{"id":40303,"date":"2020-01-21T20:24:28","date_gmt":"2020-01-21T20:24:28","guid":{"rendered":"\/forum\/forums\/topic\/courant-number-and-time-step-for-compressible-flow\/"},"modified":"2020-01-21T20:24:28","modified_gmt":"2020-01-21T20:24:28","slug":"courant-number-and-time-step-for-compressible-flow","status":"closed","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/courant-number-and-time-step-for-compressible-flow\/","title":{"rendered":"Courant number and time step for compressible flow"},"content":{"rendered":"<p>Dear experts,<\/p>\n<p><\/p>\n<p>I simulate a compressible transient flow with input conditions P = 0.25 MPa.<\/p>\n<p><\/p>\n<p>This question relates to the&nbsp;courant number&nbsp;and the condition CFL (C &lt;1) which determines the stability of many numerical methods.<\/p>\n<p><\/p>\n<p>My question is: How to calculate the courant number and time step for compressible flow and inlet condition P = 0.25 MPa?<\/p>\n<p><\/p>\n<p>I know there is a formula for an inlet velocity as shown below.:<\/p>\n<p><\/p>\n<p><img decoding=\"async\" src=\"https:\/\/us.v-cdn.net\/6032193\/uploads\/attachments\/e831b279-0427-445e-87d9-a98a01340b49\/8ffc2633-8da8-4777-84a8-ab49014c2932_15.jpg?width=690&amp;upscale=false\" alt=\"\"><\/p>\n<p><\/p>\n<p>But for an inlet pressure, I don&#8217;t know if there is a formula or a technique for the courant number?<\/p>\n<p><\/p>\n<p>Best regards,<\/p>\n<p><\/p>\n<p>SER<\/p>\n","protected":false},"template":"","class_list":["post-40303","topic","type-topic","status-closed","hentry"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_old_topic_id":["12483"],"_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":["522"],"_bbp_subscription":["237699"],"_bbp_topic_status":["unanswered"],"_bbp_status":["publish"],"_bbp_topic_id":["40303"],"_bbp_forum_id":["27792"],"_bbp_engagement":["22555","159999"],"_bbp_voice_count":["2"],"_bbp_reply_count":["3"],"_bbp_last_reply_id":["103156"],"_bbp_last_active_id":["103156"],"_bbp_last_active_time":["2020-01-22 12:04:21"]},"test":"abd-fs"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/40303","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\/40303\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=40303"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}