{"id":43567,"date":"2020-05-04T01:55:02","date_gmt":"2020-05-04T01:55:02","guid":{"rendered":"\/forum\/forums\/topic\/drag-coefficient-goes-immediately-to-zero\/"},"modified":"2020-05-04T01:55:02","modified_gmt":"2020-05-04T01:55:02","slug":"drag-coefficient-goes-immediately-to-zero","status":"closed","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/drag-coefficient-goes-immediately-to-zero\/","title":{"rendered":"Drag Coefficient Goes Immediately to Zero"},"content":{"rendered":"<p>Hello,<\/p>\n<p><\/p>\n<p>I am working on a CFD analysis in Fluent for an annular parachute to calculate its coefficient of drag. I have set up the coefficient of drag report and plot so I can see live results as the simulation is run. I put the surface area and diameter of the parachute into the reference value section, but I am not getting the correct results. The coefficient of drag goes almost immediately to zero when it should be around 2.2. I have watched several tutorials and none of them helped. I think the error may be in the reference value or boundary condition sections, but I&#8217;m not sure. Any help would be greatly appreciated!&nbsp;<\/p>\n<p><\/p>\n<p>The parachute is traveling at a constant 5.5 m\/s. I have included screen shots of the reference values and boundary conditions I currently have as well as the coefficient of drag plot.<\/p>\n<p><\/p>\n<p>&nbsp;<img decoding=\"async\" src=\"https:\/\/us.v-cdn.net\/6032193\/uploads\/attachments\/49c4fd51-77af-4f65-aea8-abb10017128b\/d6a5d530-563d-49f2-9e56-abb1001f1ab4_reference-values.jpg?width=690&amp;upscale=false\" alt=\"\"><\/p>\n<p><\/p>\n<p><img decoding=\"async\" src=\"https:\/\/us.v-cdn.net\/6032193\/uploads\/attachments\/49c4fd51-77af-4f65-aea8-abb10017128b\/ee59d1a2-05b3-43ec-bf1a-abb1001f2f6c_inlet-boundary-conditions.jpg?width=690&amp;upscale=false\" alt=\"\"><\/p>\n<p><\/p>\n<p><img decoding=\"async\" src=\"https:\/\/us.v-cdn.net\/6032193\/uploads\/attachments\/49c4fd51-77af-4f65-aea8-abb10017128b\/102b7e46-4752-4df0-9993-abb1001f3df3_outlet-boundary-conditions.jpg?width=690&amp;upscale=false\" alt=\"\"><\/p>\n<p><\/p>\n<p><img decoding=\"async\" src=\"https:\/\/us.v-cdn.net\/6032193\/uploads\/attachments\/49c4fd51-77af-4f65-aea8-abb10017128b\/bfe94513-8209-4691-b22c-abb1001f473d_cd-plot.jpg?width=690&amp;upscale=false\" alt=\"\"><\/p>\n<p><\/p>\n<p>&nbsp;<\/p>\n","protected":false},"template":"","class_list":["post-43567","topic","type-topic","status-closed","hentry"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_old_topic_id":["15748"],"_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"],"_btv_view_count":["2132"],"_bbp_subscription":["51791"],"_bbp_topic_status":["unanswered"],"_bbp_status":["publish"],"_bbp_topic_id":["43567"],"_bbp_forum_id":["27792"],"_bbp_engagement":["25","118","22555","176700"],"_bbp_voice_count":["4"],"_bbp_reply_count":["9"],"_bbp_last_reply_id":["113619"],"_bbp_last_active_id":["113619"],"_bbp_last_active_time":["2020-05-05 20:48:05"]},"test":"farrmi"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/43567","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\/43567\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=43567"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}