{"id":31723,"date":"2018-11-23T14:11:55","date_gmt":"2018-11-23T14:11:55","guid":{"rendered":"\/forum\/forums\/topic\/turbulent-channel-flow-some-questions\/"},"modified":"2018-11-23T14:11:55","modified_gmt":"2018-11-23T14:11:55","slug":"turbulent-channel-flow-some-questions","status":"closed","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/turbulent-channel-flow-some-questions\/","title":{"rendered":"Turbulent Channel Flow: Some questions"},"content":{"rendered":"

Hello guys! I try to make a simulation of classical Turbulent Channel Flow. <\/p>\n

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I’m basing my simulation on the work of Moser and Kim (1999) and I want to simulate for Rethau values equal to 180, 300, and 590. I found, as it seems, a PowerPoint presentation from Stanford University with comments and data on how to model this type in the images below. In the image have the boundary conditions used, material parameters, initial conditions, solver setup, etc.. <\/p>\n

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So I use same initial conditions, same geometry dimensions, a similar grid and k-epsilon with enhanced wall treatment. And I get the results in the image below. <\/p>\n

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As We can see in the first image (that I get in the internet) the TKE Contour looks like a channel flow in a downstream region, but my TKE Contour looks like a upstream region (as if the flow were coming out of a tank and flowing into the channel). By this (and other divergences, like the values of TKE), I have some questions:<\/p>\n

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– How Can I input the initial conditions: inlet and outlet conditions as a Periodic Boundary Conditions?<\/p>\n

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– What do I need to change to make my simulation look like the first image?<\/p>\n

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– The variable y + by default already has in FLUENT, how can I insert the variable u +? (I ask this because I found several formulas on the internet).<\/p>\n

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– How can I compute the value of uthau and Rethau to ensure if I have the values I want?<\/p>\n

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I decided to test this in a simple 2D simulation to understand this issue of periodic boundaries and how to model a zero pressure gradient in order to heal my doubts and be able to perform this 3D simulation using LES.<\/p>\n

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I am immensely grateful for those who read and help me, I hope this helps other users in the community.<\/p>\n

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Thanks,<\/p>\n

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Mantovani. <\/p>\n

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 <\/p>\n","protected":false},"template":"","class_list":["post-31723","topic","type-topic","status-closed","hentry"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_old_topic_id":["3895"],"_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":["1187"],"_bbp_topic_status":["unanswered"],"_bbp_status":["publish"],"_bbp_topic_id":["31723"],"_bbp_forum_id":["27792"],"_bbp_engagement":["59","199","22555","155059","168327"],"_bbp_voice_count":["5"],"_bbp_reply_count":["13"],"_bbp_last_reply_id":["114522"],"_bbp_last_active_id":["114522"],"_bbp_last_active_time":["2020-05-14 13:34:32"]},"test":"jose-mantovani"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/31723","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\/31723\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=31723"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}