{"id":89536,"date":"2019-07-14T21:45:53","date_gmt":"2019-07-14T21:45:53","guid":{"rendered":"\/forum\/forums\/reply\/89536\/"},"modified":"2019-07-14T21:45:53","modified_gmt":"2019-07-14T21:45:53","slug":"89536","status":"publish","type":"reply","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/reply\/89536\/","title":{"rendered":"Reply To: Pressure Based Solver vs Density Based Solver"},"content":{"rendered":"<p>Dear all,<\/p>\n<p><\/p>\n<p>I&nbsp;tried to solve the above transient problem using two different conditions for the outlet boundaries&nbsp;to assess the propagation of the shock-wave outside the tunnel. These are:<\/p>\n<p><\/p>\n<ul><\/p>\n<li>Pressure outlet using standard density based solver.<\/li>\n<p><\/p>\n<li>Pressure outlet using density based solver with acoustic wave model &#8211; non reflecting (to avoid unreal reflection of the shock-wave from the outlet boundaries).<\/li>\n<p>\n<\/ul>\n<p><\/p>\n<p>In the first approach, the shock wave is reflected at the boundaries. In the second approach, I wasn&#8217;t able to run the simulation from t = 0, when doing so, looks like a high pressure is entering from the outlets (see attached figure). Instead, if I run the simulation for some time-states&nbsp;with the pressure outlet using&nbsp;standard density based and then I switch to the acoustic wave model &#8211; non reflecting condition, the result is fine.<\/p>\n<p><\/p>\n<p>What setting should&nbsp;I use to be able to run a DBS-AWMNR from t = 0?<\/p>\n<p><\/p>\n<p>Thank you.<\/p>\n<p><\/p>\n<p>&nbsp;<\/p>\n<p><\/p>\n<p>Kind regards,<\/p>\n<p><\/p>\n<p>Eduardo<\/p>\n<p><\/p>\n<p><img decoding=\"async\" src=\"https:\/\/us.v-cdn.net\/6032193\/uploads\/attachments\/ae0d9f9e-acaa-4aab-be7f-aa1f00c0ac5e\/d736b235-0730-40cb-a517-aa8a0165f8eb_ex-2-dbs-awmnr-case-2b.jpg?width=690&amp;upscale=false\" alt=\"\"><\/p>\n","protected":false},"template":"","class_list":["post-89536","reply","type-reply","status-publish","hentry"],"aioseo_notices":[],"acf":[],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/replies\/89536","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/replies"}],"about":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/types\/reply"}],"version-history":[{"count":0,"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/replies\/89536\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=89536"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}