{"id":33850,"date":"2019-03-11T09:57:52","date_gmt":"2019-03-11T09:57:52","guid":{"rendered":"\/forum\/forums\/topic\/compressible-liquid-density\/"},"modified":"2019-03-11T09:57:52","modified_gmt":"2019-03-11T09:57:52","slug":"compressible-liquid-density","status":"closed","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/compressible-liquid-density\/","title":{"rendered":"Compressible Liquid &#8211; Density"},"content":{"rendered":"<p>Hi,<\/p>\n<p><\/p>\n<p>I&acute;m dealing with a simulation considering the compression of the liquid. In Fluent, I can&acute;t set a value of the Bulk Modulus depending on the pressure.<\/p>\n<p><\/p>\n<p><img decoding=\"async\" src=\"https:\/\/us.v-cdn.net\/6032193\/uploads\/attachments\/d652d665-7f9c-42a4-8f4c-a96d00d34316\/199fa9df-1d0f-402c-a50c-aa0d00a3cc47_compress.jpg?width=690&amp;upscale=false\" alt=\"\"><\/p>\n<p><\/p>\n<p>Nevertheless, I can use &#8220;User defined&#8221; instead of &#8220;compressible liquid&#8221; in order to consider the density as function of pressure. I have found this (https:\/\/www.cfd-online.com\/Forums\/star-ccm\/73840-user-defined-density.html)<\/p>\n<p><\/p>\n<p><img decoding=\"async\" src=\"https:\/\/us.v-cdn.net\/6032193\/uploads\/attachments\/d652d665-7f9c-42a4-8f4c-a96d00d34316\/db85cf56-f285-40d8-b4f3-aa0d00a431a0_dens.jpg?width=690&amp;upscale=false\" alt=\"\"><\/p>\n<p><\/p>\n<p>Instead of the pressure at inlet, I want to use the pressure inside the domain. Should the following UDF work?&nbsp;<\/p>\n<p><\/p>\n<p><img decoding=\"async\" src=\"https:\/\/us.v-cdn.net\/6032193\/uploads\/attachments\/d652d665-7f9c-42a4-8f4c-a96d00d34316\/d6340d28-4c4f-492b-bcb5-aa0d00b4b7e7_rho.jpg?width=690&amp;upscale=false\" alt=\"\"><\/p>\n<p><\/p>\n<p>When I tried to compile this UDF, I have this error:<\/p>\n<p><\/p>\n<p><img decoding=\"async\" src=\"https:\/\/us.v-cdn.net\/6032193\/uploads\/attachments\/d652d665-7f9c-42a4-8f4c-a96d00d34316\/0856a010-943a-49b4-aba2-aa0d00b6d76f_fe.jpg?width=690&amp;upscale=false\" alt=\"\"><\/p>\n<p><\/p>\n<p>It is because of this (Exemple 4 &#8211; https:\/\/www.sharcnet.ca\/Software\/Fluent6\/html\/udf\/node43.htm), i.e. I have to include a speed of sound function too?<\/p>\n<p><\/p>\n<p>With a such function, are the density set as a different value at each cells depending on the pressure?<\/p>\n<p><\/p>\n<p>&nbsp;<\/p>\n<p><\/p>\n<p>Regards,<\/p>\n<p><\/p>\n<p>Maxime<\/p>\n<p><\/p>\n<p>&nbsp;<\/p>\n","protected":false},"template":"","class_list":["post-33850","topic","type-topic","status-closed","hentry"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_old_topic_id":["6022"],"_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":["3927"],"_bbp_subscription":["237203"],"_bbp_topic_status":["unanswered"],"_bbp_status":["publish"],"_bbp_topic_id":["33850"],"_bbp_forum_id":["27792"],"_bbp_engagement":["199","22555","159144"],"_bbp_voice_count":["3"],"_bbp_reply_count":["7"],"_bbp_last_reply_id":["80079"],"_bbp_last_active_id":["80079"],"_bbp_last_active_time":["2019-03-11 15:28:41"]},"test":"max4"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/33850","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\/33850\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=33850"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}