{"id":291061,"date":"2023-06-30T09:59:57","date_gmt":"2023-06-30T09:59:57","guid":{"rendered":"\/forum\/?post_type=topic&p=291061"},"modified":"2023-06-30T09:59:57","modified_gmt":"2023-06-30T09:59:57","slug":"combining-cg-motion-and-grid-motion-macros-in-fluent","status":"closed","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/combining-cg-motion-and-grid-motion-macros-in-fluent\/","title":{"rendered":"Combining CG Motion and Grid Motion Macros in Fluent"},"content":{"rendered":"

\"\"Hi there,<\/p>\n

I am trying to model a case in which one cell zone in my domain will undergo both rigid body motion and deforming motion. I have defined the rigid body motion in a UDF using the DEFINE_CG_MOTION macro, this motion is working fine. <\/p>\n

I have specified the deforming motion using the DEFINE_GRID_MOTION macro, I had a version of this UDF in which I was defining node positions on the deforming boundary explicitly, this did not work so I have modified this by using the NODE_COORD_NEST macro which I believe should specify the deforming motion relative to the CG motion of the whole zone.<\/p>\n

My workflow is to:<\/p>\n

    \n
  1. Compile DEFINE_CG_MOTION and DEFINE_GRID_MOTION macros.<\/li>\n
  2. Setup rigid body deformation on relevant cell zones.<\/li>\n
  3. Setup ‘user-specified’ mesh deformation on deforming boundary.<\/li>\n
  4. Set the user-specified mesh deformation to occur relative the CG motion of the adjacent cell zone.<\/li>\n<\/ol>\n

    This seems to be working in that I can clearly see CG motion as specified and I can also see motion of the boundary nodes. The issue is that, despite setting a deforming thread flag (SET_DEFORMING_THREAD_FLAG) to define the adjacent cell zone as deforming, I dont see any deformation of the interior mesh so I get inverted elements immediately. <\/p>\n

    Can anyone offer any advice? I have searched this forum and also dug through the documentation to no avail so any guidance would be appreciated!\"\"<\/p>\n

     <\/p>\n","protected":false},"template":"","class_list":["post-291061","topic","type-topic","status-closed","hentry","topic-tag-fluent-ansys-1","topic-tag-define_grid_motion-1","topic-tag-dynamic-mesh","topic-tag-udf"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_author_ip":["23.206.193.154"],"_bbp_subscription":["287740","18096"],"_btv_view_count":["1642"],"_bbp_topic_status":["unanswered"],"_bbp_status":["publish"],"_bbp_topic_id":["291061"],"_bbp_forum_id":["27792"],"_bbp_engagement":["18096","287740"],"_bbp_voice_count":["2"],"_bbp_reply_count":["1"],"_bbp_last_reply_id":["291864"],"_bbp_last_active_id":["291864"],"_bbp_last_active_time":["2023-07-06 11:08:44"]},"test":"christopher-passplymouth-ac-uk"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/291061","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\/291061\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=291061"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}