{"id":244629,"date":"2022-12-21T12:46:24","date_gmt":"2022-12-21T12:46:24","guid":{"rendered":"\/forum\/forums\/topic\/creating-temperature-dependent-material-properties-with-expression-in-fluent\/"},"modified":"2022-12-21T12:46:24","modified_gmt":"2022-12-21T12:46:24","slug":"creating-temperature-dependent-material-properties-with-expression-in-fluent","status":"closed","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/creating-temperature-dependent-material-properties-with-expression-in-fluent\/","title":{"rendered":"Creating Temperature Dependent Material Properties with Expression in Fluent"},"content":{"rendered":"<p>Hello together,&nbsp;<\/p>\n<p>i am struggling to define the dynamic viscosity of my fluid in the material properties settings in Fluent.<br \/>I received the temperature dependent density and temperature dependent kinematic viscosity of a fluid. Both are given as a polynominal function. As i cannot enter the kinematic viscosity properties of the fluid directly, i want to create a new expression for the dynamic viscosity (Density*Kinematic Viscosity)<\/p>\n<p>The equation is as followed:<\/p>\n<p>(A0 [kg\/m^3] * StaticTemperature * StaticTemperature * 1 [K^-2] <br \/>+ A1 [kg\/m^3] * StaticTemperature * 1 [K^-1] <br \/>+ A2[kg\/m^3])<\/p>\n<p>*(B0 [m^2*s^-1]*StaticTemperature^6*1[K^-6] <br \/>&#8211; B1[m^2*s^-1]*StaticTemperature^5*1[K^-5] <br \/>+ B2[m^2*s^-1]*StaticTemperature^4*1[K^-4] <br \/>&#8211; B3 [m^2*s^-1]*StaticTemperature^3*1[K^-3] <br \/>+ B4 [m^2*s^-1]*StaticTemperature^2*1[K^-2] <br \/>&#8211; B5 [m^2*s^-1]*StaticTemperature*1[K^-1] <br \/>+ B6[m^2*s^-1])<\/p>\n<p>&nbsp;<\/p>\n<p>I Also tried to create a new named expression to define the kinematic vicosity with StaticTemperature as variable. But i always get the error &#8220;Expression is invalid in current model setup&#8221;<\/p>\n<p>I defined the density as a polynomial function already.<\/p>\n<p>I do not have a lot of experience in Fluent and hope one of you guys can help me out here.<\/p>\n<p>Thank you already!<\/p>\n","protected":false},"template":"","class_list":["post-244629","topic","type-topic","status-closed","hentry","topic-tag-expression","topic-tag-fluent","topic-tag-material-properties","topic-tag-udf","topic-tag-viscosity"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_subscription":["228332","15180"],"_bbp_author_ip":["23.192.164.18"]," _bbp_last_reply_id":["0"]," _bbp_likes_count":["0"],"_btv_view_count":["2758"],"_bbp_topic_status":["unanswered"],"_bbp_status":["publish"],"_bbp_topic_id":["244629"],"_bbp_forum_id":["27796"],"_bbp_engagement":["15180","228332"],"_bbp_voice_count":["2"],"_bbp_reply_count":["1"],"_bbp_last_reply_id":["244681"],"_bbp_last_active_id":["244681"],"_bbp_last_active_time":["2022-12-22 10:02:00"]},"test":"maurice-gonsergooglemail-com"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/244629","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\/244629\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=244629"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}