{"id":243727,"date":"2022-12-12T09:15:53","date_gmt":"2022-12-12T09:15:53","guid":{"rendered":"\/forum\/forums\/topic\/negative-heat-flux-and-heat-transfer-coefficient-at-a-surface\/"},"modified":"2022-12-12T09:15:53","modified_gmt":"2022-12-12T09:15:53","slug":"negative-heat-flux-and-heat-transfer-coefficient-at-a-surface","status":"closed","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/negative-heat-flux-and-heat-transfer-coefficient-at-a-surface\/","title":{"rendered":"Negative heat flux and heat transfer coefficient at a surface !"},"content":{"rendered":"<p>Hello,<\/p>\n<p>I am simulating conjugate heat transfer in a nuclear fuel pin. Heat is generated in the fuel pellet and transferred to the liquid. I got the converged result. Now I want to calculate the heat transfer coefficient and heat flux at the cladding outside surface which is in contact with liquid. While I tried to get the surface heat transfer coefficient, I see the heat transfer coefficient was negative. I set the reference temperature of 566.25K where the inlet temperature is also 566.25K. The bulk temperature of the liquid increased to 612.25K at the outlet.&nbsp;<\/p>\n<p>HTC is dependent on the reference value. So, what should be the reference for this reference temp?&nbsp;<\/p>\n<p>What may be the reason for getting the negative value of&nbsp; HTC and total heat flux even though the surface temperature is always greater than the bulk\/inlet temperature?<\/p>\n<p>Is there any other way to get heat transfer and HTC? I am using a k-epsilon model with a wall function for turbulence modeling.<\/p>\n<p>Regards,<\/p>\n<p>Anadi<\/p>\n<p><img decoding=\"async\" src=\"\/forum\/wp-content\/uploads\/sites\/2\/2022\/12\/12-12-2022-1670836364-p3.PNG\" alt=\"\"><\/p>\n","protected":false},"template":"","class_list":["post-243727","topic","type-topic","status-closed","hentry","topic-tag-htc-2","topic-tag-heat-transfer-coefficient"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_subscription":["185601","22555"],"_bbp_author_ip":["23.192.164.14"]," _bbp_last_reply_id":["0"]," _bbp_likes_count":["0"],"_btv_view_count":["1580"],"_bbp_topic_status":["unanswered"],"_bbp_status":["publish"],"_bbp_topic_id":["243727"],"_bbp_forum_id":["27792"],"_bbp_engagement":["22555","185601"],"_bbp_voice_count":["2"],"_bbp_reply_count":["1"],"_bbp_last_reply_id":["243735"],"_bbp_last_active_id":["243735"],"_bbp_last_active_time":["2022-12-12 10:45:05"]},"test":"anadi"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/243727","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\/243727\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=243727"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}