{"id":398698,"date":"2024-12-29T12:52:18","date_gmt":"2024-12-29T12:52:18","guid":{"rendered":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/residual-upset-for-melting-simulation\/"},"modified":"2024-12-29T12:52:18","modified_gmt":"2024-12-29T12:52:18","slug":"residual-upset-for-melting-simulation","status":"publish","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/residual-upset-for-melting-simulation\/","title":{"rendered":"Residual upset for melting simulation"},"content":{"rendered":"

<p>Hello Everyone,<\/p><p>I am trying to simulate the melting behavior of a homogeneous material inside a furnace (which is also simulated). This simulation is transient and in Ansys Fluent<\/p><p>At one or multiple times during the simulation the residuals of continuity and energy drastically increase (see picture) but the simulation does not diverge. This usually happens, when the melt fraction would achieve 100% at any point for the first time. Up until then, the temperature and melt distribution looks reasonable but during the upset, temperature is redistributed homogeneously in the melt regime (see before and after pictures of melt fraction and temperature).<\/p><p>The mesh is developed to ensure high enough resolutions within the thermal boundary layers and is 2D but rotational symmetric. Some of the important solver settings are depicted below. Also, material properties are partially defined as smooth, named expressions as this was identified as crucial for better convergence. The melt flow is expected to be laminar and the respective model is chosen. Energy and solidification\/melting is turned on (Mushy zone 10^8) and in the S2S model, all surfaces are included in the calculation for now.<\/p><p>Somehow, the pressure also reaches drastically high or low values ( +\/-10^34) and changes during the mentioned upsets. However, the vacuum is modeled as regular air and patched to 1 Pa, which does not show any effects.<\/p><p>Reducing the timestep from 0.5 s to 0.1 s did also not help. Lowering the energy relaxation factor helped in some cases but led to unreasonable high melting times.<\/p><p>What other possible solutions might i try or where might thes upsets originate from?<\/p><p>Residual upset<\/p><p>\"\"<\/p><p>Temperature distribution before upset<\/p><p>\"\"<\/p><p>Temperature distribution after upset<\/p><p>\"\"<\/p><p>Liquid fraction before upset (red portion is air, melt regime bottom middle that started melting)<\/p><p>\"\"<\/p><p>Melt fraction after upset (none)<\/p><p>\"\"<\/p><p>\"\"<\/p><p>\"\"<\/p><\/p>\n","protected":false},"template":"","class_list":["post-398698","topic","type-topic","status-publish","hentry"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_forum_id":["27792"],"_bbp_topic_id":["398698"],"_bbp_subscription":["465044","199"],"_bbp_author_ip":["2a02:3100:b1b4:9700:163:c40b:e3cb:b58"],"_bbp_last_reply_id":["403774"],"_bbp_last_active_id":["403774"],"_bbp_last_active_time":["2025-01-06 17:43:59"],"_bbp_reply_count":["6"],"_bbp_reply_count_hidden":["0"],"_bbp_voice_count":["2"],"_bbp_engagement":["465044","199"],"_btv_view_count":["198"],"_bbp_topic_status":["unanswered"]},"test":"flo-schustertum-de"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/398698","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\/398698\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=398698"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}