{"id":39524,"date":"2019-12-10T19:44:16","date_gmt":"2019-12-10T19:44:16","guid":{"rendered":"\/forum\/forums\/topic\/using-cfd-post-to-calculate-the-local-nusselt-number-on-the-surface-of-a-horizontal-cylinder\/"},"modified":"2019-12-10T19:44:16","modified_gmt":"2019-12-10T19:44:16","slug":"using-cfd-post-to-calculate-the-local-nusselt-number-on-the-surface-of-a-horizontal-cylinder","status":"closed","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/using-cfd-post-to-calculate-the-local-nusselt-number-on-the-surface-of-a-horizontal-cylinder\/","title":{"rendered":"Using CFD-Post to calculate the Local Nusselt number on the surface of a horizontal cylinder"},"content":{"rendered":"<p>Hello,&nbsp;<\/p>\n<p>I am currently solving the case of forced convection across a heated horizontal cylinder (with constant surface temperature conditions). I know the equation to calculate the local Nu= &#8211; dT\/dr (which is the temperature derivative along the normal vector to the cylinder surface). <br \/>I&nbsp;couldn&#8217;t calculate the&nbsp;temperature derivative by using the expression tab in CFD-Post, i put the expression as follows: &#8220;Temperature.Gradient R @cylinder wall &#8221; <br \/>but it gives me the following error: &#8220;The following unrecognized name was referenced: Temperature.Gradient R&#8221;<\/p>\n<p><\/p>\n<p>P.S. i identified another variable &#8220;R&#8221; and its expression is sqrt(X^2 +Y^2) and i created a polyline at the cylinder surface and named it &#8220;cylinder wall&#8221;<\/p>\n<p><\/p>\n<p>Thank you!<\/p>\n","protected":false},"template":"","class_list":["post-39524","topic","type-topic","status-closed","hentry"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_old_topic_id":["11703"],"_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":["1073"],"_bbp_subscription":["245724"],"_bbp_topic_status":["unanswered"],"_bbp_status":["publish"],"_bbp_topic_id":["39524"],"_bbp_forum_id":["27792"],"_bbp_engagement":["199","171386","184481"],"_bbp_voice_count":["3"],"_bbp_reply_count":["6"],"_bbp_last_reply_id":["136866"],"_bbp_last_active_id":["136866"],"_bbp_last_active_time":["2020-12-24 13:02:12"]},"test":"davidb7"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/39524","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\/39524\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=39524"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}