{"id":35101,"date":"2019-05-02T20:47:02","date_gmt":"2019-05-02T20:47:02","guid":{"rendered":"\/forum\/forums\/topic\/epsilon-the-only-fluctuating-residual\/"},"modified":"2019-05-02T20:47:02","modified_gmt":"2019-05-02T20:47:02","slug":"epsilon-the-only-fluctuating-residual","status":"closed","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/epsilon-the-only-fluctuating-residual\/","title":{"rendered":"Epsilon – the only fluctuating residual"},"content":{"rendered":"

Hi,<\/p>\n

<\/p>\n

I am Calculating a 2D fluid model (only Viscous model), and the residuals are as below, which it shows the epsilon is fluctuating.<\/p>\n

<\/p>\n

\"\"<\/p>\n

<\/p>\n

Information of the model<\/strong>:Reynolds stress model, Quadric Pressure-strain, standard wall functions, default model constants<\/p>\n

<\/p>\n

Solution methods:<\/strong> pressure-velocity: simple<\/p>\n

<\/p>\n

Gradient: Green-Gauss node based<\/p>\n

<\/p>\n

pressure: PRESTO!<\/p>\n

<\/p>\n

momentum and viscosity and Re-stresses: second order Upwind<\/p>\n

<\/p>\n

URFs:<\/p>\n

<\/p>\n

Pressure: 0,3,<\/p>\n

<\/p>\n

density: 0,5<\/p>\n

<\/p>\n

Body forces: 1<\/p>\n

<\/p>\n

Momentum: 0.6<\/p>\n

<\/p>\n

Swirl velocity: 0.8<\/p>\n

<\/p>\n

Turbulence kinetic energy, and, dissipation rate, and viscosity: 0.3<\/p>\n

<\/p>\n

(I have reduced the turbulent residuals from 0.8 to 0.3 to see the effect on fluctuation of epsilon, which did not have an effect of fluctuation)<\/p>\n

<\/p>\n

 <\/p>\n

<\/p>\n

The mesh is a refined mesh, with an average element quality of 0.92 (stnd.dev: 0.24) and orthogonal quality 0.99 (stnd.dev: 0.05).<\/p>\n

<\/p>\n

Do you have any suggestions for me to check the case and to improve the solution settings?<\/p>\n

<\/p>\n

Regards,<\/p>\n

<\/p>\n

Zari<\/p>\n

<\/p>\n

 <\/p>\n","protected":false},"template":"","class_list":["post-35101","topic","type-topic","status-closed","hentry"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_old_topic_id":["7273"],"_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"],"_btv_view_count":["1130"],"_bbp_subscription":["238500"],"_bbp_topic_status":["unanswered"],"_bbp_status":["publish"],"_bbp_topic_id":["35101"],"_bbp_forum_id":["27792"],"_bbp_engagement":["199","162071"],"_bbp_voice_count":["2"],"_bbp_reply_count":["1"],"_bbp_last_reply_id":["84387"],"_bbp_last_active_id":["84387"],"_bbp_last_active_time":["2019-05-03 11:18:20"]},"test":"zari"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/35101","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\/35101\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=35101"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}