{"id":31699,"date":"2018-11-22T10:33:41","date_gmt":"2018-11-22T10:33:41","guid":{"rendered":"\/forum\/forums\/topic\/determining-the-cause-of-negative-pressure\/"},"modified":"2018-11-22T10:33:41","modified_gmt":"2018-11-22T10:33:41","slug":"determining-the-cause-of-negative-pressure","status":"closed","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/determining-the-cause-of-negative-pressure\/","title":{"rendered":"Determining the cause of negative pressure."},"content":{"rendered":"<p>Hello!<\/p>\n<p><\/p>\n<p>I am trying to simulate 3D flow over solar panels and determine what kind of loads do they face in a high speed wind storm type of situation.<img decoding=\"async\" src=\"https:\/\/us.v-cdn.net\/6032193\/uploads\/attachments\/f497e181-cb97-413a-af6c-a97500be4726\/5576f7f1-4d0b-4161-b254-a9a000a9f9f5_streamlines.jpg?width=690&amp;upscale=false\" alt=\"\"><\/p>\n<p><\/p>\n<p>the wind is coming from behind them and the streamlines take the shape above. Then i constructed 3 lines near the top of the panels and attempted to find out the variable pressure from right to left.<\/p>\n<p><\/p>\n<p><img decoding=\"async\" src=\"https:\/\/us.v-cdn.net\/6032193\/uploads\/attachments\/f497e181-cb97-413a-af6c-a97500be4726\/5afaf60b-cee7-4a92-b6f1-a9a000abcd2c_pressurelines.jpg?width=690&amp;upscale=false\" alt=\"\"><\/p>\n<p><\/p>\n<p>&nbsp;<\/p>\n<p><\/p>\n<p>&nbsp;<\/p>\n<p><\/p>\n<p>When i plotted these lines in a chart, the pressure just below the panels where the density of streamlines is less came out to be a negative value.<img decoding=\"async\" src=\"https:\/\/us.v-cdn.net\/6032193\/uploads\/attachments\/f497e181-cb97-413a-af6c-a97500be4726\/a9cb8055-05bd-448b-9b55-a9a000ab7d56_chart1.jpg?width=690&amp;upscale=false\" alt=\"\"><\/p>\n<p><\/p>\n<p>I thought they may come out to be low but i don&#8217;t know why they come out to be negative. Is this maybe because the air above the panels is moving at a faster rate and therefore have lower pressure than the air between the panels and thus the air gets sucked upwards and leaves a negative pressure between the panels. Please share if there is any other rational explanation for the phenomenon. Thanks.<\/p>\n","protected":false},"template":"","class_list":["post-31699","topic","type-topic","status-closed","hentry"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_old_topic_id":["3871"],"_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":["2256"],"_bbp_topic_status":["unanswered"],"_bbp_status":["publish"],"_bbp_topic_id":["31699"],"_bbp_forum_id":["27792"],"_bbp_engagement":["62","199","22555","159397"],"_bbp_voice_count":["4"],"_bbp_reply_count":["4"],"_bbp_last_reply_id":["70246"],"_bbp_last_active_id":["70246"],"_bbp_last_active_time":["2018-11-23 04:49:03"]},"test":"sam_5195"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/31699","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\/31699\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=31699"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}