{"id":380840,"date":"2024-08-28T10:35:00","date_gmt":"2024-08-28T10:35:00","guid":{"rendered":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/evaporation-model-not-working-turbulent-viscosity-ratio-issue\/"},"modified":"2024-08-28T10:35:00","modified_gmt":"2024-08-28T10:35:00","slug":"evaporation-model-not-working-turbulent-viscosity-ratio-issue","status":"publish","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/evaporation-model-not-working-turbulent-viscosity-ratio-issue\/","title":{"rendered":"Evaporation Model not working. Turbulent Viscosity ratio issue."},"content":{"rendered":"<p>&lt;p&gt;Hello,&lt;\/p&gt;&lt;p&gt;I have been trying to model the evaporation of water inside a tube using the VOF model (Implicit, dispersed) and water as a material. Initially, I started doing with a 2D model of the tube which works fine in general, but as soon as I turned on multiphase modeling, I received two errors&nbsp;&lt;\/p&gt;&lt;p&gt;<strong>1- &#8220;turbulent viscosity limited to viscosity ratio of 1.000000e+05 in XXcells&#8221;&nbsp;<\/strong>and&lt;\/p&gt;&lt;p&gt;<strong>2- temperature limited to 5.000000e+03 in XXcells&nbsp;<\/strong>&lt;\/p&gt;&lt;p&gt;and continuity started to rise with every iteration until I received a floating error.&lt;\/p&gt;&lt;p&gt;I improved the mesh near the walls or increased the overall structured cell count, but the error persists.&nbsp;&lt;\/p&gt;&lt;p&gt;Then, I tried a smaller 3D tube as I had some experience with 3D phase change simulation.&nbsp;&lt;\/p&gt;&lt;p&gt;Initially, I used a tube with polyhedra meshing (0.015m dia inside &amp; 0.5m length) but the error persists regarding turbulent viscosity and temperature reached 5000K.&nbsp;&lt;\/p&gt;&lt;p&gt;Then, I meshed the geometry through ICEM to make a better structural mesh, but the error persists.&nbsp;&lt;\/p&gt;&lt;p&gt;&nbsp;&lt;\/p&gt;&lt;p&gt;<strong>Note:<\/strong> I have increased the turbulent viscosity limit, initialized with k = 1, and epsilon with 100, but it keeps on giving a floating error.&nbsp;&lt;\/p&gt;&lt;p&gt;One thing is that while using the SIMPLEC scheme, it diverges very quickly, but with PISO, it takes around 50 to 100 more iterations to diverge.&nbsp;&lt;\/p&gt;&lt;p&gt;&nbsp;&lt;\/p&gt;&lt;p&gt;Can you tell me what the possible error in this will be?&nbsp;&lt;\/p&gt;&lt;p&gt;Mass flow inlet = 13kg\/s,&nbsp;&lt;\/p&gt;&lt;p&gt;Turbulence = K-epsilon , realizable with enhanced wall treatment,&lt;\/p&gt;<\/p>\n","protected":false},"template":"","class_list":["post-380840","topic","type-topic","status-publish","hentry","topic-tag-condensation-evaporation-1","topic-tag-evaporation","topic-tag-ImplicitVOF-1","topic-tag-multiphase","topic-tag-multiphase-udf-evaporation-dpm-speciestransport-definesource-sourceterm-eulerian-lagrangian-1"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_subscription":["294380","199"],"_bbp_author_ip":["124.16.3.16"],"_btv_view_count":["244"],"_bbp_topic_status":["unanswered"],"_bbp_topic_id":["380840"],"_bbp_forum_id":["27792"],"_bbp_engagement":["199","294380"],"_bbp_voice_count":["2"],"_bbp_reply_count":["5"],"_bbp_last_reply_id":["381924"],"_bbp_last_active_id":["381924"],"_bbp_last_active_time":["2024-09-09 09:23:29"]},"test":"abdullahhassanmail-ustc-edu-cn"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/380840","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\/380840\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=380840"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}