{"id":29753,"date":"2018-07-20T20:29:28","date_gmt":"2018-07-20T20:29:28","guid":{"rendered":"\/forum\/forums\/topic\/how-to-pass-electric-current-magnitude-to-udf-for-deformation-calculation\/"},"modified":"2018-07-20T20:29:28","modified_gmt":"2018-07-20T20:29:28","slug":"how-to-pass-electric-current-magnitude-to-udf-for-deformation-calculation","status":"closed","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/how-to-pass-electric-current-magnitude-to-udf-for-deformation-calculation\/","title":{"rendered":"How to pass &#8220;Electric Current Magnitude&#8221; to UDF for deformation calculation?"},"content":{"rendered":"<p>I&#8217;m writing a UDF for galvanic corrosion deformation of Al and Cu block submerged in water.<\/p>\n<p><\/p>\n<p>The process goes like so:<\/p>\n<p><\/p>\n<p>1. the geometry is a 10mm*20mm*5mm electrolyte domain with one face split to 2 10mm square face representing boundary to Al and Cu electrode.<\/p>\n<p><\/p>\n<p>2. material is water-liquid for the entire domain with electric conductivity of 50 S\/m.<\/p>\n<p><\/p>\n<p>3. potential boundary conditions are set to galvanic potential of Al and Cu at -0.85 V and -0.3 V respectively&nbsp;<\/p>\n<p><\/p>\n<p>4. using fluent&#8217;s electric potential model, run steady state simulation<\/p>\n<p><\/p>\n<p>5. contour of&nbsp;Electric Current Magnitude is plotted as follow<\/p>\n<p><\/p>\n<p>&nbsp;<\/p>\n<p><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/us.v-cdn.net\/6032193\/uploads\/attachments\/0d2bbfc7-ea85-4f25-a582-a92301489781\/a0c453a6-d573-404b-976e-a923014a2e54_2018-07-17-12-14-20.jpg?width=690&amp;upscale=false\" alt=\"\" width=\"514\" height=\"173\"><\/p>\n<p><\/p>\n<p>6. I would&nbsp;then pass calculated &#8220;Electric Current Magnitude&#8221; as J to corrosion damage UDF to calculate corrosion rate in transient simulation and hook it to Dynamic mesh zone of Al electrode as mesh motion UDF<\/p>\n<p><\/p>\n<p>My question is how to pass the current density (or&nbsp;Electric Current Magnitude, a post-processing variable under potential) to UDF. I know there are micros that can pass cell or face&nbsp;variable like temperature and pressure to UDF like C_P(c,t) or F_T(f,t), but I can find no such macro for current density. Perhaps the potential model is still relatively new and incomplete? Is there anyway to work around that using UDM or RP variable?<\/p>\n<p><\/p>\n<p>Thanks in advance!<\/p>\n<p><\/p>\n<p>Paul Lee<\/p>\n<p><\/p>\n<p>P.S.&nbsp;attached is the UDF I have so far.<\/p>\n","protected":false},"template":"","class_list":["post-29753","topic","type-topic","status-closed","hentry"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_old_topic_id":["1922"],"_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","0","0","0","0"],"_btv_view_count":["2533"],"_bbp_topic_status":["unanswered"],"_bbp_status":["publish"],"_bbp_topic_id":["29753"],"_bbp_forum_id":["27792"],"_bbp_engagement":["4948","22555","157272","157910"],"_bbp_voice_count":["4"],"_bbp_reply_count":["6"],"_bbp_last_reply_id":["64138"],"_bbp_last_active_id":["64138"],"_bbp_last_active_time":["2018-09-14 00:05:48"]},"test":"paoching"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/29753","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\/29753\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=29753"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}