{"id":235722,"date":"2022-09-19T20:10:20","date_gmt":"2022-09-19T20:10:20","guid":{"rendered":"\/forum\/forums\/topic\/model-marangoni-effect-dependent-on-temperature-and-uds\/"},"modified":"2022-09-19T20:10:20","modified_gmt":"2022-09-19T20:10:20","slug":"model-marangoni-effect-dependent-on-temperature-and-uds","status":"closed","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/model-marangoni-effect-dependent-on-temperature-and-uds\/","title":{"rendered":"Model Marangoni effect – dependent on temperature and UDS"},"content":{"rendered":"

Hi, in my case the surface tension gradient is dependent on the temperature and a user-defined-scalar. i model this in two ways, <\/p>\n

    \n
  1. the first one is to use the built-in Marangoni stress in Wall Momentum panel. Use an expression of temperature and UDSI(0) to define the surface tension gradient. But the expression is not single-valued. A example is like this, 2.03*log(1.0+ UDS(uds = ‘uds-0’) * exp(StaticTemperature). So here the expression is limited to a single valued quantity?<\/li>\n
  2. the second is to use udf by coding the Marangoni stress = d(gamma)\/d(T)*d(T)\/d(x). I get the d(T)\/d(x) by the marco C_T_G. This method gives a much larger velocity than the built-in method in a test case (20 m\/s vs. 1 m\/s). in the test case, the d(gamma)\/d(T) = -5e-4. i suspect the built-in uses a differnt temperature gradient than that obtained by C_T_G. <\/li>\n<\/ol>\n

    I appreciate all the suggestions. <\/p>\n","protected":false},"template":"","class_list":["post-235722","topic","type-topic","status-closed","hentry"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_subscription":["261258","22555"],"_bbp_author_ip":["23.56.168.214"]," _bbp_last_reply_id":["0"]," _bbp_likes_count":["0"],"_btv_view_count":["1928"],"_bbp_topic_status":["unanswered"],"_bbp_status":["publish"],"_bbp_topic_id":["235722"],"_bbp_forum_id":["27792"],"_bbp_engagement":["22555","261258"],"_bbp_voice_count":["2"],"_bbp_reply_count":["7"],"_bbp_last_reply_id":["235904"],"_bbp_last_active_id":["235904"],"_bbp_last_active_time":["2022-09-21 15:53:48"]},"test":"gao-1571osu-edu"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/235722","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\/235722\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=235722"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}