{"id":44265,"date":"2020-05-22T03:57:14","date_gmt":"2020-05-22T03:57:14","guid":{"rendered":"\/forum\/forums\/topic\/uds-for-heat-transfer-enthalpy-method\/"},"modified":"2020-05-22T03:57:14","modified_gmt":"2020-05-22T03:57:14","slug":"uds-for-heat-transfer-enthalpy-method","status":"closed","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/uds-for-heat-transfer-enthalpy-method\/","title":{"rendered":"UDS for heat transfer (enthalpy method)"},"content":{"rendered":"<p class=\"MsoNormal\">Hi,<\/p>\n<p><\/p>\n<p class=\"MsoNormal\">I want to model freezing of water in a solid matrix via ANSYS Fluent for which I have to use UDS. How can I define a UDS to solve the freezing problem with the enthalpy method? The Cp method is easy to set up, but it diverges as it approaches the freezing point.<\/p>\n<p><\/p>\n<p class=\"MsoNormal\" style=\"text-align: justify;\">&nbsp;Attached&nbsp;is the <strong>unsteady term<\/strong> for the cp method which actually stands for dT\/dt and is pretty much like Fluent manual suggests.<\/p>\n<p><\/p>\n<p class=\"MsoNormal\" style=\"text-align: justify;\">&nbsp;The enthalpy method is more consistent and seems to smoothly pass the phase change area, but I don&rsquo;t know how to define the scalar for the unsteady term. Because the unsteady term is dh\/dt, but the diffusion term is <span style=\"mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin;\">&alpha;<\/span>d<sup>2<\/sup>T\/dt<sup>2<\/sup>. The left-hand side is solving for the enthalpy (including both sensible and latent heats) and the right-hand side for the temperature. <strong>How can I relate enthalpy to temperature in the unsteady term?<\/strong><\/p>\n<p><\/p>\n<p class=\"MsoNormal\" style=\"text-align: justify;\">&nbsp;Kind Regards,<\/p>\n<p><\/p>\n<p class=\"MsoNormal\" style=\"text-align: justify;\">MHMD<\/p>\n","protected":false},"template":"","class_list":["post-44265","topic","type-topic","status-closed","hentry"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_old_topic_id":["16446"],"_bbp_old_topic_author_name_id":["Anonymous"],"_bbp_old_is_topic_anonymous_id":["false"],"_bbp_old_closed_status_id":["publish"],"_bbp_author_ip":[null],"_bbp_old_sticky_status_id":["normal"],"_bbp_likes_count":["0"],"_btv_view_count":["445"],"_bbp_subscription":["250585"],"_bbp_topic_status":["unanswered"],"_bbp_status":["publish"],"_bbp_topic_id":["44265"],"_bbp_forum_id":["27792"],"_bbp_engagement":["22555","176421"],"_bbp_voice_count":["2"],"_bbp_reply_count":["3"],"_bbp_last_reply_id":["115356"],"_bbp_last_active_id":["115356"],"_bbp_last_active_time":["2020-05-22 09:02:08"]},"test":"mhmd90"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/44265","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\/44265\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=44265"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}