{"id":373700,"date":"2024-07-26T01:38:00","date_gmt":"2024-07-26T01:38:00","guid":{"rendered":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/improving-convergence-in-two-way-fsi-simulations-achieving-consistent-sinusoida\/"},"modified":"2024-07-26T01:38:00","modified_gmt":"2024-07-26T01:38:00","slug":"improving-convergence-in-two-way-fsi-simulations-achieving-consistent-sinusoida","status":"closed","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/improving-convergence-in-two-way-fsi-simulations-achieving-consistent-sinusoida\/","title":{"rendered":"Improving Convergence in Two-Way FSI Simulations: Achieving Consistent Sinusoida"},"content":{"rendered":"<div class=\"flex-shrink-0 flex flex-col relative items-end\">\n<div>\n<div class=\"pt-0\">\n<div class=\"gizmo-bot-avatar flex h-8 w-8 items-center justify-center overflow-hidden rounded-full\">\n<div class=\"relative p-1 rounded-sm flex items-center justify-center bg-token-main-surface-primary text-token-text-primary h-8 w-8\">Hello folks!&nbsp;<\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<div class=\"group\/conversation-turn relative flex w-full min-w-0 flex-col agent-turn\">\n<div class=\"flex-col gap-1 md:gap-3\">\n<div class=\"flex flex-grow flex-col max-w-full\">\n<div class=\"min-h-[20px] text-message flex w-full flex-col items-end gap-2 whitespace-pre-wrap break-words [.text-message+&amp;]:mt-5 overflow-x-auto\" dir=\"auto\" data-message-author-role=\"assistant\" data-message-id=\"0c84c265-03c5-48af-8c5c-7efd0efa882c\">\n<div class=\"flex w-full flex-col gap-1 empty:hidden first:pt-[3px]\">\n<div class=\"markdown prose w-full break-words dark:prose-invert light\">\n<p>I&#8217;m running a two-way FSI simulation but don&#8217;t know much about convergence. Here are my current settings and issues:<\/p>\n<ul>\n<li>\n<p><strong>Current Settings:<\/strong><\/p>\n<ul>\n<li>URF (Under-Relaxation Factor): 0.15 (from fluid to structural)<\/li>\n<li>RMS Convergence Target: 1e-7<\/li>\n<\/ul>\n<\/li>\n<li>\n<p><strong>Issues:<\/strong><\/p>\n<ul>\n<li>The graphs should both look sinusoidal, but the sinusoidal pattern in the fluid is more visible (larger) compared to the structural.<\/li>\n<li>Changing RMS to 0.2 resulted in a &#8220;negative cell volume error.&#8221;<\/li>\n<li>Increasing the Young&#8217;s modulus allows for a slightly higher URF, but the issue with the graphs persists.<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<p><img decoding=\"async\" src=\"https:\/\/innovationspace.ansys.com\/forum\/wp-content\/uploads\/sites\/2\/2024\/07\/26-07-2024-1721957522-mceclip0.png\"><\/p>\n<p>Which factors should I change to make both graphs look alike (sinusoidal)?<\/p>\n","protected":false},"template":"","class_list":["post-373700","topic","type-topic","status-closed","hentry","topic-tag-convergence","topic-tag-rms","topic-tag-two-way-fsi-1","topic-tag-under-relaxation-factor-1"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_subscription":["431728","13659"],"_bbp_author_ip":["130.215.190.183"]," _bbp_last_reply_id":["0"],"_btv_view_count":["309"]," _bbp_likes_count":["0"],"_bbp_topic_status":["unanswered"],"_bbp_topic_id":["373700"],"_bbp_forum_id":["27792"],"_bbp_engagement":["13659","431728"],"_bbp_voice_count":["2"],"_bbp_reply_count":["2"],"_bbp_last_reply_id":["373785"],"_bbp_last_active_id":["373785"],"_bbp_last_active_time":["2024-07-26 12:47:46"]},"test":"751ef47ef94a7db2035eda1dd10abecb4b252174"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/373700","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\/373700\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=373700"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}