meshing as inlets, walls. it gives me an error due to named selection. From my understanding th inlets and outlets need to be defined as different surface. If you have any idea, could you please explain? Thanks.&lt;\/p&gt;&lt;p&gt;&nbsp;&lt;\/p&gt;<\/p>\n","protected":false},"template":"","class_list":["post-460333","topic","type-topic","status-publish","hentry"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_forum_id":["27792"],"_bbp_topic_id":["460333"],"_bbp_author_ip":["8.226.1.108"],"_bbp_last_reply_id":["460423"],"_bbp_last_active_id":["460423"],"_bbp_last_active_time":["2026-06-26 21:04:34"],"_bbp_reply_count":["3"],"_bbp_reply_count_hidden":["0"],"_bbp_voice_count":["3"],"_bbp_engagement":["702898","199","199842"],"_btv_view_count":["31"],"_bbp_topic_status":["unanswered"],"_bbp_subscription":["199","199842","702898"]},"test":"mehm-sabr-27gmail-com"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/460333","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\/460333\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=460333"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}