{"id":52235,"date":"2021-02-15T09:47:43","date_gmt":"2021-02-15T09:47:43","guid":{"rendered":"\/forum\/forums\/topic\/negative-cell-volume-alternative-solution\/"},"modified":"2021-02-15T09:47:43","modified_gmt":"2021-02-15T09:47:43","slug":"negative-cell-volume-alternative-solution","status":"closed","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/negative-cell-volume-alternative-solution\/","title":{"rendered":"Negative Cell Volume Alternative Solution"},"content":{"rendered":"
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Hi Community,<\/p>\n

I am doing a CFD analysis for my major project in Mechanical Engineering. <\/p>\n

I am supposed to improve a water driven motor that is build like a lobe pump. <\/p>\n

I want to simulate a 3D domain using Fluent. The first problem to deal with was the limit of mesh cells in the student version of Ansys, while providing an acceptable orthogonal quality and skewness. <\/p>\n

After adjusting the mesh, I ended up with 400k cells and a mesh quality which Fluent is not complaining about. <\/p>\n

I am using an UDF for defining the rotation of the rotors in dynamic mesh and applying<\/p>\n

the k-epsilon-model. I also set remeshing and smoothing.<\/p>\n

However, after every iteration Fluent is remeshing and the total amount of mesh cells slightly increases, until the mesh cell limit is exceeded. Then the calculation stops and Fluent ends.<\/p>\n

In the forum I read, that this issue can not be solved.<\/p>\n

So, to decrease the initial number of cells, I cut down the domain more and more ending up with the following mesh.<\/p>\n

 <\/p>\n

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\n\"oq
\n<\/a><\/p>\n","protected":false},"template":"","class_list":["post-52235","topic","type-topic","status-closed","hentry","topic-tag-dynamic-mesh","topic-tag-fluid-flow","topic-tag-negative-cell-volume","topic-tag-timestepsize"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_old_topic_id":["24521"],"_bbp_old_topic_author_name_id":["Anonymous"],"_bbp_old_is_topic_anonymous_id":["false"],"_bbp_old_closed_status_id":["publish"],"_bbp_author_ip":["Z?0?"],"_bbp_old_sticky_status_id":["normal"],"_bbp_likes_count":["0"],"_btv_view_count":["981"],"_bbp_topic_status":["unanswered"],"_bbp_status":["publish"],"_bbp_topic_id":["52235"],"_bbp_forum_id":["27792"],"_bbp_engagement":["25","184487","186116"],"_bbp_voice_count":["3"],"_bbp_reply_count":["8"],"_bbp_last_reply_id":["143158"],"_bbp_last_active_id":["143158"],"_bbp_last_active_time":["2021-02-21 15:31:59"]},"test":"haebi"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/52235","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\/52235\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=52235"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}