{"id":456613,"date":"2026-04-17T11:16:59","date_gmt":"2026-04-17T11:16:59","guid":{"rendered":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/which-fluent-boundary-condition-can-impose-temperature-and-radial-velocity\/"},"modified":"2026-04-17T11:16:59","modified_gmt":"2026-04-17T11:16:59","slug":"which-fluent-boundary-condition-can-impose-temperature-and-radial-velocity","status":"publish","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/which-fluent-boundary-condition-can-impose-temperature-and-radial-velocity\/","title":{"rendered":"Which Fluent boundary condition can impose temperature and radial velocity?"},"content":{"rendered":"

<p data-start=”251″ data-end=”271″>Hello,<\/p><p data-start=”273″ data-end=”382″>I am trying to understand how the  interface was likely implemented in Fluent in a 2D-axisymetrical heat pipe model.<\/p><p data-start=”384″ data-end=”445″>In the paper, the authors define at the  interface:<\/p><ul data-start=”447″ data-end=”624″><li data-section-id=”1waxuum” data-start=”447″ data-end=”477″>an <strong data-start=”452″ data-end=”477″>interface temperature<\/strong><\/li>\n

<li data-section-id=”1k1rc2c” data-start=”478″ data-end=”532″>a <strong data-start=”482″ data-end=”501″>radial velocity<\/strong> at  the interface<\/li>\n

<li data-section-id=”1eukef5″ data-start=”533″ data-end=”624″>and at the same time <strong data-start=”556″ data-end=”607″>heat transfer \/ heat flux through the interface<\/strong> must be possible<br><br><\/li>\n<\/ul>\n

<p data-start=”626″ data-end=”641″>My question is:<\/p><p data-start=”643″ data-end=”732″><strong data-start=”643″ data-end=”732″>Which type of boundary condition in ANSYS Fluent could be used for such an interface?<\/strong><\/p><p data-start=”734″ data-end=”809″>More specifically, I am looking for a boundary type that would allow me to:<\/p><\/p>\n

    <li data-section-id=”lydic2″ data-start=”811″ data-end=”884″>prescribe or update the <strong data-start=”838″ data-end=”853″>temperature<\/strong> at the  interface,<\/li>\n

    <li data-section-id=”tj8uoz” data-start=”885″ data-end=”972″>prescribe the <strong data-start=”902″ data-end=”928″>radial\/normal velocity<\/strong> associated with evaporation\/condensation,<\/li>\n

    <li data-section-id=”asbfgf” data-start=”973″ data-end=”1025″>still allow <strong data-start=”988″ data-end=”1022″>heat flux across the interface<\/strong>,<\/li>\n

    <li data-section-id=”uf41tl” data-start=”1026″ data-end=”1128″>and ideally apply this  in a 2D axisymmetric model.<\/li>\n<\/ol>\n

    <p data-start=”1130″ data-end=”1368″>A standard <strong data-start=”1141″ data-end=”1149″>wall<\/strong> seems problematic because it blocks mass transfer.<br data-start=”1200″ data-end=”1203″>A standard <strong data-start=”1214″ data-end=”1236″>interior\/interface<\/strong> seems problematic because I do not see how to directly impose both temperature and radial velocity there.<br data-start=”1342″ data-end=”1345″>So I would like to ask:<\/p><p data-start=”1370″ data-end=”1605″><strong data-start=”1370″ data-end=”1605″>Did the authors most likely use two separate boundary zones (for example velocity inlet \/ outlet type boundaries with UDFs), or is there another Fluent boundary condition better suited for this kind of coupled wick–vapor interface?<\/strong><\/p><p data-start=”1607″ data-end=”1633″>I am attaching two images:<\/p><ul data-start=”1634″ data-end=”1773″><li data-section-id=”1sv71ux” data-start=”1634″ data-end=”1705″>one showing the geometry and the location of the  interface<\/li>\n

    <li data-section-id=”ieemz9″ data-start=”1706″ data-end=”1773″>one showing the mesh and the corresponding interface in the paper<\/li>\n<\/ul>\n

    <p data-start=”1775″ data-end=”1897″>Any clarification on which Fluent boundary type is physically and numerically most appropriate here would be very helpful.<\/p><p data-start=”1899″ data-end=”1909″>Thank you.<\/p><\/p>\n","protected":false},"template":"","class_list":["post-456613","topic","type-topic","status-publish","hentry","topic-tag-2d-heat-transfer-2","topic-tag-boundary-condition","topic-tag-geometryinterface-1","topic-tag-interface-boundary"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_forum_id":["27792"],"_bbp_topic_id":["456613"],"_bbp_author_ip":["130.206.158.178"],"_bbp_last_reply_id":["456618"],"_bbp_last_active_id":["456618"],"_bbp_last_active_time":["2026-04-17 13:03:51"],"_bbp_reply_count":["1"],"_bbp_reply_count_hidden":["0"],"_bbp_voice_count":["2"],"_bbp_engagement":["677148","199"],"_btv_view_count":["33"],"_bbp_topic_status":["unanswered"],"_bbp_subscription":["199"]},"test":"philippgeorgiou6gmail-com"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/456613","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\/456613\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=456613"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}