{"id":162101,"date":"2021-09-09T19:08:12","date_gmt":"2021-09-09T19:08:12","guid":{"rendered":"\/forum\/forums\/topic\/udf-mass-diffusivity-for-multicomponent-dij\/"},"modified":"2021-10-27T22:42:04","modified_gmt":"2021-10-27T22:42:04","slug":"udf-mass-diffusivity-for-multicomponent-dij","status":"closed","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/udf-mass-diffusivity-for-multicomponent-dij\/","title":{"rendered":"UDF mass diffusivity for multicomponent Dij"},"content":{"rendered":"<div class=\"Item-Body\">\n<div class=\"Message userContent\">\n<p>Hi, everyone <\/p>\n<p> I need to write the UDF for my multicomponent diffusivity (Dij) because my mass diffusivity is not only depend on temperature, so I used DEFINE_DIFFUSIVITY(myudf,c,t,i) . My multicomponent includes 4 species My question is:<\/p>\n<ol>\n<li>How to define the mass diffusivity of Dij ? I used if (i==0) , if(i==1), if(i==2), else to define i index . How about j ? Or do I need to use array to define Dij? For example <\/li>\n<\/ol>\n<p> diff[0][1]=10e-6;<\/p>\n<p> diff[0][2]=10e-6;<\/p>\n","protected":false},"template":"","class_list":["post-162101","topic","type-topic","status-closed","hentry"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_author_ip":[""],"_bbp_old_reply_author_name_id":["Anonymous"],"_bbp_old_is_reply_anonymous_id":["false"],"_btv_view_count":["379"],"_bbp_likes_count":["0"],"_bbp_subscription":["239130"],"_bbp_topic_status":["unanswered"],"_bbp_status":["publish"],"_bbp_topic_id":["162101"],"_bbp_forum_id":["27792"],"_bbp_engagement":["5120","199967"],"_bbp_voice_count":["2"],"_bbp_reply_count":["1"],"_bbp_last_reply_id":["191579"],"_bbp_last_active_id":["191579"],"_bbp_last_active_time":["2021-10-27 22:42:04"]},"test":"fai-chananungmail-com"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/162101","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\/162101\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=162101"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}