{"id":34918,"date":"2019-04-24T20:25:38","date_gmt":"2019-04-24T20:25:38","guid":{"rendered":"\/forum\/forums\/topic\/preview-mesh-motion-negative-cell-volume\/"},"modified":"2019-04-24T20:25:38","modified_gmt":"2019-04-24T20:25:38","slug":"preview-mesh-motion-negative-cell-volume","status":"closed","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/preview-mesh-motion-negative-cell-volume\/","title":{"rendered":"Preview Mesh Motion- negative cell volume"},"content":{"rendered":"<p>Hi all,<\/p>\n<p><\/p>\n<p>&nbsp;<\/p>\n<p><\/p>\n<p>I am modeling a centrifugal pump using both an SST and k-epsilon model. The pump has an MRF (rotating fluid region) around the impeller and the impeller wall is moving relative to the MRF. When I preview mesh motion I am getting negative cell volume. I have tried decreasing the time step size to .0001 and nothing seems to work. I have also used body sizing in mesh to create the same sized cells in the MRF zone and adjacent deforming mesh.&nbsp;<span style=\"display: inline !important; float: none; background-color: #ffffff; color: #3b3b3b; font-family: Arial,Helvetica,sans-serif; font-size: 14px; font-style: normal; font-variant: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: left; text-decoration: none; text-indent: 0px; text-transform: none; -webkit-text-stroke-width: 0px; white-space: normal; word-spacing: 0px;\">Any suggestions? Below is the deforming mesh from my model and the mesh generated of the entire pump.<\/span><\/p>\n<p><\/p>\n<p><img decoding=\"async\" src=\"https:\/\/us.v-cdn.net\/6032193\/uploads\/attachments\/c3031470-aeb1-421a-9963-a9d20110c29d\/d9a1247c-9e3b-49d8-b13e-aa39014f6917_meshmotion2.jpg?width=690&amp;upscale=false\" alt=\"\"><img decoding=\"async\" src=\"https:\/\/us.v-cdn.net\/6032193\/uploads\/attachments\/c3031470-aeb1-421a-9963-a9d20110c29d\/6bbe0c02-b2ce-4492-a72d-aa3901509289_mesh2.jpg?width=690&amp;upscale=false\" alt=\"\"><\/p>\n<p><\/p>\n<p>&nbsp;<\/p>\n<p><\/p>\n<p><img decoding=\"async\" src=\"https:\/\/us.v-cdn.net\/6032193\/uploads\/attachments\/c3031470-aeb1-421a-9963-a9d20110c29d\/26770384-749a-4b1b-882f-aa39014f1344_meshmotion1.jpg?width=690&amp;upscale=false\" alt=\"\"><\/p>\n","protected":false},"template":"","class_list":["post-34918","topic","type-topic","status-closed","hentry"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_old_topic_id":["7090"],"_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"],"_btv_view_count":["227"],"_bbp_topic_status":["unanswered"],"_bbp_status":["publish"],"_bbp_topic_id":["34918"],"_bbp_forum_id":["27792"],"_bbp_engagement":["161689"],"_bbp_voice_count":["1"],"_bbp_reply_count":["0"],"_bbp_last_reply_id":["0"],"_bbp_last_active_id":["34918"],"_bbp_last_active_time":["2019-04-24 20:25:38"]},"test":"lianapolikaitis"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/34918","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\/34918\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=34918"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}