{"id":238322,"date":"2022-10-21T09:23:50","date_gmt":"2022-10-21T09:23:50","guid":{"rendered":"\/forum\/forums\/topic\/floating-point-error-in-fgm-combustion-transient\/"},"modified":"2022-10-21T09:23:50","modified_gmt":"2022-10-21T09:23:50","slug":"floating-point-error-in-fgm-combustion-transient","status":"closed","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/floating-point-error-in-fgm-combustion-transient\/","title":{"rendered":"Floating Point Error in FGM combustion transient"},"content":{"rendered":"<p>Hi,&nbsp;<\/p>\n<p>I am currently performing a reacting case of a swirling combustor. My model is (partially premixed combustion) FGM diffusion model. I ran an initial steady case, and it worked perfectly fine converging well, and when comparing velocity profiles versus experiment, they were really good. I am now trying to do the same case but transient, to do this, I used my steady state solution and ran the transient case with a time step of 1e-6 to keep the courant number well below 1. The turbulence model used in k-e realizable. When running the transient case at the first time step, the solution diverges, and a floating point error is given. I am using a coupled solver with a very low URF, but I still have the same issue. I tried using SIMPLEC as well but still same error. I also tried to patch the progress variable to 1 and still diverged, and then tried to patch it to 0 and still diverged. Any ideas about what could be the issue and how to sort it out?<\/p>\n<p>Thank you,<\/p>\n<p>Nick&nbsp;<\/p>\n","protected":false},"template":"","class_list":["post-238322","topic","type-topic","status-closed","hentry","topic-tag-fluent-cfd-ansys-1","topic-tag-combustion-simulation-1","topic-tag-fgm","topic-tag-transient"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_subscription":["256086","199"],"_bbp_author_ip":["23.220.96.180"]," _bbp_last_reply_id":["0"]," _bbp_likes_count":["0"],"_btv_view_count":["779"],"_bbp_topic_status":["unanswered"],"_bbp_status":["publish"],"_bbp_topic_id":["238322"],"_bbp_forum_id":["27792"],"_bbp_engagement":["199","256086"],"_bbp_voice_count":["2"],"_bbp_reply_count":["8"],"_bbp_last_reply_id":["238506"],"_bbp_last_active_id":["238506"],"_bbp_last_active_time":["2022-10-24 08:30:43"]},"test":"6364efabeeef5556080a33c4b39700a3c8508bae"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/238322","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\/238322\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=238322"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}