{"id":442815,"date":"2025-10-01T17:22:36","date_gmt":"2025-10-01T17:22:36","guid":{"rendered":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/structural-domain-setup-in-fsi-large-deflection-setting\/"},"modified":"2025-10-01T17:22:36","modified_gmt":"2025-10-01T17:22:36","slug":"structural-domain-setup-in-fsi-large-deflection-setting","status":"publish","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/structural-domain-setup-in-fsi-large-deflection-setting\/","title":{"rendered":"Structural Domain Setup in FSI (Large Deflection Setting)"},"content":{"rendered":"

<p data-start=”109″ data-end=”280″>In my analysis, I’m working with FSI where flexible flaps are installed inside an internal flow channel to investigate the heat transfer enhancement on the channel wall.<\/p><p data-start=”282″ data-end=”369″>I have a question regarding the <strong data-start=”314″ data-end=”334″>Large Deflection<\/strong> option in the structural domain:<\/p><ul data-start=”370″ data-end=”680″><li data-start=”370″ data-end=”483″><p data-start=”372″ data-end=”483″>When this setting is <strong data-start=”393″ data-end=”404″>enabled<\/strong> vs. <strong data-start=”409″ data-end=”421″>disabled<\/strong>, what are the practical effects in this type of simulation?<\/p><\/li>\n

<li data-start=”484″ data-end=”680″><p data-start=”486″ data-end=”680″>Both cases allow the flaps to deform, but with <strong data-start=”533″ data-end=”562″>Large Deflection disabled<\/strong>, the structural solver seems to converge more easily. Could this cause other issues or inaccuracies in the results?<\/p><\/li>\n<\/ul>\n

<p data-start=”682″ data-end=”873″>Currently, I am facing difficulties with <strong data-start=”723″ data-end=”761″>very low Young’s modulus materials<\/strong>, which often leads to structural divergence. To handle this, I’ve been disabling the Large Deflection option.<\/p><p data-start=”875″ data-end=”897″>So my questions are:<\/p><\/p>\n

    <li data-start=”898″ data-end=”1027″><p data-start=”901″ data-end=”1027″>Other than disabling Large Deflection, are there additional methods to improve convergence when using low modulus materials?<\/p><\/li>\n

    <li data-start=”1028″ data-end=”1146″><p data-start=”1031″ data-end=”1146″>I’ve already reduced the time step to 0.0001 and relaxed the tolerances, but the divergence issue still persists.<\/p><\/li>\n<\/ol>\n

    <p data-start=”1148″ data-end=”1210″>Any suggestions or experiences would be greatly appreciated!<\/p><\/p>\n","protected":false},"template":"","class_list":["post-442815","topic","type-topic","status-publish","hentry","topic-tag-Structuredmeshing-2","topic-tag-2-way-fsi","topic-tag-fluent"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_forum_id":["27792"],"_bbp_topic_id":["442815"],"_bbp_subscription":["491544","13659"],"_bbp_author_ip":["2402:7500:4d5:aef4:4c87:c7d9:6633:b3ae"],"_bbp_last_reply_id":["442987"],"_bbp_last_active_id":["442987"],"_bbp_last_active_time":["2025-10-03 17:18:35"],"_bbp_reply_count":["5"],"_bbp_reply_count_hidden":["0"],"_bbp_voice_count":["2"],"_bbp_engagement":["491544","13659"],"_btv_view_count":["90"],"_bbp_topic_status":["unanswered"]},"test":"1f7a2b4b2266cd3ea377374d79e788702db8097b"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/442815","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\/442815\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=442815"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}