{"id":159205,"date":"2021-06-06T07:50:57","date_gmt":"2021-06-06T07:50:57","guid":{"rendered":"\/forum\/forums\/topic\/y-calculations\/"},"modified":"2021-06-07T13:01:10","modified_gmt":"2021-06-07T13:01:10","slug":"y-calculations","status":"closed","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/y-calculations\/","title":{"rendered":"y+ Calculations"},"content":{"rendered":"<div class=\"Item-Body\">\n<div class=\"Message userContent\">\n<p>I have been trying to verify and compare my analytical and numerically predicted y+ values for turbulent fluid flow through a 2D backward-facing step problem (Re_hydraulic_diameter &asymp; 1e5) based on the wall modelling approach of using a wall function such that my first grid cell lies in the range: 30 &lt; y+ &lt; 300. Based on the formula provided in the ANSYS Customer Training Material for Lecture 6 Turbulence Modeling, released around December 2010, the calculation of first cell height is based on the normal distance from the wall, almost equal to twice the cell-centroid position, however, the same formula has been used in different calculators to estimate the near wall cell size based on the cell-centroid position. Mathematically, the difference in estimation of y+ calculations can be expressed below as: <\/p>\n<p>As per Lecture 6 Turbulence Modeling of ANSYS Customer Training Material: <\/p>\n<div class=\"embedExternal embedImage\">\n<div class=\"embedExternal-content\">\n<a class=\"embedImage-link\" href=\"\/forum\/wp-content\/uploads\/forum-uploads\/262\/9UXXOOJFIWX2.png\" rel=\"nofollow noopener\" target=\"_blank\"><br \/>\n<img decoding=\"async\" class=\"embedImage-img\" src=\"\/forum\/wp-content\/uploads\/forum-uploads\/262\/9UXXOOJFIWX2.png\" alt=\"image.png\" \/><br \/>\n<\/a><\/p>\n","protected":false},"template":"","class_list":["post-159205","topic","type-topic","status-closed","hentry","topic-tag-2d","topic-tag-ansys-fluent","topic-tag-fluid-flow","topic-tag-y-plus"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_author_ip":[""],"_bbp_old_reply_author_name_id":["Anonymous"],"_bbp_old_is_reply_anonymous_id":["false"],"_btv_view_count":["3122"],"_bbp_likes_count":["0"],"_bbp_topic_status":["unanswered"],"_bbp_status":["publish"],"_bbp_topic_id":["159205"],"_bbp_forum_id":["27792"],"_bbp_engagement":["25","191941"],"_bbp_voice_count":["2"],"_bbp_reply_count":["4"],"_bbp_last_reply_id":["181181"],"_bbp_last_active_id":["181181"],"_bbp_last_active_time":["2021-06-07 13:01:10"]},"test":"dipteshpawa1993gmail-com"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/159205","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\/159205\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=159205"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}