{"id":160177,"date":"2022-09-26T10:00:48","date_gmt":"2022-09-26T10:00:48","guid":{"rendered":"\/knowledge\/forums\/topic\/discovery-aim-tutorial-compressible-flow-through-a-nozzle\/"},"modified":"2023-08-16T06:33:39","modified_gmt":"2023-08-16T06:33:39","slug":"discovery-aim-tutorial-compressible-flow-through-a-nozzle","status":"publish","type":"topic","link":"https:\/\/innovationspace.ansys.com\/knowledge\/forums\/topic\/discovery-aim-tutorial-compressible-flow-through-a-nozzle\/","title":{"rendered":"Discovery AIM tutorial &#8211; Compressible Flow Through A Nozzle"},"content":{"rendered":"<p><strong>This example is taken from\u00a0<u><a href=\"https:\/\/confluence.cornell.edu\/display\/SIMULATION\/ANSYS+AIM+-+Compressible+Flow+in+a+Nozzle\" target=\"_blank\" rel=\"nofollow noopener noreferrer\">Cornell University&#8217;s\u00a0ANSYS AIM Learning Modules<\/a><\/u><\/strong><\/p>\n<hr \/>\n<nav class=\"toc -selected\">Contents<\/p>\n<ol class=\"toc__section -lev0\">\n<li class=\"toc__item -lev0\">Learning Goals<\/li>\n<li class=\"toc__item -lev0\">Problem Specification<\/li>\n<li class=\"toc__item -lev0\">Geometry<\/li>\n<li class=\"toc__item -lev0\">Mesh<\/li>\n<li class=\"toc__item -lev0\">Physics Setup<\/li>\n<li class=\"toc__item -lev0\">Results<\/li>\n<li class=\"toc__item -lev0\">Validation<\/li>\n<\/ol>\n<\/nav>\n<h4 content_id=\"learning-goals\" class=\"toc__permalink\" content_id=\"learning-goals\" class=\"toc__permalink\"  id=\"LEARNING-GOALS\">Learning Goals<\/h4>\n<p>In this tutorial,\u00a0you will\u00a0learn to:<\/p>\n<ul>\n<li>To determine the total pressure on the walls of the nozzle.<\/li>\n<li>To show the Mach number distribution along the cross-section of\u00a0flow field using Ansys AIM.<\/li>\n<\/ul>\n<hr \/>\n<h4 content_id=\"problem-specification\" class=\"toc__permalink\" content_id=\"problem-specification\" class=\"toc__permalink\"  id=\"PROBLEM-SPECIFICATION\"><strong>Problem Specification<\/strong><\/h4>\n<p>Compute the converging-diverging nozzle flow using AIM and plot the pressure and velocity (Mach number) graphs. The pressure at the inlet is 3 bar at 300 K.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-157416\" src=\"\/knowledge\/wp-content\/uploads\/sites\/4\/2022\/08\/HM-46.png\" alt=\" width=\"600\" height=\"295\" \/><\/p>\n<hr \/>\n<h4 content_id=\"geometry\" class=\"toc__permalink\" content_id=\"geometry\" class=\"toc__permalink\"  id=\"GEOMETRY\"><strong>Geometry<\/strong><\/h4>\n<p>The geometry of the Nozzle can be downloaded from\u00a0<a href=\"https:\/\/confluence.cornell.edu\/download\/attachments\/348591755\/CD_Nozzle.scdoc?version=1&amp;modificationDate=1502124417000&amp;api=v2\" target=\"_blank\" rel=\"nofollow noopener noreferrer\">here<\/a>\u00a0.<\/p>\n<p>The following video shows how to navigate through Discovery AIM to import the geometry.<\/p>\n<p><iframe loading=\"lazy\" class=\"vidyard_iframe\" src=\"\/\/play.vidyard.com\/7ZSpd8yEfvKm8DywYM3XfY.html?\" width=\"700\" height=\"400\" frameborder=\"0\" scrolling=\"no\" allowfullscreen=\"allowfullscreen\"><\/iframe><\/p>\n<hr \/>\n<h4 content_id=\"mesh\" class=\"toc__permalink\" content_id=\"mesh\" class=\"toc__permalink\"  id=\"MESH\"><strong>Mesh<\/strong><\/h4>\n<p>In this\u00a0example, we will be using\u00a0<strong>Automatic\u00a0Physics-Aware Meshing<\/strong>.\u00a0Automatic physics-aware meshing helps automate and simplify your problem setup. With automatic physics-aware meshing, the computational mesh is generated automatically based on the solution fidelity setting and the\u00a0physics inputs.<\/p>\n<hr \/>\n<h4 content_id=\"physics-setup\" class=\"toc__permalink\" content_id=\"physics-setup\" class=\"toc__permalink\"  id=\"PHYSICS-SETUP\"><strong>Physics Setup<\/strong><\/h4>\n<p>This video shows how to set up the Boundary Conditions for solving Compressible flow through the nozzle.<\/p>\n<p><iframe loading=\"lazy\" class=\"vidyard_iframe\" src=\"\/\/play.vidyard.com\/t4TKiVjMUVLNAfQJgMwuwa.html?\" width=\"700\" height=\"400\" frameborder=\"0\" scrolling=\"no\" allowfullscreen=\"allowfullscreen\"><\/iframe><\/p>\n<hr \/>\n<h4 content_id=\"results\" class=\"toc__permalink\" content_id=\"results\" class=\"toc__permalink\"  id=\"RESULTS\"><strong>Results<\/strong><\/h4>\n<p>This video explains how to determine the distribution of velocity vector through the nozzle volume and determine the pressure on the walls of the nozzle. It also explains how to determine the Mach number and produce a contour of it along the cross-sectional plane.<\/p>\n<p><iframe loading=\"lazy\" class=\"vidyard_iframe\" src=\"\/\/play.vidyard.com\/8CKPBR6D9pGG4z1WV88wjB.html?\" width=\"700\" height=\"400\" frameborder=\"0\" scrolling=\"no\" allowfullscreen=\"allowfullscreen\"><\/iframe><\/p>\n<hr \/>\n<h4 content_id=\"validation\" class=\"toc__permalink\" content_id=\"validation\" class=\"toc__permalink\"  id=\"\"><\/h4>\n<p><strong>Hand\u00a0Calculations<\/strong><\/p>\n<p>In quasi-one-dimensional flow for this converging-diverging nozzle, we expect that the Mach number at the inlet will be subsonic and accelerating until, at the minimum nozzle area (the throat), the flow becomes sonic with M = 1. Since the nozzle starts to diverge, the fluid will continue accelerating until the exit, where it continues as supersonic. The\u00a0Mach number at the end of the nozzle can be calculated in the equations below. The diameters of the end and throat area were converted to Area using formula (1) and compared using formula (2) to find the Mach number using isentropic flow tables.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-157417\" src=\"\/knowledge\/wp-content\/uploads\/sites\/4\/2022\/08\/HM-47.png\" alt=\" width=\"241\" height=\"145\" \/><\/p>\n<p>The resulting Mach number at the end of the nozzle is\u00a0found to be 4.15, which confirms that the exit flow is supersonic.<\/p>\n<hr \/>\n<p><b>Simulation Result<\/b><\/p>\n<p>The Mach number contour confirms that the behaviour at the outflow is supersonic. \u00a0To sufficiently validate the results from the simulation, the maximum Mach number must be compared to the value from the hand calculations. \u00a0The maximum value from the simulation is shown in the &#8216;Summary&#8217; section of the\u00a0Mach Number\u00a0results panel n Discovery AIM.\u00a0The table below compares the calculated value to the value from the simulation. The percentage difference confirms that the simulation result is very accurate, within 5% of the hand calculation.<\/p>\n<table>\n<tbody>\n<tr>\n<td>Pre-Analysis Value<\/td>\n<td>Simulation Value<\/td>\n<td>Percent Difference<\/td>\n<\/tr>\n<tr>\n<td>4.15<\/td>\n<td>4.11<\/td>\n<td>0.96%<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n","protected":false},"template":"","class_list":["post-160177","topic","type-topic","status-publish","hentry","topic-tag-aim-tutotrial","topic-tag-discovery-aim","topic-tag-fluids"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_wp_page_template":["default"],"_bbp_last_active_time":["09-13-2022  20:20:25"],"_bbp_forum_id":["159552"],"_btv_view_count":["2578"],"family":[""],"application_name":[""],"product_version":[""],"_bbp_likes_count":["1"]},"test":"watchlearnansys-com"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/knowledge\/wp-json\/wp\/v2\/topics\/160177","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/innovationspace.ansys.com\/knowledge\/wp-json\/wp\/v2\/topics"}],"about":[{"href":"https:\/\/innovationspace.ansys.com\/knowledge\/wp-json\/wp\/v2\/types\/topic"}],"version-history":[{"count":0,"href":"https:\/\/innovationspace.ansys.com\/knowledge\/wp-json\/wp\/v2\/topics\/160177\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/knowledge\/wp-json\/wp\/v2\/media?parent=160177"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}