{"id":455247,"date":"2026-03-25T22:40:36","date_gmt":"2026-03-25T22:40:36","guid":{"rendered":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/turbulence-model-in-lsdyna-icfd\/"},"modified":"2026-03-25T22:40:36","modified_gmt":"2026-03-25T22:40:36","slug":"turbulence-model-in-lsdyna-icfd","status":"publish","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/turbulence-model-in-lsdyna-icfd\/","title":{"rendered":"Turbulence model in LSDYNA ICFD"},"content":{"rendered":"<p>&lt;p&gt;Hello, if possible, I like to confirm some basic understanding of ICFD turbulence models.&nbsp; &nbsp; &nbsp;To that end, I have a few questions, maybe basic but really appreciate your help:&lt;\/p&gt;&lt;p&gt;1) if I don&#8217;t use ICFD_control_turbulence or ICFD_Boundary_prescribe_turbulence in a ICFD model in LS-Dyna, does the solver still utilize some default turbulence model or is turbulence (say vortex shedding) completely turned off?&nbsp;&nbsp;&lt;\/p&gt;&lt;p&gt;2) I have a simple air flow though channel against a ball (spherical wall) problem and if I turn on ICFD_control_turbulence or ICFD_Boundary_Prescribe_turbulence, the solution simply hangs.&nbsp; &nbsp;I tried different boundary layers thickness\/growth in mesh_BL and looked at K-E and K-omega models and tried different inlet velocity conditions, but the solution simply hangs (seems to indicate divergence) and velocity reading is completely wrong.&nbsp;&lt;\/p&gt;&lt;p&gt;In fluent, this would have terminated the job but in Dyna, it seems to be going forever without terminating.&nbsp; &nbsp; is it possible to help me understand the general logic of what the ICFD solver is checking when we turn on turbulence models?&nbsp;&nbsp;&lt;\/p&gt;&lt;p&gt;I also appreciate any reading material on this topic.&nbsp; &nbsp;I&#8217;ve been looking at the basic problems and try to look at the fluent tutorials to try to redo them inside Dyna.&nbsp; &nbsp;My ultimate goal is to utilize LS-Dyna for strongly coupled FSI problems where even the simplest types of problems become impossible in system coupling between Fluent and Mechanical and that&#8217;s why Dyna becomes very advantageous.&nbsp;&lt;\/p&gt;&lt;p&gt;Thank you for your help.&nbsp;&lt;\/p&gt;<\/p>\n","protected":false},"template":"","class_list":["post-455247","topic","type-topic","status-publish","hentry"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_forum_id":["27814"],"_bbp_topic_id":["455247"],"_bbp_author_ip":["136.226.108.246"],"_bbp_last_reply_id":["0"],"_bbp_last_active_id":["455247"],"_bbp_last_active_time":["2026-03-25 22:40:36"],"_bbp_reply_count":["0"],"_bbp_reply_count_hidden":["0"],"_bbp_voice_count":["1"],"_bbp_engagement":["480261"],"_btv_view_count":["83"],"_bbp_topic_status":["unanswered"],"_edit_lock":["1774535574:199"]},"test":"64872acced255c930764e49420794aef51a32d56"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/455247","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\/455247\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=455247"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}