{"id":36205,"date":"2019-06-27T11:46:36","date_gmt":"2019-06-27T11:46:36","guid":{"rendered":"\/forum\/forums\/topic\/pressure-based-solver-vs-density-based-solver\/"},"modified":"2019-06-27T11:46:36","modified_gmt":"2019-06-27T11:46:36","slug":"pressure-based-solver-vs-density-based-solver","status":"closed","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/pressure-based-solver-vs-density-based-solver\/","title":{"rendered":"Pressure Based Solver vs Density Based Solver"},"content":{"rendered":"<p>Hi,<\/p>\n<p><\/p>\n<p>I&#8217;m trying to simulate a shock-wave&nbsp;travelling&nbsp;in a tunnel and&nbsp;expansion to the atmosphere (see attached figure showing the domain and location of the shock-wave). I&#8217;m assessing the results obtained using a&nbsp;Pressure Based Solver (PBS) and Density Based Solver (DBS) when the shock-wave is still in the tunnel. As you can see in the attached graph (taken at the profile marked in black in the domain) both solvers provide almost similar results. At the plateau of the shock-wave, the PBS produces&nbsp;larger pressure oscillations&nbsp;than the DBS. My questions are:<\/p>\n<p><\/p>\n<ul><\/p>\n<li>Why are happening these oscillations?&nbsp;<\/li>\n<p><\/p>\n<li>Why the solvers produce different results?<\/li>\n<p><\/p>\n<li>Based on this result, what solver should I use and why?<\/li>\n<p>\n<\/ul>\n<p><\/p>\n<p>Thank you.<\/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\/9e02eced-71d4-4e22-902a-aa7900c01bdb_ex-2-domain.jpg?width=690&amp;upscale=false\" alt=\"Domain\"><\/p>\n<p><\/p>\n<p>Tunnel wall &#8220;wall&#8221; (white line); domain outlet &#8220;pressure outlet&#8221; (red lines); axisymmetric &#8220;axis&#8221; (yellow line); shock-wave position (green line); and longitudinal profile where results are taken (black line).<\/p>\n<p><\/p>\n<p><img decoding=\"async\" src=\"https:\/\/us.v-cdn.net\/6032193\/uploads\/attachments\/ae0d9f9e-acaa-4aab-be7f-aa1f00c0ac5e\/0a958931-e42a-401e-b026-aa7900c04080_ex-2-r275m-case-0.jpg?width=690&amp;upscale=false\" alt=\"\"><\/p>\n","protected":false},"template":"","class_list":["post-36205","topic","type-topic","status-closed","hentry"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_old_topic_id":["8377"],"_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"],"_btv_view_count":["9813"],"_bbp_subscription":["239578"],"_bbp_topic_status":["unanswered"],"_bbp_status":["publish"],"_bbp_topic_id":["36205"],"_bbp_forum_id":["27792"],"_bbp_engagement":["22555","163954"],"_bbp_voice_count":["2"],"_bbp_reply_count":["13"],"_bbp_last_reply_id":["89633"],"_bbp_last_active_id":["89633"],"_bbp_last_active_time":["2019-07-15 16:26:06"]},"test":"egorbena"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/36205","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\/36205\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=36205"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}