I am running a simulation of a car using fluent 19.1. the mesh has been generated with a polyhexcore scheme and the baseline works well with the SIMPLEC solving scheme and the k-e turbulence model. I get the issue that the ‘turbulent viscosity ratio is limited to 1e+05’ in xxx cells but this disappears after a few hundred iterations.<\/p>\n
<\/p>\n
The issue I’m having however is that when I add a front splitter, the turbulent intensity stays limited in a few cells and the residuals of k and e however around 4e-02. I haven’t had this issue with the rearwing or the sideskirts I have added. I have tried increasing the under relaxation of k and e and ensured that my yplus doesn’t go below 30, however I get the same thing during solve, the residuals of k and e drop to 1e-04 before abruptly jumping to 1e-01.<\/p>\n
<\/p>\n
I have read that using a coupled solver can help this and have given it a go, it appears to have solved the issue, however I am unsure about the impact this will have on the accuracy of the simulation as coupled solvers are usually used for compressible problems. Does anyone know of any reason why using a coupled solver for this case is fundamentally a bad idea and if it is does anyone have suggestions for how to solve the issue I’m having with the segregated solver.<\/p>\n
<\/p>\n
<\/p>\n
<\/p>\n
I have attached an image of my mesh, I’m fairly happy with its quality and don’t think that this is causing the problem.<\/p>\n
<\/p>\n
<\/p>\n
<\/p>\n
Kind Regards <\/p>\n
<\/p>\n
<\/p>\n
<\/p>\n
Rikesh Mistry<\/p>\n","protected":false},"template":"","class_list":["post-31813","topic","type-topic","status-closed","hentry"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_old_topic_id":["3985"],"_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":["2893"],"_bbp_subscription":["237430"],"_bbp_topic_status":["unanswered"],"_bbp_status":["publish"],"_bbp_topic_id":["31813"],"_bbp_forum_id":["27792"],"_bbp_engagement":["22555","159588"],"_bbp_voice_count":["2"],"_bbp_reply_count":["3"],"_bbp_last_reply_id":["71594"],"_bbp_last_active_id":["71594"],"_bbp_last_active_time":["2018-12-06 12:03:36"]},"test":"rm19g14"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/31813","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\/31813\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=31813"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}