{"id":304870,"date":"2023-09-04T18:43:15","date_gmt":"2023-09-04T18:43:15","guid":{"rendered":"\/forum\/forums\/topic\/negative-volume-detected-for-a-2-way-fsi\/"},"modified":"2023-09-04T18:43:15","modified_gmt":"2023-09-04T18:43:15","slug":"negative-volume-detected-for-a-2-way-fsi","status":"closed","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/negative-volume-detected-for-a-2-way-fsi\/","title":{"rendered":"&#8220;Negative Volume Detected&#8221; for a 2-way FSI."},"content":{"rendered":"<p>Hello,<br \/>I hope this post finds you well! I have been simulating a 2-way FSI (fluid structure interaction) of a single wall mounted flexible flap in a transverse flow. For a highly flexible filament (using respective properties in engineering material), the filament in my simulation touches the bottom wall of the fluid domain and the mesh collapses at that instance and the Fluent solver throws me an error &#8220;Negative Volume Detected&#8221;. Is there a way to fix this or resolve this issue? I believe I have to define a contact, so that ANSYS knows that there would be contact between the structure and the bottom wall after running for certain time when the oscillation is huge. However, I am not aware of how to define a contact in ANSYS, do I have to define it in Transient structural solver (solid solver) or ANSYS FLUENT solver (fluid solver), as I am using both the solvers using system coupling to perform a 2-way FSI simulation? If yes, how can i define a contact, kindly help on this? I would really appreciate any help. Please find the attached picture for your reference. (It shows the instant where the mesh collapses when the flexible filaments touch the bottom wall). Hoping to hear from you soon. Thank you!<img decoding=\"async\" src=\"\/forum\/wp-content\/uploads\/sites\/2\/2023\/09\/04-09-2023-1693852896-8757172576a979be91943df7031302497.jpg\" alt=\"\"><\/p>\n","protected":false},"template":"","class_list":["post-304870","topic","type-topic","status-closed","hentry"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_subscription":["18194","805","25526"],"_bbp_author_ip":["23.206.193.59"]," _bbp_last_reply_id":["0"]," _bbp_likes_count":["0"],"_btv_view_count":["496"],"_bbp_topic_status":["unanswered"],"_bbp_status":["publish"],"_bbp_topic_id":["304870"],"_bbp_forum_id":["27792"],"_bbp_engagement":["805","18194","25526"],"_bbp_voice_count":["3"],"_bbp_reply_count":["4"],"_bbp_last_reply_id":["307584"],"_bbp_last_active_id":["307584"],"_bbp_last_active_time":["2023-09-20 09:33:16"]},"test":"karankakroomy-unt-edu"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/304870","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\/304870\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=304870"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}