{"id":432673,"date":"2025-05-27T19:40:04","date_gmt":"2025-05-27T19:40:04","guid":{"rendered":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/get-thread-invalid-id-integer-or-name-symbol-and-negative-cell-volume\/"},"modified":"2025-05-27T19:40:04","modified_gmt":"2025-05-27T19:40:04","slug":"get-thread-invalid-id-integer-or-name-symbol-and-negative-cell-volume","status":"publish","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/get-thread-invalid-id-integer-or-name-symbol-and-negative-cell-volume\/","title":{"rendered":"get-thread: invalid id (integer) or name (symbol) AND Negative Cell Volume"},"content":{"rendered":"<p>&lt;p&gt;Hello, everyone,&lt;\/p&gt;&lt;p&gt;I am performing a CFD simulation, to analyze acoustic noises from water flow in a valve, whose closing is described by a <strong>Dynamic Mesh<\/strong> and <strong>UDF<\/strong>.&lt;\/p&gt;&lt;p&gt;My mesh has <strong>7.5M<\/strong> elements, and minimum Orthogonal Quality of <strong>0.201<\/strong>. The UDF imposes moving 1mm\/s. Domain and zones are reordered using Reverse Cuthill McKee. The solver is Pressure-based, SIMPLE, Least Square Cell Based, Second Order, Second Order Upwind.&lt;\/p&gt;&lt;p&gt;For the Dynamic Mesh setup, I can activate Smoothing and Layering, but, when checking Remeshing, this error pops up: &lt;span style=&#8221;text-decoration: underline;&#8221;&gt;<em>get-thread: invalid id (integer) or name (symbol)<\/em>&lt;\/span&gt;&lt;\/p&gt;&lt;p&gt;I have tried running the simulation without Remeshing, but, as the mesh moves, the cells progressively lose quality and reach null orthogonal quality. Also, I have applied an execute command for <em>\/mesh\/repair-improve\/improve-quality<\/em> at the end of each time-step, combined with a time-step of 1e-6s, to at least maintain the quality during motion. However, the orthogonality still lowers to 0 and the <em>Negative Cell Volume Detected<\/em> error pops up.&lt;\/p&gt;&lt;p&gt;To identify where the problem was, I generated a mesh with the default sizes (400k cells), from the same SpaceClaim file as before. Proceeding with the same setup conditions, the Remeshing could now be activated, although it did not solve the <em>Negative Cell Volume<\/em> issue, which continued to show up.&lt;\/p&gt;&lt;p&gt;Would you please help me solve this problem? I have been several months into it, and it seems to have no way out.&lt;\/p&gt;&lt;p&gt;Thank you so much,&lt;\/p&gt;&lt;p&gt;Pedro&lt;\/p&gt;<\/p>\n","protected":false},"template":"","class_list":["post-432673","topic","type-topic","status-publish","hentry","topic-tag-dynamic-mesh","topic-tag-negative-cell-volume","topic-tag-Remesh-1","topic-tag-remeshing","topic-tag-thread-1","topic-tag-thread-id","topic-tag-udf"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_forum_id":["27796"],"_bbp_topic_id":["432673"],"_bbp_subscription":["522388","13659"],"_bbp_author_ip":["193.137.169.135"],"_bbp_last_reply_id":["432762"],"_bbp_last_active_id":["432762"],"_bbp_last_active_time":["2025-05-28 15:53:25"],"_bbp_reply_count":["5"],"_bbp_reply_count_hidden":["0"],"_bbp_voice_count":["2"],"_bbp_engagement":["522388","13659"],"_btv_view_count":["130"],"_bbp_topic_status":["unanswered"]},"test":"pedrolombardiperesgmail-com"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/432673","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\/432673\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=432673"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}