{"id":166075,"date":"2023-03-17T13:10:58","date_gmt":"2023-03-17T13:10:58","guid":{"rendered":"\/knowledge\/forums\/topic\/for-flows-with-volumetric-forces-like-gravity-with-temperature-dependent-density-velocity-shows-unphysical-behavior-at-walls-vectors-are-pointing-outwards-through-the-wall-why\/"},"modified":"2023-07-31T12:27:16","modified_gmt":"2023-07-31T12:27:16","slug":"for-flows-with-volumetric-forces-like-gravity-with-temperature-dependent-density-velocity-shows-unphysical-behavior-at-walls-vectors-are-pointing-outwards-through-the-wall-why","status":"publish","type":"topic","link":"https:\/\/innovationspace.ansys.com\/knowledge\/forums\/topic\/for-flows-with-volumetric-forces-like-gravity-with-temperature-dependent-density-velocity-shows-unphysical-behavior-at-walls-vectors-are-pointing-outwards-through-the-wall-why\/","title":{"rendered":"For flows with volumetric forces (like gravity with temperature dependent density) velocity shows unphysical behavior at walls &#8211; vectors are pointing outwards through the wall, why?"},"content":{"rendered":"<p>The standard scheme for spatial discretization is &#8220;second order&#8221; or &#8220;standard&#8221; (in older versions). These scheme is not appropriate for flows with e. g. natural convection (buoyancy driven flow). It can lead to vectors pointing through the upper walls instead of a flow parallel to the wall (see attached picture 2039992_Second_Order_Vectors.jpg in the upper left and right corner). Use PRESTO or Body Force Weighted instead (see 2039992_PRESTO_Vectors.jpg and 2039992_BFW_Vectors.jpg).  WB project is also attached. <\/p>\n<p>Attachments:<br \/>\n1. <a href=https:\/\/ansys13.ansys.com\/KnowledgeArticles\/Phase-1\/2039992\/2039992.zip>2039992.zip<\/a><br \/>\n2. <a href= https:\/\/ansys13.ansys.com\/KnowledgeArticles\/Phase-1\/2039992\/2039992_BFW_Vectors.jpg>2039992_BFW_Vectors.jpg<\/a><br \/>\n3. <a href= https:\/\/ansys13.ansys.com\/KnowledgeArticles\/Phase-1\/2039992\/2039992_PRESTO_Vectors.jpg>2039992_PRESTO_Vectors.jpg<\/a><br \/>\n4. <a href= https:\/\/ansys13.ansys.com\/KnowledgeArticles\/Phase-1\/2039992\/2039992_Second_Order_Vectors.jpg>2039992_Second_Order_Vectors.jpg<\/a><\/p>\n","protected":false},"template":"","class_list":["post-166075","topic","type-topic","status-publish","hentry","topic-tag-16-1","topic-tag-fluent","topic-tag-fluid-dynamics","topic-tag-general","topic-tag-general-fluent","topic-tag-heattransfer"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_wp_page_template":["default"],"_bbp_last_active_time":["3-15-2023  20:20:11"],"_bbp_forum_id":["27796"],"_bbp_author_ip":["23.56.168.180"],"_btv_view_count":["436"],"siebel_km_number":["2039992"],"product_version":["16.1"],"km_published_date":["2015-08-11T13:52:26.000Z"],"family":["Fluid Dynamics"],"application_name":["FLUENT"]},"test":"solution"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/knowledge\/wp-json\/wp\/v2\/topics\/166075","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/innovationspace.ansys.com\/knowledge\/wp-json\/wp\/v2\/topics"}],"about":[{"href":"https:\/\/innovationspace.ansys.com\/knowledge\/wp-json\/wp\/v2\/types\/topic"}],"version-history":[{"count":0,"href":"https:\/\/innovationspace.ansys.com\/knowledge\/wp-json\/wp\/v2\/topics\/166075\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/knowledge\/wp-json\/wp\/v2\/media?parent=166075"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}