{"id":453949,"date":"2026-03-08T20:09:54","date_gmt":"2026-03-08T20:09:54","guid":{"rendered":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/vof-evaporation-causes-floating-point-exception\/"},"modified":"2026-03-08T20:12:49","modified_gmt":"2026-03-08T20:12:49","slug":"vof-evaporation-causes-floating-point-exception","status":"publish","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/vof-evaporation-causes-floating-point-exception\/","title":{"rendered":"VOF evaporation causes &#8220;floating point exception&#8221;"},"content":{"rendered":"<p>&lt;p&gt;&lt;p&gt;&lt;p&gt;I am running a VOF-to-DPM simulation similar to this <a href=\"https:\/\/www.youtube.com\/watch?v=S0MUu2svgQ8\">video<\/a> but with evaporating liquid and droplet DPM instead of inert. Its a case of two impinging liquid jets, where one is ethanol\/water mixture and the other is liquid oxygen. The simulation runs fine, except when I enable enable evaporation\/condensation in the Multiphase menu (interface heat flux method), even if the temperature in the entire domain stays below the saturation temperture of the liquid. I get &#8220;floating point exception&#8221; consistantly around the time the liquid jets enter the main impingment zone, where the mesh adaption takes place, so I think its likely related. I have tried the Lee evaporation model and get the same result.&lt;\/p&gt;&lt;p&gt;Here is how the adaptive mesh is defined&lt;\/p&gt;&lt;p&gt;REFINE&lt;\/p&gt;&lt;p&gt;Type: Cells More Than&lt;\/p&gt;&lt;p&gt;Derivative Option: Curvature&lt;\/p&gt;&lt;p&gt;Curvature of: Phases, volume fraction&lt;\/p&gt;&lt;p&gt;Phase: ethanol\/water or liquid oxygen&lt;\/p&gt;&lt;p&gt;Cells having value more than: 1e-10&lt;\/p&gt;&lt;p&gt;COURSE&lt;\/p&gt;&lt;p&gt;Type: Cells Less Than&lt;\/p&gt;&lt;p&gt;Derivative Option: Curvature&lt;\/p&gt;&lt;p&gt;Curvature of: Phases, volume fraction&lt;\/p&gt;&lt;p&gt;Phase: ethanol\/water or liquid oxygen&lt;\/p&gt;&lt;p&gt;Cells having value less than: 1e-14&lt;\/p&gt;&lt;p&gt;&lt;br&gt;CONTROLS&lt;\/p&gt;&lt;p&gt;Maximum refinement level: 3&lt;\/p&gt;&lt;p&gt;Min orthogonal quality: 0.2&lt;\/p&gt;&lt;p&gt;An expression is used to only refine cells in the main domain, not the injector elements&lt;\/p&gt;&lt;p&gt;Adaptive time stepping is used, with a global courant number of 0.9.&lt;\/p&gt;&lt;p&gt;&nbsp;&lt;\/p&gt;&lt;p&gt;The solution always errors out just after the iso surface enters the main domain and the adaptive meshing kicks in. The adaptive meshing works fine when evaporation is off though&lt;\/p&gt;&lt;p&gt;&nbsp;&lt;\/p&gt;&lt;p&gt;The mesh is initially very course due the the use of adaptive mesh refinement&lt;\/p&gt;&lt;p&gt;&lt;strong id=&#8221;docs-internal-guid-48e1ff5a-7fff-6a3d-97ac-17b47fe32054&#8243;&gt;<img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/innovationspace.ansys.com\/forum\/wp-content\/uploads\/sites\/2\/2026\/03\/08-03-2026-1773000364-blobid0.png\" width=\"624\" height=\"315\" \/>&lt;\/p&gt;&lt;p&gt; &lt;\/p&gt;&lt;p&gt;Here is what the residuals usually look like. The one of the gas species always seems to be having issues&lt;\/p&gt;&lt;p&gt;<img decoding=\"async\" src=\"https:\/\/innovationspace.ansys.com\/forum\/wp-content\/uploads\/sites\/2\/2026\/03\/08-03-2026-1773000499-mceclip0.png\" \/>&lt;\/p&gt;&lt;p&gt;&nbsp;&lt;\/p&gt;&lt;\/p&gt;&lt;\/p&gt;<\/p>\n","protected":false},"template":"","class_list":["post-453949","topic","type-topic","status-publish","hentry"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_forum_id":["27792"],"_bbp_topic_id":["453949"],"_bbp_author_ip":["2603:8001:72f0:75e0:a019:b10c:cbde:7f50"],"_bbp_last_reply_id":["454044"],"_bbp_last_active_id":["454044"],"_bbp_last_active_time":["2026-03-10 09:25:44"],"_bbp_reply_count":["3"],"_bbp_reply_count_hidden":["0"],"_bbp_voice_count":["2"],"_bbp_engagement":["343144","199"],"_btv_view_count":["56"],"_bbp_topic_status":["unanswered"],"_edit_last":["343144"],"_bbp_revision_log":["a:2:{i:453950;a:2:{s:6:\"author\";i:343144;s:6:\"reason\";s:0:\"\";}i:453951;a:2:{s:6:\"author\";i:343144;s:6:\"reason\";s:0:\"\";}}"],"_bbp_subscription":["199","343144"]},"test":"zwernjaydengmail-com"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/453949","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":2,"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/453949\/revisions"}],"predecessor-version":[{"id":453951,"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/453949\/revisions\/453951"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=453949"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}