{"id":395658,"date":"2024-11-28T13:11:13","date_gmt":"2024-11-28T13:11:13","guid":{"rendered":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/unexpected-behaviour-of-fluent-simulation\/"},"modified":"2024-11-28T13:11:13","modified_gmt":"2024-11-28T13:11:13","slug":"unexpected-behaviour-of-fluent-simulation","status":"publish","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/unexpected-behaviour-of-fluent-simulation\/","title":{"rendered":"Unexpected behaviour of Fluent simulation"},"content":{"rendered":"<p>&lt;p&gt;Dear Ansys community&lt;\/p&gt;&lt;p&gt;I am performing a simple simulation of a single phase fluid flow in a rod bundle geometry. I use only walls (no slip, no roughness) as well as periodic conditions on top, bottom, front, back and left and right side. I set all fluid properties to constants, such that I achieve a Reynolds number of 5000. Now I simulate both, a crossflow and a streamwise flow, by setting the periodic mass flow rate to the propper direction. While for corssflow, I get reasonable results, I do not get so for the streamwise flow. In the streamwise case, I get an asymmetric velocity and (if turned on) temperature profile. This happens for different turbulence models and for different meshes,&lt;\/p&gt;&lt;p&gt;I tried very crude meshes without any wall inflations, furthermore I tried very fine meshes, the results are always pretty much the same.&nbsp;&lt;\/p&gt;&lt;p&gt;I tried to run transient solver instead of steady, the results are literally the same.Regarding the convergence, there are no problems, the case converges arbitrarily low, depending on the number of iterations. Also, the extracted data do not change reasonably, no matter how small the residual gets, i.e. there are no oscillating results.&lt;\/p&gt;&lt;p&gt;The following picture shows the streamwise velocity, I changed the colorscale a bit, such that the difference between the left and right half of the symetric geometry can be seen.&nbsp;&lt;\/p&gt;&lt;p&gt;<img decoding=\"async\" src=\"https:\/\/innovationspace.ansys.com\/forum\/wp-content\/uploads\/sites\/2\/2024\/11\/28-11-2024-1732798564-corruptvel.png\" alt=\"\" \/>&lt;\/p&gt;&lt;p&gt;It would be great if someone could help me out with this issue.&lt;\/p&gt;&lt;p&gt;Best regards&lt;\/p&gt;&lt;p&gt;&nbsp;&lt;\/p&gt;&lt;p&gt;Benjamin&lt;\/p&gt;<\/p>\n","protected":false},"template":"","class_list":["post-395658","topic","type-topic","status-publish","hentry"],"aioseo_notices":[],"aioseo_head":"\n\t\t<!-- All in One SEO 4.9.10 - aioseo.com -->\n\t<meta name=\"description\" content=\"Dear Ansys communityI am performing a simple simulation of a single phase fluid flow in a rod bundle geometry. I use only walls (no slip, no roughness) as well as periodic conditions on top, bottom, front, back and left and right side. I set all fluid properties to constants, such that I achieve a Reynolds\" \/>\n\t<meta name=\"robots\" content=\"max-image-preview:large\" \/>\n\t<link rel=\"canonical\" href=\"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/unexpected-behaviour-of-fluent-simulation\/\" \/>\n\t<meta name=\"generator\" content=\"All in One SEO (AIOSEO) 4.9.10\" \/>\n\t\t<meta property=\"og:locale\" content=\"en_US\" \/>\n\t\t<meta property=\"og:site_name\" content=\"Ansys Learning Forum | Ansys Innovation Space\" \/>\n\t\t<meta property=\"og:type\" content=\"article\" \/>\n\t\t<meta property=\"og:title\" content=\"Unexpected behaviour of Fluent simulation | Ansys Learning Forum\" \/>\n\t\t<meta property=\"og:description\" content=\"Dear Ansys communityI am performing a simple simulation of a single phase fluid flow in a rod bundle geometry. I use only walls (no slip, no roughness) as well as periodic conditions on top, bottom, front, back and left and right side. I set all fluid properties to constants, such that I achieve a Reynolds\" \/>\n\t\t<meta property=\"og:url\" content=\"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/unexpected-behaviour-of-fluent-simulation\/\" \/>\n\t\t<meta property=\"article:published_time\" content=\"2024-11-28T13:11:13+00:00\" \/>\n\t\t<meta property=\"article:modified_time\" content=\"2024-11-28T13:11:13+00:00\" \/>\n\t\t<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n\t\t<meta name=\"twitter:title\" content=\"Unexpected behaviour of Fluent simulation | Ansys Learning Forum\" \/>\n\t\t<meta name=\"twitter:description\" content=\"Dear Ansys communityI am performing a simple simulation of a single phase fluid flow in a rod bundle geometry. I use only walls (no slip, no roughness) as well as periodic conditions on top, bottom, front, back and left and right side. I set all fluid properties to constants, such that I achieve a Reynolds\" \/>\n\t\t<script type=\"application\/ld+json\" class=\"aioseo-schema\">\n\t\t\t{\"@context\":\"https:\\\/\\\/schema.org\",\"@graph\":[{\"@type\":\"BreadcrumbList\",\"@id\":\"https:\\\/\\\/innovationspace.ansys.com\\\/forum\\\/forums\\\/topic\\\/unexpected-behaviour-of-fluent-simulation\\\/#breadcrumblist\",\"itemListElement\":[{\"@type\":\"ListItem\",\"@id\":\"https:\\\/\\\/innovationspace.ansys.com\\\/forum#listItem\",\"position\":1,\"name\":\"Home\",\"item\":\"https:\\\/\\\/innovationspace.ansys.com\\\/forum\",\"nextItem\":{\"@type\":\"ListItem\",\"@id\":\"https:\\\/\\\/innovationspace.ansys.com\\\/forum\\\/topics\\\/#listItem\",\"name\":\"Topics\"}},{\"@type\":\"ListItem\",\"@id\":\"https:\\\/\\\/innovationspace.ansys.com\\\/forum\\\/topics\\\/#listItem\",\"position\":2,\"name\":\"Topics\",\"item\":\"https:\\\/\\\/innovationspace.ansys.com\\\/forum\\\/topics\\\/\",\"nextItem\":{\"@type\":\"ListItem\",\"@id\":\"https:\\\/\\\/innovationspace.ansys.com\\\/forum\\\/forums\\\/topic\\\/unexpected-behaviour-of-fluent-simulation\\\/#listItem\",\"name\":\"Unexpected behaviour of Fluent simulation\"},\"previousItem\":{\"@type\":\"ListItem\",\"@id\":\"https:\\\/\\\/innovationspace.ansys.com\\\/forum#listItem\",\"name\":\"Home\"}},{\"@type\":\"ListItem\",\"@id\":\"https:\\\/\\\/innovationspace.ansys.com\\\/forum\\\/forums\\\/topic\\\/unexpected-behaviour-of-fluent-simulation\\\/#listItem\",\"position\":3,\"name\":\"Unexpected behaviour of Fluent simulation\",\"previousItem\":{\"@type\":\"ListItem\",\"@id\":\"https:\\\/\\\/innovationspace.ansys.com\\\/forum\\\/topics\\\/#listItem\",\"name\":\"Topics\"}}]},{\"@type\":\"Organization\",\"@id\":\"https:\\\/\\\/innovationspace.ansys.com\\\/forum\\\/#organization\",\"name\":\"Ansys Learning Forum\",\"description\":\"Ansys Innovation Space\",\"url\":\"https:\\\/\\\/innovationspace.ansys.com\\\/forum\\\/\"},{\"@type\":\"WebPage\",\"@id\":\"https:\\\/\\\/innovationspace.ansys.com\\\/forum\\\/forums\\\/topic\\\/unexpected-behaviour-of-fluent-simulation\\\/#webpage\",\"url\":\"https:\\\/\\\/innovationspace.ansys.com\\\/forum\\\/forums\\\/topic\\\/unexpected-behaviour-of-fluent-simulation\\\/\",\"name\":\"Unexpected behaviour of Fluent simulation | Ansys Learning Forum\",\"description\":\"Dear Ansys communityI am performing a simple simulation of a single phase fluid flow in a rod bundle geometry. I use only walls (no slip, no roughness) as well as periodic conditions on top, bottom, front, back and left and right side. I set all fluid properties to constants, such that I achieve a Reynolds\",\"inLanguage\":\"en-US\",\"isPartOf\":{\"@id\":\"https:\\\/\\\/innovationspace.ansys.com\\\/forum\\\/#website\"},\"breadcrumb\":{\"@id\":\"https:\\\/\\\/innovationspace.ansys.com\\\/forum\\\/forums\\\/topic\\\/unexpected-behaviour-of-fluent-simulation\\\/#breadcrumblist\"},\"datePublished\":\"2024-11-28T13:11:13+00:00\",\"dateModified\":\"2024-11-28T13:11:13+00:00\"},{\"@type\":\"WebSite\",\"@id\":\"https:\\\/\\\/innovationspace.ansys.com\\\/forum\\\/#website\",\"url\":\"https:\\\/\\\/innovationspace.ansys.com\\\/forum\\\/\",\"name\":\"Ansys Learning Forum\",\"description\":\"Ansys Innovation Space\",\"inLanguage\":\"en-US\",\"publisher\":{\"@id\":\"https:\\\/\\\/innovationspace.ansys.com\\\/forum\\\/#organization\"}}]}\n\t\t<\/script>\n\t\t<!-- All in One SEO -->\n\n","aioseo_head_json":{"title":"Unexpected behaviour of Fluent simulation | Ansys Learning Forum","description":"Dear Ansys communityI am performing a simple simulation of a single phase fluid flow in a rod bundle geometry. I use only walls (no slip, no roughness) as well as periodic conditions on top, bottom, front, back and left and right side. I set all fluid properties to constants, such that I achieve a Reynolds","canonical_url":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/unexpected-behaviour-of-fluent-simulation\/","robots":"max-image-preview:large","keywords":"","webmasterTools":{"miscellaneous":""},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"BreadcrumbList","@id":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/unexpected-behaviour-of-fluent-simulation\/#breadcrumblist","itemListElement":[{"@type":"ListItem","@id":"https:\/\/innovationspace.ansys.com\/forum#listItem","position":1,"name":"Home","item":"https:\/\/innovationspace.ansys.com\/forum","nextItem":{"@type":"ListItem","@id":"https:\/\/innovationspace.ansys.com\/forum\/topics\/#listItem","name":"Topics"}},{"@type":"ListItem","@id":"https:\/\/innovationspace.ansys.com\/forum\/topics\/#listItem","position":2,"name":"Topics","item":"https:\/\/innovationspace.ansys.com\/forum\/topics\/","nextItem":{"@type":"ListItem","@id":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/unexpected-behaviour-of-fluent-simulation\/#listItem","name":"Unexpected behaviour of Fluent simulation"},"previousItem":{"@type":"ListItem","@id":"https:\/\/innovationspace.ansys.com\/forum#listItem","name":"Home"}},{"@type":"ListItem","@id":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/unexpected-behaviour-of-fluent-simulation\/#listItem","position":3,"name":"Unexpected behaviour of Fluent simulation","previousItem":{"@type":"ListItem","@id":"https:\/\/innovationspace.ansys.com\/forum\/topics\/#listItem","name":"Topics"}}]},{"@type":"Organization","@id":"https:\/\/innovationspace.ansys.com\/forum\/#organization","name":"Ansys Learning Forum","description":"Ansys Innovation Space","url":"https:\/\/innovationspace.ansys.com\/forum\/"},{"@type":"WebPage","@id":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/unexpected-behaviour-of-fluent-simulation\/#webpage","url":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/unexpected-behaviour-of-fluent-simulation\/","name":"Unexpected behaviour of Fluent simulation | Ansys Learning Forum","description":"Dear Ansys communityI am performing a simple simulation of a single phase fluid flow in a rod bundle geometry. I use only walls (no slip, no roughness) as well as periodic conditions on top, bottom, front, back and left and right side. I set all fluid properties to constants, such that I achieve a Reynolds","inLanguage":"en-US","isPartOf":{"@id":"https:\/\/innovationspace.ansys.com\/forum\/#website"},"breadcrumb":{"@id":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/unexpected-behaviour-of-fluent-simulation\/#breadcrumblist"},"datePublished":"2024-11-28T13:11:13+00:00","dateModified":"2024-11-28T13:11:13+00:00"},{"@type":"WebSite","@id":"https:\/\/innovationspace.ansys.com\/forum\/#website","url":"https:\/\/innovationspace.ansys.com\/forum\/","name":"Ansys Learning Forum","description":"Ansys Innovation Space","inLanguage":"en-US","publisher":{"@id":"https:\/\/innovationspace.ansys.com\/forum\/#organization"}}]},"og:locale":"en_US","og:site_name":"Ansys Learning Forum | Ansys Innovation Space","og:type":"article","og:title":"Unexpected behaviour of Fluent simulation | Ansys Learning Forum","og:description":"Dear Ansys communityI am performing a simple simulation of a single phase fluid flow in a rod bundle geometry. I use only walls (no slip, no roughness) as well as periodic conditions on top, bottom, front, back and left and right side. I set all fluid properties to constants, such that I achieve a Reynolds","og:url":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/unexpected-behaviour-of-fluent-simulation\/","article:published_time":"2024-11-28T13:11:13+00:00","article:modified_time":"2024-11-28T13:11:13+00:00","twitter:card":"summary_large_image","twitter:title":"Unexpected behaviour of Fluent simulation | Ansys Learning Forum","twitter:description":"Dear Ansys communityI am performing a simple simulation of a single phase fluid flow in a rod bundle geometry. I use only walls (no slip, no roughness) as well as periodic conditions on top, bottom, front, back and left and right side. I set all fluid properties to constants, such that I achieve a Reynolds"},"aioseo_meta_data":{"post_id":"395658","title":null,"description":null,"keywords":null,"keyphrases":null,"primary_term":null,"canonical_url":null,"og_title":null,"og_description":null,"og_object_type":"default","og_image_type":"default","og_image_url":null,"og_image_width":null,"og_image_height":null,"og_image_custom_url":null,"og_image_custom_fields":null,"og_video":null,"og_custom_url":null,"og_article_section":null,"og_article_tags":null,"twitter_use_og":false,"twitter_card":"default","twitter_image_type":"default","twitter_image_url":null,"twitter_image_custom_url":null,"twitter_image_custom_fields":null,"twitter_title":null,"twitter_description":null,"schema":{"blockGraphs":[],"customGraphs":[],"default":{"data":{"Article":[],"Course":[],"Dataset":[],"FAQPage":[],"Movie":[],"Person":[],"Product":[],"ProductReview":[],"Car":[],"Recipe":[],"Service":[],"SoftwareApplication":[],"WebPage":[]},"graphName":"","isEnabled":true},"graphs":[]},"schema_type":"default","schema_type_options":null,"pillar_content":false,"robots_default":true,"robots_noindex":false,"robots_noarchive":false,"robots_nosnippet":false,"robots_nofollow":false,"robots_noimageindex":false,"robots_noodp":false,"robots_notranslate":false,"robots_max_snippet":null,"robots_max_videopreview":null,"robots_max_imagepreview":"large","priority":null,"frequency":null,"local_seo":null,"limit_modified_date":false,"created":"2025-10-19 09:44:14","updated":"2026-09-17 12:29:17","ai":null,"breadcrumb_settings":null,"seo_analyzer_scan_date":null},"aioseo_breadcrumb":"<div class=\"aioseo-breadcrumbs\"><span class=\"aioseo-breadcrumb\">\n\t\t\t<a href=\"https:\/\/innovationspace.ansys.com\/forum\" title=\"Home\">Home<\/a>\n\t\t<\/span><span class=\"aioseo-breadcrumb-separator\">&raquo;<\/span><span class=\"aioseo-breadcrumb\">\n\t\t\t<a href=\"https:\/\/innovationspace.ansys.com\/forum\/topics\/\" title=\"Topics\">Topics<\/a>\n\t\t<\/span><span class=\"aioseo-breadcrumb-separator\">&raquo;<\/span><span class=\"aioseo-breadcrumb\">\n\t\t\tUnexpected behaviour of Fluent simulation\n\t\t<\/span><\/div>","aioseo_breadcrumb_json":[{"label":"Home","link":"https:\/\/innovationspace.ansys.com\/forum"},{"label":"Topics","link":"https:\/\/innovationspace.ansys.com\/forum\/topics\/"},{"label":"Unexpected behaviour of Fluent simulation","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/unexpected-behaviour-of-fluent-simulation\/"}],"acf":[],"custom_fields":[{"0":{"_bbp_forum_id":["27792"],"_bbp_topic_id":["395658"],"_bbp_author_ip":["129.129.213.118"],"_bbp_reply_count":["2"],"_bbp_reply_count_hidden":["0"],"_bbp_voice_count":["3"],"_bbp_engagement":["486913","13659","51510"],"_btv_view_count":["175"],"_bbp_topic_status":["unanswered"],"_bbp_subscription":["13659","51510"],"_bbp_last_reply_id":["395704"],"_bbp_last_active_id":["395704"],"_bbp_last_active_time":["2024-11-29 01:52:22"]},"test":"benjamin-arnoldpsi-ch"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/395658","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\/395658\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=395658"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}