{"id":278521,"date":"2023-04-08T13:12:39","date_gmt":"2023-04-08T13:12:39","guid":{"rendered":"\/forum\/forums\/topic\/residual-fluctuations-and-inconsistent-lift-and-drag-coefficients-in-fluent\/"},"modified":"2023-04-08T15:16:16","modified_gmt":"2023-04-08T15:16:16","slug":"residual-fluctuations-and-inconsistent-lift-and-drag-coefficients-in-fluent","status":"closed","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/residual-fluctuations-and-inconsistent-lift-and-drag-coefficients-in-fluent\/","title":{"rendered":"Residual fluctuations and inconsistent lift and drag coefficients in Fluent"},"content":{"rendered":"

Hello all,<\/p>\n

I am conducting an analysis in Fluent software, focusing on flow separation at different angles of attack, such as 6 and 10 degrees. However, I have noticed that the residual values display fluctuating characteristics and the lift and drag coefficients do not converge to a certain value. I have attached an image showing the velocity vectors at 4, 6, and 10 degrees and residuals at 6 degrees for reference. For 4 degrees, I have converged results because there is nearly no separation. But when it separates, residuals start to oscillate shown in the image below. <\/p>\n

To obtain a more accurate analysis, I am seeking guidance on how to approach this issue. I have tried reducing the velocity at 6 degrees to decrease the flow separation and subsequently decrease the residual values, resulting in a slight convergence of the lift and drag coefficients. However, my analysis involves a Mach number around 0.8, and I am currently using the kw-SST method.<\/p>\n

I would greatly appreciate any suggestions or solutions that you may have regarding this problem. Thank you in advance for your assistance.<\/p>\n

Best regards,<\/p>\n

\"\"<\/a><\/p>\n

\"\"<\/a><\/p>\n","protected":false},"template":"","class_list":["post-278521","topic","type-topic","status-closed","hentry","topic-tag-ansys-cfd-1","topic-tag-convergence","topic-tag-flow-separation"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_subscription":["157005","13659","199"],"_bbp_author_ip":["23.56.168.190"]," _bbp_last_reply_id":["0"]," _bbp_likes_count":["0"],"_btv_view_count":["2152"],"_edit_lock":["1680966861:41269"],"_bbp_topic_status":["unanswered"],"_bbp_status":["publish"],"_bbp_topic_id":["278521"],"_bbp_forum_id":["27792"],"_bbp_engagement":["199","13659","157005"],"_bbp_voice_count":["3"],"_bbp_reply_count":["4"],"_bbp_last_reply_id":["278818"],"_bbp_last_active_id":["278818"],"_bbp_last_active_time":["2023-04-11 10:03:19"]},"test":"goktug-yilmaz"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/278521","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\/278521\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=278521"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}