{"id":344826,"date":"2024-01-16T03:04:12","date_gmt":"2024-01-16T03:04:12","guid":{"rendered":"\/forum\/?post_type=topic&#038;p=344826"},"modified":"2024-01-16T03:04:12","modified_gmt":"2024-01-16T03:04:12","slug":"liquid-oxygen-jeta-multiphase-rocket-engine-combustion","status":"closed","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/liquid-oxygen-jeta-multiphase-rocket-engine-combustion\/","title":{"rendered":"Liquid Oxygen-JetA Multiphase Rocket Engine Combustion"},"content":{"rendered":"<p>Hi,<\/p>\n<p>&nbsp;<\/p>\n<p>I am trying to model the combustion of a liquid rocket engine. This rocket engine has an impinging injector where liquid oxygen and liquid jet fuel collide at 90 degrees to each ofther mixing and combusting. Shown below is a simplified schematic of what the internal volume looks like.<\/p>\n<p><img decoding=\"async\" src=\"\/forum\/wp-content\/uploads\/sites\/2\/2024\/01\/16-01-2024-1705369216-mceclip0.png\"><\/p>\n<p>I am modeling liquid<strong> Kerosene (Jet-A entering the combustion chamber at 300K)<\/strong> and <strong>Liquid Oxygen (LOX entering the combustion chamber @ 85K)<\/strong> burning inside a combustion chamber of 21 bar. My general plan of attack here is to first compute a steady state solution and then transition to a transient SBES model.<\/p>\n<p>Quick Mesh facts:<\/p>\n<ul>\n<li>Split into 60 degree rotational periodic domain<\/li>\n<li>~9Million Poly-hexcore cells for 60 degrees<\/li>\n<li>largest cell size is 0.7mm<\/li>\n<li>Skewness max 0.82 (avg 0.0024)<\/li>\n<li>Non-Ortho min 0.17 (average 0.99)<\/li>\n<\/ul>\n<p>&nbsp;<\/p>\n<p>For my Steady State Case:<\/p>\n<ul>\n<li>Steady State, Pressure Based Solver<\/li>\n<li>Energy On<\/li>\n<li>K-W SST model with Curvature correction<\/li>\n<li>Im currently using the species transport approach with a multi-step kerosene reaction mechanism (31 species). This is the only option as the non-premixed combustion model cannot handle oxidizer injection (mixture fraction is not tied to O2 concentration).\n<ul>\n<li>Eddy Dissipation Model<\/li>\n<li>With relax to chemical equilibrium selected<\/li>\n<li>Diffusion energy source.<\/li>\n<\/ul>\n<\/li>\n<li>Discrete Phase is on\n<ul>\n<li>Continous Interaction On<\/li>\n<li>Update DPM Sources every flow iteration<\/li>\n<li>Dpm Iteration Interval Set to 1<\/li>\n<li>Unsteady particle tracking (required to model the colisions of the LOX\/JetA Jets)<\/li>\n<li>Physical Models -&gt; Stochastic collision<\/li>\n<li>Linearized Source terms + Coupled Heat-mass solution<\/li>\n<li>Injections are defined by surface injections with eddy random walk model<\/li>\n<\/ul>\n<\/li>\n<li>Mixture set to ideal gas for density<\/li>\n<li>Liquid Oxygen Droplet and JetA Liquid Droplets<\/li>\n<li>Coupled Solver\n<ul>\n<li>1st Order Solution for everything<\/li>\n<li>Warped Face gradient Correction<\/li>\n<li>High order Term relaxation<\/li>\n<\/ul>\n<\/li>\n<li>Controls\n<ul>\n<li>Flow courant number 5<\/li>\n<li>All URF&#8217;s are 0.5 except for discrete phase sources at 0.1<\/li>\n<\/ul>\n<\/li>\n<li>Hybrid initialization<\/li>\n<\/ul>\n<p>I am unable to get a stable solution with constant divergence. Im not sure if its the DPM solver settings or choosing DPM as opposed to Dense DPM or Eulerian. Any help or guidance here would be appreciated. I have tried following all of ANSYS&#8217; best practices under the combustion section of the Ansys Learning Hub. Have liquid rocket combustion problems ever been done before on FLUENT?<\/p>\n","protected":false},"template":"","class_list":["post-344826","topic","type-topic","status-closed","hentry","topic-tag-multiphase_models-1","topic-tag-cfd-combustion","topic-tag-dpm","topic-tag-gas-liquid-flow","topic-tag-species","topic-tag-supersonic-flow-1"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_author_ip":["23.47.58.53"],"_bbp_subscription":["36742","199","337136","61006"],"_btv_view_count":["2076"],"_bbp_topic_status":["unanswered"],"_bbp_topic_id":["344826"],"_bbp_forum_id":["27792"],"_bbp_engagement":["199","36742","61006","337136"],"_bbp_voice_count":["4"],"_bbp_reply_count":["15"],"_bbp_last_reply_id":["347959"],"_bbp_last_active_id":["347959"],"_bbp_last_active_time":["2024-01-31 15:10:44"],"_bbp_likes_count":["2"]},"test":"hudson-pastuszkospaceconcordia-ca"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/344826","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":2,"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/344826\/revisions"}],"predecessor-version":[{"id":344834,"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/344826\/revisions\/344834"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=344826"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}