{"id":398594,"date":"2024-12-27T09:13:36","date_gmt":"2024-12-27T09:13:36","guid":{"rendered":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/transient-thermal-result-for-laser-annealing-solidgtgtliquidgtgtsolid\/"},"modified":"2024-12-27T13:30:49","modified_gmt":"2024-12-27T13:30:49","slug":"transient-thermal-result-for-laser-annealing-solidgtgtliquidgtgtsolid","status":"publish","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/transient-thermal-result-for-laser-annealing-solidgtgtliquidgtgtsolid\/","title":{"rendered":"transient thermal result for laser annealing (solid&gt;&gt;liquid&gt;&gt;solid)"},"content":{"rendered":"<p>&lt;p&gt;&lt;p&gt;&lt;p&gt;&lt;p&gt;&lt;p&gt;&lt;p&gt;Greeting all:&lt;\/p&gt;&lt;p&gt;I would like to know if my settings and assumptions for transient heat transfer are appropriate:&lt;\/p&gt;&lt;p&gt;1: For the upper heat convection region, does it need to have directionality?&lt;br&gt;In other modules in Workbench, I&rsquo;ve seen that the directionality of convection needs to be clearly defined (e.g., FLUENT, ICEPAK, etc.).&lt;br&gt;Currently, I have only set the magnitude of &lt;span class=&#8221;katex&#8221;&gt;&lt;span class=&#8221;katex-mathml&#8221;&gt;H&lt;\/span&gt;&lt;span class=&#8221;mord mathnormal&#8221;&gt;15&lt;\/span&gt;&lt;\/span&gt;, and it is a constant.&lt;br&gt;(My assumption is that air convection only occurs above the model.)&lt;\/p&gt;&lt;p&gt;<img decoding=\"async\" src=\"https:\/\/innovationspace.ansys.com\/forum\/wp-content\/uploads\/sites\/2\/2024\/12\/27-12-2024-1735290557-H.png\" alt=\"\" \/>&lt;\/p&gt;&lt;p&gt;2:During the annealing process, the metal undergoes a phase change from solid to liquid due to heating (with a brief two-phase transition in between), and after the laser stops, it cools down slowly (following Newton&rsquo;s cooling law). The metal transitions back from liquid to solid as it cools.&lt;br&gt;Do I need to define any additional settings for this phase transition between solid and liquid?&lt;br&gt;Currently, I have only set the melting point of the metal (a-Si melting point = 1414&deg;C).<img decoding=\"async\" src=\"https:\/\/innovationspace.ansys.com\/forum\/wp-content\/uploads\/sites\/2\/2024\/12\/27-12-2024-1735290608-pro.png\" alt=\"\" \/>&lt;\/p&gt;&lt;p&gt;I noticed that FLUENT has a &#8220;melting&#8221; feature, and I am unsure if I have chosen the wrong module (using FLUENT instead of Transient Thermal).&lt;\/p&gt;&lt;p&gt;If considering the phase change, I made a simple assumption shown in the diagram below:&lt;br&gt;The peak temperature will slightly decrease (the highest point of the red line) &nbsp;This case mainly focuses on the temperature of the a-Si metal layer on the surface, as it is directly exposed to laser light for annealing.&lt;\/p&gt;&lt;p&gt;<img decoding=\"async\" src=\"https:\/\/innovationspace.ansys.com\/forum\/wp-content\/uploads\/sites\/2\/2024\/12\/27-12-2024-1735290757-ques.jpg\" alt=\"\" \/>&lt;\/p&gt;&lt;p&gt; here&#8217;s the question, In FLUENT, can the heat flux only be a constant?&lt;\/p&gt;&lt;p&gt;Thank you!&lt;br&gt;If you have any suggestions, please let me know.&lt;\/p&gt;&lt;\/p&gt;&lt;\/p&gt;&lt;\/p&gt;&lt;\/p&gt;&lt;\/p&gt;<\/p>\n","protected":false},"template":"","class_list":["post-398594","topic","type-topic","status-publish","hentry","topic-tag-ansys-transient-thermal-2","topic-tag-melting-solidification-2"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_forum_id":["27791"],"_bbp_topic_id":["398594"],"_bbp_subscription":["23864","23687"],"_bbp_author_ip":["59.125.76.248"],"_bbp_last_reply_id":["403747"],"_bbp_last_active_id":["403747"],"_bbp_last_active_time":["2025-01-06 15:42:37"],"_bbp_reply_count":["3"],"_bbp_reply_count_hidden":["0"],"_bbp_voice_count":["2"],"_bbp_engagement":["23864","23687"],"_btv_view_count":["441"],"_bbp_topic_status":["unanswered"],"_edit_last":["23864"],"_bbp_revision_log":["a:5:{i:398595;a:2:{s:6:\"author\";i:23864;s:6:\"reason\";s:0:\"\";}i:398596;a:2:{s:6:\"author\";i:23864;s:6:\"reason\";s:0:\"\";}i:398597;a:2:{s:6:\"author\";i:23864;s:6:\"reason\";s:0:\"\";}i:398607;a:2:{s:6:\"author\";i:23864;s:6:\"reason\";s:0:\"\";}i:398609;a:2:{s:6:\"author\";i:23864;s:6:\"reason\";s:0:\"\";}}"]},"test":"n2390ngmail-com"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/398594","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":5,"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/398594\/revisions"}],"predecessor-version":[{"id":398609,"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/398594\/revisions\/398609"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=398594"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}