{"id":36385,"date":"2019-07-07T01:36:57","date_gmt":"2019-07-07T01:36:57","guid":{"rendered":"\/forum\/forums\/topic\/velocity-contour-is-very-unreasonable-while-other-variable-contour-is-reasonable\/"},"modified":"2019-07-07T01:36:57","modified_gmt":"2019-07-07T01:36:57","slug":"velocity-contour-is-very-unreasonable-while-other-variable-contour-is-reasonable","status":"closed","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/velocity-contour-is-very-unreasonable-while-other-variable-contour-is-reasonable\/","title":{"rendered":"velocity contour is very unreasonable while other variable contour is reasonable?"},"content":{"rendered":"

Hi all,<\/p>\n

<\/p>\n

I posted some threads before for a soot cake combustion project. Now I get some results. The maximum temperature during combustion is very close to literature and soot is consumed in similar duration with literature. At first, I believed that I just got perfect results. Then I found the shape of high temperature region was different with literature though the magnitude was very close. I put literature and my result for temperature contour below:<\/p>\n

<\/p>\n

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<\/p>\n

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<\/p>\n

The maximum temperature is very similar which are 853k and 858k respectively. It’s just the shape of the high temperature region is different. Then I found that the inconsistency of temperature distribution is because I have very unreasonable velocity field.<\/p>\n

<\/p>\n

I checked my Y-velocity contour and found my model could not capture the effect of end wall. There should be a very large negative Y-velocity at end of the channel wall and gas was forced to flow through porous media to the outlet channel.<\/p>\n

<\/p>\n

I reloaded my UDFs and UDS and then calculated a pure flow instead. Perfect velocity contour was obtained as follows:<\/p>\n

<\/p>\n

\"\"<\/p>\n

<\/p>\n

As long as UDFs and UDS are involved, velocity contour becomes very unreasonable. More strange thing is though my model can not capture effect of end wall, it can capture the effect of a porous step in front part of the inlet channel. I put the Y-velocity contour near this step below:<\/p>\n

<\/p>\n

\"\"<\/p>\n

<\/p>\n

At first, I suspected it was due to continuity equation was not converged. Then I checked the pure mass flow between inlet and outlet. The net mass flow showed that continuity was satisfied.<\/p>\n

<\/p>\n

Can anybody give me some suggestions?<\/p>\n

<\/p>\n

Best <\/p>\n

<\/p>\n

Weiqiang<\/p>\n","protected":false},"template":"","class_list":["post-36385","topic","type-topic","status-closed","hentry"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_old_topic_id":["8557"],"_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":["1313"],"_bbp_subscription":["236081"],"_bbp_topic_status":["unanswered"],"_bbp_status":["publish"],"_bbp_topic_id":["36385"],"_bbp_forum_id":["27792"],"_bbp_engagement":["199","22555","156533"],"_bbp_voice_count":["3"],"_bbp_reply_count":["8"],"_bbp_last_reply_id":["89323"],"_bbp_last_active_id":["89323"],"_bbp_last_active_time":["2019-07-11 20:11:18"]},"test":"weiqiang-liu"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/36385","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\/36385\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=36385"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}