{"id":32949,"date":"2019-01-29T15:41:45","date_gmt":"2019-01-29T15:41:45","guid":{"rendered":"\/forum\/forums\/topic\/nita-slower-than-ita-in-fluent\/"},"modified":"2019-01-29T15:41:45","modified_gmt":"2019-01-29T15:41:45","slug":"nita-slower-than-ita-in-fluent","status":"closed","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/nita-slower-than-ita-in-fluent\/","title":{"rendered":"NITA slower than ITA in Fluent"},"content":{"rendered":"<p>I&#8217;m running an SBES simulation of a swirling flow in a pipe. Per the suggestion of Dr. Menter in &#8220;Best Practice: Scale-Resolving Simulations in ANSYS CFD, Ver. 2.00&#8221;, I tried out the Non-Iterative Time Advancement (NITA) scheme on my simulation since it should be significantly more CPU efficient than Iterative Time Advancement (ITA).<\/p>\n<p><\/p>\n<p>The results were a bit of a mixed bag, as the NITA (using either PISO or Fractional Step) was significantly slower per time step than&nbsp;ITA. NITA would take ~40s per timestep where as ITA would take ~15 seconds. However,&nbsp;NITA would converge in one time step and would have significantly&nbsp;lower residual values than ITA (around 2 orders of magnitude lower).<\/p>\n<p><\/p>\n<p>First question, are these expected\/normal results?<\/p>\n<p><\/p>\n<p>Second question, how might I go about speeding up the NITA?&nbsp;Like how to reduce the residual criteria for it (since it&#8217;s well lower than what I need)?<\/p>\n","protected":false},"template":"","class_list":["post-32949","topic","type-topic","status-closed","hentry"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_old_topic_id":["5121"],"_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","0","0","0"],"_btv_view_count":["1687"],"_edit_lock":["1675885591:4"],"_bbp_topic_status":["unanswered"],"_bbp_status":["publish"],"_bbp_topic_id":["32949"],"_bbp_forum_id":["27792"],"_bbp_engagement":["22555","158391"],"_bbp_voice_count":["2"],"_bbp_reply_count":["4"],"_bbp_last_reply_id":["76351"],"_bbp_last_active_id":["76351"],"_bbp_last_active_time":["2019-01-30 05:35:20"]},"test":"jameswright"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/32949","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\/32949\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=32949"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}