{"id":404248,"date":"2025-01-09T13:02:26","date_gmt":"2025-01-09T13:02:26","guid":{"rendered":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/how-to-use-ansys-fluent-convergence-conditions\/"},"modified":"2025-01-09T13:45:54","modified_gmt":"2025-01-09T13:45:54","slug":"how-to-use-ansys-fluent-convergence-conditions","status":"publish","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/how-to-use-ansys-fluent-convergence-conditions\/","title":{"rendered":"How to use Ansys Fluent convergence conditions"},"content":{"rendered":"<p>&lt;p&gt;&lt;p&gt;Hello,&lt;\/p&gt;&lt;p&gt;I am running an Ansys transient simulation of flow around a bluff body to measure drag. I want to ensure the Cd has reached steady state, so I am trying to use convergence conditions.&lt;\/p&gt;&lt;p&gt;Im using an area weighted average of pressure distribtution over the body to determine when steady state has been reached. My timestep is 0.0001s, with 100,000 timesteps to allow more than enough time for convergence to be reached. I want the solution to converge when this pressure residual reaches 0.001, ignoring the first 0.14 seconds (1400 timesteps) and taking an average value over 0.2 seconds of flow time (2000 iterations). Thus, I filled in the convergence condition as follows:&lt;\/p&gt;&lt;p&gt;<img decoding=\"async\" src=\"https:\/\/innovationspace.ansys.com\/forum\/wp-content\/uploads\/sites\/2\/2025\/01\/09-01-2025-1736427141-mceclip0.png\" \/>&lt;\/p&gt;&lt;p&gt;I left it running overnight, however the solution &#8216;converged&#8217; at 0.398s (1398 timesteps).&nbsp; &lt;\/p&gt;&lt;p&gt;&lt;\/p&gt;&lt;p&gt;<img decoding=\"async\" src=\"https:\/\/innovationspace.ansys.com\/forum\/wp-content\/uploads\/sites\/2\/2025\/01\/09-01-2025-1736427517-mceclip1.png\" \/><img decoding=\"async\" src=\"https:\/\/innovationspace.ansys.com\/forum\/wp-content\/uploads\/sites\/2\/2025\/01\/09-01-2025-1736427587-mceclip2.png\" \/>&lt;\/p&gt;&lt;p&gt;&lt;\/p&gt;&lt;p&gt;Examining the plot, the results residual definitely did not fall within 0.001 and did not even reach 2000 timesteps? Did I fill in the convergence conditions wrong&lt;\/p&gt;&lt;p&gt;Thanks for you help.&lt;\/p&gt;&lt;p&gt; &lt;\/p&gt;&lt;p&gt; &lt;\/p&gt;&lt;p&gt; &lt;\/p&gt;&lt;\/p&gt;<\/p>\n","protected":false},"template":"","class_list":["post-404248","topic","type-topic","status-publish","hentry"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_forum_id":["27792"],"_bbp_topic_id":["404248"],"_bbp_subscription":["501435","199"],"_bbp_author_ip":["92.51.199.50"],"_bbp_last_reply_id":["404275"],"_bbp_last_active_id":["404275"],"_bbp_last_active_time":["2025-01-09 14:58:37"],"_bbp_reply_count":["4"],"_bbp_reply_count_hidden":["0"],"_bbp_voice_count":["2"],"_bbp_engagement":["501435","199"],"_btv_view_count":["1231"],"_bbp_topic_status":["unanswered"],"_edit_last":["501435"],"_bbp_revision_log":["a:1:{i:404254;a:2:{s:6:\"author\";i:501435;s:6:\"reason\";s:0:\"\";}}"]},"test":"amurphy3485gmail-com"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/404248","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":1,"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/404248\/revisions"}],"predecessor-version":[{"id":404254,"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/404248\/revisions\/404254"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=404248"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}