{"id":166737,"date":"2022-02-25T08:26:44","date_gmt":"2022-02-25T08:26:44","guid":{"rendered":"\/forum\/forums\/topic\/why-not-getting-exact-mach-number-as-specified-at-inlet\/"},"modified":"2022-03-11T09:51:51","modified_gmt":"2022-03-11T09:51:51","slug":"why-not-getting-exact-mach-number-as-specified-at-inlet","status":"closed","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/why-not-getting-exact-mach-number-as-specified-at-inlet\/","title":{"rendered":"Why Not Getting Exact Mach Number As Specified At Inlet?"},"content":{"rendered":"<div class=\"Item-Body\">\n<div class=\"Message userContent\">\n<p>I want to specify exact Mach number = 1, at inlet of divergent section of nozzle.<\/p>\n<p>I have used isentropic relations to find the static pressure corresponding to M = 1 and given stagnation pressure and I am specifying the same values at Pressure inlet boundary condition.<\/p>\n<p><strong><em>And I am using air with specific heat ratio = 1.2, R = 349.7208 not the default value of 1.4 and Mw = 28<\/em><\/strong><\/p>\n<p>So to consider that difference, I am finding Specific Heat Cp using this relation [ y*R\/(y-1) ] , then the molecular weight using the relation [ Universal Gas Constant\/R ] and substituting in Air Material section.<\/p>\n<div class=\"embedExternal embedImage\">\n<div class=\"embedExternal-content\">\n<a class=\"embedImage-link\" href=\"\/forum\/wp-content\/uploads\/forum-uploads\/230\/BJ8DO3V8GJR8.png\" rel=\"nofollow noopener\" target=\"_blank\"><br \/>\n<img decoding=\"async\" class=\"embedImage-img\" src=\"\/forum\/wp-content\/uploads\/forum-uploads\/230\/BJ8DO3V8GJR8.png\" alt=\"image.png\" \/><br \/>\n<\/a><\/p>\n","protected":false},"template":"","class_list":["post-166737","topic","type-topic","status-closed","hentry"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_btv_view_count":["2879"],"_bbp_likes_count":["0"],"_bbp_topic_status":["unanswered"],"_bbp_status":["publish"],"_bbp_topic_id":["166737"],"_bbp_forum_id":["27792"],"_bbp_engagement":["25","59","199","22555","214879"],"_bbp_voice_count":["5"],"_bbp_reply_count":["18"],"_bbp_last_reply_id":["206661"],"_bbp_last_active_id":["206661"],"_bbp_last_active_time":["2022-03-11 09:51:51"]},"test":"karthik29112kgmail-com"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/166737","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\/166737\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=166737"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}