{"id":391437,"date":"2024-10-25T23:32:51","date_gmt":"2024-10-25T23:32:51","guid":{"rendered":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/finite-rate-direct-source-combustion-prediction-issue\/"},"modified":"2024-11-06T19:26:00","modified_gmt":"2024-11-06T19:26:00","slug":"finite-rate-direct-source-combustion-prediction-issue","status":"answered","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/finite-rate-direct-source-combustion-prediction-issue\/","title":{"rendered":"Finite Rate &#8211; Direct Source Combustion Prediction Issue"},"content":{"rendered":"<p>&lt;p&gt;&lt;p&gt;Hi, I was trying methane-air combustion with hot air at 1000K and methane at atmospheric temperature, with an air mass flow rate of 2 kg\/s and methane at 0.1 kg\/s, using the default methane-air 5 species.&lt;\/p&gt;&lt;p&gt;When using the finite-rate model, the direct source solver cannot predict combustion, whereas the relax-to-chemical-equilibrium solver can. I have also tried the eddy dissipation model, where both the direct source and equilibrium solvers can predict combustion. However, since the finite-rate direct source model is more accurate, I want to solve it solely with the finite-rate direct source. Is that actually possible? Also, why are these two chemical solvers behaving differently?&lt;\/p&gt;&lt;p&gt;The attached picture shows the difference in results between the finite-rate direct source and the relax-to-chemical-equilibrium approaches. Why they are behaving so differently and please help in understanding what is happening in the background. I have read the theory guide and user guides properly. Thank you.&lt;br&gt;&lt;br&gt;<img decoding=\"async\" src=\"https:\/\/innovationspace.ansys.com\/forum\/wp-content\/uploads\/sites\/2\/2024\/10\/25-10-2024-1729899164-mceclip0.png\" \/>&lt;\/p&gt;&lt;\/p&gt;<\/p>\n","protected":false},"template":"","class_list":["post-391437","topic","type-topic","status-answered","hentry"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_subscription":["134342","101181"],"_bbp_author_ip":["70.49.90.111"],"_btv_view_count":["229"],"_bbp_topic_status":["answered"],"_bbp_likes_count":["1"],"_edit_last":["134342"],"_bbp_revision_log":["a:1:{i:392815;a:2:{s:6:\"author\";i:134342;s:6:\"reason\";s:0:\"\";}}"],"_bbp_topic_id":["391437"],"_bbp_forum_id":["27792"],"_bbp_engagement":["101181","134342"],"_bbp_voice_count":["2"],"_bbp_last_reply_id":["392892"],"_bbp_last_active_id":["392892"],"_bbp_last_active_time":["2024-11-06 05:09:58"]},"test":"uddin43uwindsor-ca"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/391437","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":1,"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/391437\/revisions"}],"predecessor-version":[{"id":392815,"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/391437\/revisions\/392815"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=391437"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}