{"id":380766,"date":"2024-08-28T00:47:50","date_gmt":"2024-08-28T00:47:50","guid":{"rendered":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/mixing-of-gases-no-combustion\/"},"modified":"2024-08-28T00:47:50","modified_gmt":"2024-08-28T00:47:50","slug":"mixing-of-gases-no-combustion","status":"publish","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/mixing-of-gases-no-combustion\/","title":{"rendered":"mixing of gases, no combustion"},"content":{"rendered":"<p>&lt;div&gt;I want to simulate the following problem:&lt;\/div&gt;&lt;div&gt;I want to study the mixture of two gases, but without combustion. the flows are supersonic and there are a total of three inlets, two of which with oxidizer and one with fuel and the gases are not premixed with the other one. I only know their pressure, which is 6 Pa for oxidizer and 12 Pa for fuel.&lt;\/div&gt;&lt;div&gt;I have the following procedure:&nbsp;&lt;\/div&gt;&lt;div&gt;Sover: Density-based, Absolute velocity formulation, steady,&nbsp; 2D planar, no gravity&lt;\/div&gt;&lt;div&gt;Energy: on&lt;\/div&gt;&lt;div&gt;Viscous model: Spalart-Allmaras&lt;\/div&gt;&lt;div&gt;Speices Model: Species Transport (Ractions (volumetic) -uncheked ; Options( diffusions)-uncheked;)&lt;\/div&gt;&lt;div&gt;&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;Mixture Properties:&nbsp; Mixture species: air and h2&lt;\/div&gt;&lt;div&gt;&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;denisty: ideal-gas&lt;\/div&gt;&lt;div&gt;&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;cp- mixing law&lt;\/div&gt;&lt;div&gt;&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;thermal conductivity- constant 0.0454&lt;\/div&gt;&lt;div&gt;&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;viscosity- constant 1.72e-05&lt;\/div&gt;&lt;div&gt;&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; mass diffusivity-constant dilute approx 2.88e-05&lt;\/div&gt;&lt;div&gt;&nbsp;&lt;\/div&gt;&lt;div&gt;Boundary conditions:&nbsp;&lt;\/div&gt;&lt;div&gt;inlet air: pressure inlet: gauge tot. press. 600000&lt;\/div&gt;&lt;div&gt;supersonic\/initial gauge press: 600000&lt;\/div&gt;&lt;div&gt;thermal: 300&lt;\/div&gt;&lt;div&gt;species: h2: 0&lt;\/div&gt;&lt;div&gt;&nbsp;&lt;\/div&gt;&lt;div&gt;inlet h2: pressure inlet: gauge tot. press. 1200000&lt;\/div&gt;&lt;div&gt;supersonic\/initial gauge press: 1200000&lt;\/div&gt;&lt;div&gt;thermal: 290&lt;\/div&gt;&lt;div&gt;species: h2: 1&lt;\/div&gt;&lt;div&gt;&nbsp;&lt;\/div&gt;&lt;div&gt;outlet: gauge pressure: 100000&lt;\/div&gt;&lt;div&gt;thermal: 300&lt;\/div&gt;&lt;div&gt;species: h2: 0&lt;\/div&gt;&lt;div&gt;&nbsp;&lt;\/div&gt;&lt;div&gt;operating pressure: 0&lt;\/div&gt;&lt;div&gt;&nbsp;&lt;\/div&gt;&lt;div&gt;Solution methods:&nbsp;&lt;\/div&gt;&lt;div&gt;Formulation: implicit&lt;\/div&gt;&lt;div&gt;Flux-type: roe-fds&lt;\/div&gt;&lt;div&gt;Spatial discretization: gradient: least squares cell based&lt;\/div&gt;&lt;div&gt;&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;flow: second order upwind&lt;\/div&gt;&lt;div&gt;&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;modified turbulent viscoisty: second order upwind&lt;\/div&gt;&lt;div&gt;&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;pseudo time method: off&lt;\/div&gt;&lt;div&gt;&nbsp;&lt;\/div&gt;&lt;div&gt;Initialization: hybrid (no patch)&lt;\/div&gt;&lt;div&gt;Iterations steps: 10000&lt;\/div&gt;&lt;div&gt;&nbsp;&lt;\/div&gt;&lt;div&gt;when I run the simulation, the residuals go high (higher than e+04) and the simulation stops.&nbsp;&lt;\/div&gt;&lt;div&gt;what have I done wrong? What do you thinnk of my procedure? Is it plausible?&lt;\/div&gt;<\/p>\n","protected":false},"template":"","class_list":["post-380766","topic","type-topic","status-publish","hentry"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_subscription":["448404","199"],"_bbp_author_ip":["109.234.233.35"],"_btv_view_count":["342"],"_bbp_topic_status":["unanswered"],"_bbp_topic_id":["380766"],"_bbp_forum_id":["27792"],"_bbp_engagement":["199","448404"],"_bbp_voice_count":["2"],"_bbp_reply_count":["3"],"_bbp_last_reply_id":["381019"],"_bbp_last_active_id":["381019"],"_bbp_last_active_time":["2024-08-29 08:58:55"]},"test":"b-eglaicloud-com"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/380766","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\/380766\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=380766"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}