{"id":166969,"date":"2022-03-04T03:45:46","date_gmt":"2022-03-04T03:45:46","guid":{"rendered":"\/forum\/forums\/topic\/cfl-in-adaptive-time-step-definition-vs-max-cell-convective-courant-number\/"},"modified":"2022-03-09T13:21:55","modified_gmt":"2022-03-09T13:21:55","slug":"cfl-in-adaptive-time-step-definition-vs-max-cell-convective-courant-number","status":"closed","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/cfl-in-adaptive-time-step-definition-vs-max-cell-convective-courant-number\/","title":{"rendered":"CFL in adaptive time-step definition vs. max Cell Convective Courant number"},"content":{"rendered":"<div class=\"Item-Body\">\n<div class=\"Message userContent\">\n<p>Hi all,<\/p>\n<p><\/p>\n<\/p>\n<p>I am trying to use CFL based adaptive time-stepping to run an LES case to a statistically steady-state. I want to run this initial stage of the simulation at a &#039;high&#039; CFL number of ~5. To do that, I have turned on adaptive time-stepping feature on Fluent and proceeded to run the calculation. In the meantime, I also have a report-definition set-up to print out the maximum Cell Convective Courant number (under Reports\/Velocity\/Cell-convective Courant no). Interestingly, my Cell-convective courant number reading for the case is around 0.4 with adaptive time stepping on and CFL set to 5. <\/p>\n<p>I also tried rerunning the case with the adaptive time-stepping CFL setting set to 50 and my Cell-convective Courant no increased by factor of 10 to about 4. <\/p>\n<p><\/p>\n<\/p>\n<p>So my question is, what is the difference between the Cell-convective courant number and the CFL number that fluent calculates for it&#039;s adaptive time-stepping scheme? Are they the same or different? If they are the same, why is there a factor of 10 difference between my control parameter and my calculated parameter? <\/p>\n<p><\/p>\n<\/p>\n<p>Any clarification wrt this is highly appreciated. Thanks!<\/p>\n<p><\/p>\n<\/p>\n<p>Mana<\/p>\n","protected":false},"template":"","class_list":["post-166969","topic","type-topic","status-closed","hentry","topic-tag-ansys-fluent","topic-tag-cfl-time-step-1","topic-tag-courant-number","topic-tag-timestepsize","topic-tag-transient"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_btv_view_count":["3901"],"_bbp_likes_count":["0"],"_bbp_subscription":["253759"],"_bbp_topic_status":["unanswered"],"_bbp_status":["publish"],"_bbp_topic_id":["166969"],"_bbp_forum_id":["27792"],"_bbp_engagement":["25","179642"],"_bbp_voice_count":["2"],"_bbp_reply_count":["3"],"_bbp_last_reply_id":["207339"],"_bbp_last_active_id":["207339"],"_bbp_last_active_time":["2022-03-09 13:21:55"]},"test":"manahara8"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/166969","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\/166969\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=166969"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}