{"id":167038,"date":"2023-04-05T14:32:45","date_gmt":"2023-04-05T14:32:45","guid":{"rendered":"\/knowledge\/forums\/topic\/why-does-my-external-flow-vof-dpm-simulation-exhibit-extremely-high-velocities-in-the-far-field\/"},"modified":"2023-07-31T12:27:52","modified_gmt":"2023-07-31T12:27:52","slug":"why-does-my-external-flow-vof-dpm-simulation-exhibit-extremely-high-velocities-in-the-far-field","status":"publish","type":"topic","link":"https:\/\/innovationspace.ansys.com\/knowledge\/forums\/topic\/why-does-my-external-flow-vof-dpm-simulation-exhibit-extremely-high-velocities-in-the-far-field\/","title":{"rendered":"Why does my external flow VOF DPM simulation exhibit extremely high velocities in the far field?"},"content":{"rendered":"<p>Like any other external flow simulation, the placement of far-field boundaries for these cases is critical.  Placement may be even more critical for VOF DPM because of the density changes that occur during phase change.  Care must be taken that the far field boundaries are placed far enough away from the object of interest.  If the far field boundaries are placed too close, the pressure boundary conditions that they impose will start to influence the flow field around the object of interest and constrain it in a non-physical way.  Below are some rules of thumb for far field boundary placement that can be applied to VOF-DPM and other classes of external flow problems:   A standing obstruction with height H &#038; width W, should have farfield boundaries at at least 5H and 10W wide.  The upstream should allow at least 2H of flow development and at least 10H downstream for the wake.  For airfoils, the domain shape should be parabolic, with dimensions that depend on the airfoil size.   The inflow should be at a distance of at least 10 chords upstream and the domains should extend 15 chordlengths downstream past the trailing edge.<\/p>\n","protected":false},"template":"","class_list":["post-167038","topic","type-topic","status-publish","hentry","topic-tag-19-1","topic-tag-fluent","topic-tag-fluid-dynamics","topic-tag-modeling-setup-advice","topic-tag-mp-free-surface-flow","topic-tag-multiphase"],"aioseo_notices":[],"aioseo_head":"\n\t\t<!-- All in One SEO 4.9.10 - aioseo.com -->\n\t<meta name=\"description\" content=\"Like any other external flow simulation, the placement of far-field boundaries for these cases is critical. Placement may be even more critical for VOF DPM because of the density changes that occur during phase change. Care must be taken that the far field boundaries are placed far enough away from the object of interest. If\" \/>\n\t<meta name=\"robots\" content=\"max-image-preview:large\" \/>\n\t<link rel=\"canonical\" href=\"https:\/\/innovationspace.ansys.com\/knowledge\/forums\/topic\/why-does-my-external-flow-vof-dpm-simulation-exhibit-extremely-high-velocities-in-the-far-field\/\" \/>\n\t<meta name=\"generator\" content=\"All in One SEO (AIOSEO) 4.9.10\" \/>\n\t\t<meta property=\"og:locale\" content=\"en_US\" \/>\n\t\t<meta property=\"og:site_name\" content=\"Ansys Knowledge | Ansys Innovation Space\" \/>\n\t\t<meta property=\"og:type\" content=\"article\" \/>\n\t\t<meta property=\"og:title\" content=\"Why does my external flow VOF DPM simulation exhibit extremely high velocities in the far field? | Ansys Knowledge\" \/>\n\t\t<meta property=\"og:description\" content=\"Like any other external flow simulation, the placement of far-field boundaries for these cases is critical. Placement may be even more critical for VOF DPM because of the density changes that occur during phase change. Care must be taken that the far field boundaries are placed far enough away from the object of interest. If\" \/>\n\t\t<meta property=\"og:url\" content=\"https:\/\/innovationspace.ansys.com\/knowledge\/forums\/topic\/why-does-my-external-flow-vof-dpm-simulation-exhibit-extremely-high-velocities-in-the-far-field\/\" \/>\n\t\t<meta property=\"article:published_time\" content=\"2023-04-05T14:32:45+00:00\" \/>\n\t\t<meta property=\"article:modified_time\" content=\"2023-07-31T12:27:52+00:00\" \/>\n\t\t<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n\t\t<meta name=\"twitter:title\" content=\"Why does my external flow VOF DPM simulation exhibit extremely high velocities in the far field? | Ansys Knowledge\" \/>\n\t\t<meta name=\"twitter:description\" content=\"Like any other external flow simulation, the placement of far-field boundaries for these cases is critical. Placement may be even more critical for VOF DPM because of the density changes that occur during phase change. Care must be taken that the far field boundaries are placed far enough away from the object of interest. If\" \/>\n\t\t<script type=\"application\/ld+json\" class=\"aioseo-schema\">\n\t\t\t{\"@context\":\"https:\\\/\\\/schema.org\",\"@graph\":[{\"@type\":\"BreadcrumbList\",\"@id\":\"https:\\\/\\\/innovationspace.ansys.com\\\/knowledge\\\/forums\\\/topic\\\/why-does-my-external-flow-vof-dpm-simulation-exhibit-extremely-high-velocities-in-the-far-field\\\/#breadcrumblist\",\"itemListElement\":[{\"@type\":\"ListItem\",\"@id\":\"https:\\\/\\\/innovationspace.ansys.com\\\/knowledge#listItem\",\"position\":1,\"name\":\"Home\",\"item\":\"https:\\\/\\\/innovationspace.ansys.com\\\/knowledge\",\"nextItem\":{\"@type\":\"ListItem\",\"@id\":\"https:\\\/\\\/innovationspace.ansys.com\\\/knowledge\\\/topics\\\/#listItem\",\"name\":\"Topics\"}},{\"@type\":\"ListItem\",\"@id\":\"https:\\\/\\\/innovationspace.ansys.com\\\/knowledge\\\/topics\\\/#listItem\",\"position\":2,\"name\":\"Topics\",\"item\":\"https:\\\/\\\/innovationspace.ansys.com\\\/knowledge\\\/topics\\\/\",\"nextItem\":{\"@type\":\"ListItem\",\"@id\":\"https:\\\/\\\/innovationspace.ansys.com\\\/knowledge\\\/forums\\\/topic-tag\\\/fluent\\\/#listItem\",\"name\":\"fluent\"},\"previousItem\":{\"@type\":\"ListItem\",\"@id\":\"https:\\\/\\\/innovationspace.ansys.com\\\/knowledge#listItem\",\"name\":\"Home\"}},{\"@type\":\"ListItem\",\"@id\":\"https:\\\/\\\/innovationspace.ansys.com\\\/knowledge\\\/forums\\\/topic-tag\\\/fluent\\\/#listItem\",\"position\":3,\"name\":\"fluent\",\"item\":\"https:\\\/\\\/innovationspace.ansys.com\\\/knowledge\\\/forums\\\/topic-tag\\\/fluent\\\/\",\"nextItem\":{\"@type\":\"ListItem\",\"@id\":\"https:\\\/\\\/innovationspace.ansys.com\\\/knowledge\\\/forums\\\/topic\\\/why-does-my-external-flow-vof-dpm-simulation-exhibit-extremely-high-velocities-in-the-far-field\\\/#listItem\",\"name\":\"Why does my external flow VOF DPM simulation exhibit extremely high velocities in the far field?\"},\"previousItem\":{\"@type\":\"ListItem\",\"@id\":\"https:\\\/\\\/innovationspace.ansys.com\\\/knowledge\\\/topics\\\/#listItem\",\"name\":\"Topics\"}},{\"@type\":\"ListItem\",\"@id\":\"https:\\\/\\\/innovationspace.ansys.com\\\/knowledge\\\/forums\\\/topic\\\/why-does-my-external-flow-vof-dpm-simulation-exhibit-extremely-high-velocities-in-the-far-field\\\/#listItem\",\"position\":4,\"name\":\"Why does my external flow VOF DPM simulation exhibit extremely high velocities in the far field?\",\"previousItem\":{\"@type\":\"ListItem\",\"@id\":\"https:\\\/\\\/innovationspace.ansys.com\\\/knowledge\\\/forums\\\/topic-tag\\\/fluent\\\/#listItem\",\"name\":\"fluent\"}}]},{\"@type\":\"Organization\",\"@id\":\"https:\\\/\\\/innovationspace.ansys.com\\\/knowledge\\\/#organization\",\"name\":\"Ansys Knowledge\",\"description\":\"Ansys Innovation Space\",\"url\":\"https:\\\/\\\/innovationspace.ansys.com\\\/knowledge\\\/\"},{\"@type\":\"WebPage\",\"@id\":\"https:\\\/\\\/innovationspace.ansys.com\\\/knowledge\\\/forums\\\/topic\\\/why-does-my-external-flow-vof-dpm-simulation-exhibit-extremely-high-velocities-in-the-far-field\\\/#webpage\",\"url\":\"https:\\\/\\\/innovationspace.ansys.com\\\/knowledge\\\/forums\\\/topic\\\/why-does-my-external-flow-vof-dpm-simulation-exhibit-extremely-high-velocities-in-the-far-field\\\/\",\"name\":\"Why does my external flow VOF DPM simulation exhibit extremely high velocities in the far field? | Ansys Knowledge\",\"description\":\"Like any other external flow simulation, the placement of far-field boundaries for these cases is critical. Placement may be even more critical for VOF DPM because of the density changes that occur during phase change. Care must be taken that the far field boundaries are placed far enough away from the object of interest. If\",\"inLanguage\":\"en-US\",\"isPartOf\":{\"@id\":\"https:\\\/\\\/innovationspace.ansys.com\\\/knowledge\\\/#website\"},\"breadcrumb\":{\"@id\":\"https:\\\/\\\/innovationspace.ansys.com\\\/knowledge\\\/forums\\\/topic\\\/why-does-my-external-flow-vof-dpm-simulation-exhibit-extremely-high-velocities-in-the-far-field\\\/#breadcrumblist\"},\"datePublished\":\"2023-04-05T14:32:45+00:00\",\"dateModified\":\"2023-07-31T12:27:52+00:00\"},{\"@type\":\"WebSite\",\"@id\":\"https:\\\/\\\/innovationspace.ansys.com\\\/knowledge\\\/#website\",\"url\":\"https:\\\/\\\/innovationspace.ansys.com\\\/knowledge\\\/\",\"name\":\"Ansys Knowledge\",\"description\":\"Ansys Innovation Space\",\"inLanguage\":\"en-US\",\"publisher\":{\"@id\":\"https:\\\/\\\/innovationspace.ansys.com\\\/knowledge\\\/#organization\"}}]}\n\t\t<\/script>\n\t\t<!-- All in One SEO -->\n\n","aioseo_head_json":{"title":"Why does my external flow VOF DPM simulation exhibit extremely high velocities in the far field? | Ansys Knowledge","description":"Like any other external flow simulation, the placement of far-field boundaries for these cases is critical. Placement may be even more critical for VOF DPM because of the density changes that occur during phase change. Care must be taken that the far field boundaries are placed far enough away from the object of interest. If","canonical_url":"https:\/\/innovationspace.ansys.com\/knowledge\/forums\/topic\/why-does-my-external-flow-vof-dpm-simulation-exhibit-extremely-high-velocities-in-the-far-field\/","robots":"max-image-preview:large","keywords":"","webmasterTools":{"miscellaneous":""},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"BreadcrumbList","@id":"https:\/\/innovationspace.ansys.com\/knowledge\/forums\/topic\/why-does-my-external-flow-vof-dpm-simulation-exhibit-extremely-high-velocities-in-the-far-field\/#breadcrumblist","itemListElement":[{"@type":"ListItem","@id":"https:\/\/innovationspace.ansys.com\/knowledge#listItem","position":1,"name":"Home","item":"https:\/\/innovationspace.ansys.com\/knowledge","nextItem":{"@type":"ListItem","@id":"https:\/\/innovationspace.ansys.com\/knowledge\/topics\/#listItem","name":"Topics"}},{"@type":"ListItem","@id":"https:\/\/innovationspace.ansys.com\/knowledge\/topics\/#listItem","position":2,"name":"Topics","item":"https:\/\/innovationspace.ansys.com\/knowledge\/topics\/","nextItem":{"@type":"ListItem","@id":"https:\/\/innovationspace.ansys.com\/knowledge\/forums\/topic-tag\/fluent\/#listItem","name":"fluent"},"previousItem":{"@type":"ListItem","@id":"https:\/\/innovationspace.ansys.com\/knowledge#listItem","name":"Home"}},{"@type":"ListItem","@id":"https:\/\/innovationspace.ansys.com\/knowledge\/forums\/topic-tag\/fluent\/#listItem","position":3,"name":"fluent","item":"https:\/\/innovationspace.ansys.com\/knowledge\/forums\/topic-tag\/fluent\/","nextItem":{"@type":"ListItem","@id":"https:\/\/innovationspace.ansys.com\/knowledge\/forums\/topic\/why-does-my-external-flow-vof-dpm-simulation-exhibit-extremely-high-velocities-in-the-far-field\/#listItem","name":"Why does my external flow VOF DPM simulation exhibit extremely high velocities in the far field?"},"previousItem":{"@type":"ListItem","@id":"https:\/\/innovationspace.ansys.com\/knowledge\/topics\/#listItem","name":"Topics"}},{"@type":"ListItem","@id":"https:\/\/innovationspace.ansys.com\/knowledge\/forums\/topic\/why-does-my-external-flow-vof-dpm-simulation-exhibit-extremely-high-velocities-in-the-far-field\/#listItem","position":4,"name":"Why does my external flow VOF DPM simulation exhibit extremely high velocities in the far field?","previousItem":{"@type":"ListItem","@id":"https:\/\/innovationspace.ansys.com\/knowledge\/forums\/topic-tag\/fluent\/#listItem","name":"fluent"}}]},{"@type":"Organization","@id":"https:\/\/innovationspace.ansys.com\/knowledge\/#organization","name":"Ansys Knowledge","description":"Ansys Innovation Space","url":"https:\/\/innovationspace.ansys.com\/knowledge\/"},{"@type":"WebPage","@id":"https:\/\/innovationspace.ansys.com\/knowledge\/forums\/topic\/why-does-my-external-flow-vof-dpm-simulation-exhibit-extremely-high-velocities-in-the-far-field\/#webpage","url":"https:\/\/innovationspace.ansys.com\/knowledge\/forums\/topic\/why-does-my-external-flow-vof-dpm-simulation-exhibit-extremely-high-velocities-in-the-far-field\/","name":"Why does my external flow VOF DPM simulation exhibit extremely high velocities in the far field? | Ansys Knowledge","description":"Like any other external flow simulation, the placement of far-field boundaries for these cases is critical. Placement may be even more critical for VOF DPM because of the density changes that occur during phase change. Care must be taken that the far field boundaries are placed far enough away from the object of interest. If","inLanguage":"en-US","isPartOf":{"@id":"https:\/\/innovationspace.ansys.com\/knowledge\/#website"},"breadcrumb":{"@id":"https:\/\/innovationspace.ansys.com\/knowledge\/forums\/topic\/why-does-my-external-flow-vof-dpm-simulation-exhibit-extremely-high-velocities-in-the-far-field\/#breadcrumblist"},"datePublished":"2023-04-05T14:32:45+00:00","dateModified":"2023-07-31T12:27:52+00:00"},{"@type":"WebSite","@id":"https:\/\/innovationspace.ansys.com\/knowledge\/#website","url":"https:\/\/innovationspace.ansys.com\/knowledge\/","name":"Ansys Knowledge","description":"Ansys Innovation Space","inLanguage":"en-US","publisher":{"@id":"https:\/\/innovationspace.ansys.com\/knowledge\/#organization"}}]},"og:locale":"en_US","og:site_name":"Ansys Knowledge | Ansys Innovation Space","og:type":"article","og:title":"Why does my external flow VOF DPM simulation exhibit extremely high velocities in the far field? | Ansys Knowledge","og:description":"Like any other external flow simulation, the placement of far-field boundaries for these cases is critical. Placement may be even more critical for VOF DPM because of the density changes that occur during phase change. Care must be taken that the far field boundaries are placed far enough away from the object of interest. If","og:url":"https:\/\/innovationspace.ansys.com\/knowledge\/forums\/topic\/why-does-my-external-flow-vof-dpm-simulation-exhibit-extremely-high-velocities-in-the-far-field\/","article:published_time":"2023-04-05T14:32:45+00:00","article:modified_time":"2023-07-31T12:27:52+00:00","twitter:card":"summary_large_image","twitter:title":"Why does my external flow VOF DPM simulation exhibit extremely high velocities in the far field? | Ansys Knowledge","twitter:description":"Like any other external flow simulation, the placement of far-field boundaries for these cases is critical. Placement may be even more critical for VOF DPM because of the density changes that occur during phase change. Care must be taken that the far field boundaries are placed far enough away from the object of interest. If"},"aioseo_meta_data":{"post_id":"167038","title":null,"description":null,"keywords":null,"keyphrases":null,"primary_term":null,"canonical_url":null,"og_title":null,"og_description":null,"og_object_type":"default","og_image_type":"default","og_image_url":null,"og_image_width":null,"og_image_height":null,"og_image_custom_url":null,"og_image_custom_fields":null,"og_video":null,"og_custom_url":null,"og_article_section":null,"og_article_tags":null,"twitter_use_og":false,"twitter_card":"default","twitter_image_type":"default","twitter_image_url":null,"twitter_image_custom_url":null,"twitter_image_custom_fields":null,"twitter_title":null,"twitter_description":null,"schema":{"blockGraphs":[],"customGraphs":[],"default":{"data":{"Article":[],"Course":[],"Dataset":[],"FAQPage":[],"Movie":[],"Person":[],"Product":[],"ProductReview":[],"Car":[],"Recipe":[],"Service":[],"SoftwareApplication":[],"WebPage":[]},"graphName":"","isEnabled":true},"graphs":[]},"schema_type":"default","schema_type_options":null,"pillar_content":false,"robots_default":true,"robots_noindex":false,"robots_noarchive":false,"robots_nosnippet":false,"robots_nofollow":false,"robots_noimageindex":false,"robots_noodp":false,"robots_notranslate":false,"robots_max_snippet":null,"robots_max_videopreview":null,"robots_max_imagepreview":"large","priority":null,"frequency":null,"local_seo":null,"limit_modified_date":false,"created":"2025-10-17 23:29:49","updated":"2026-07-29 21:13:15","ai":null,"breadcrumb_settings":null,"seo_analyzer_scan_date":null},"aioseo_breadcrumb":"<div class=\"aioseo-breadcrumbs\"><span class=\"aioseo-breadcrumb\">\n\t\t\t<a href=\"https:\/\/innovationspace.ansys.com\/knowledge\" title=\"Home\">Home<\/a>\n\t\t<\/span><span class=\"aioseo-breadcrumb-separator\">&raquo;<\/span><span class=\"aioseo-breadcrumb\">\n\t\t\t<a href=\"https:\/\/innovationspace.ansys.com\/knowledge\/topics\/\" title=\"Topics\">Topics<\/a>\n\t\t<\/span><span class=\"aioseo-breadcrumb-separator\">&raquo;<\/span><span class=\"aioseo-breadcrumb\">\n\t\t\t<a href=\"https:\/\/innovationspace.ansys.com\/knowledge\/forums\/topic-tag\/fluent\/\" title=\"fluent\">fluent<\/a>\n\t\t<\/span><span class=\"aioseo-breadcrumb-separator\">&raquo;<\/span><span class=\"aioseo-breadcrumb\">\n\t\t\tWhy does my external flow VOF DPM simulation exhibit extremely high velocities in the far field?\n\t\t<\/span><\/div>","aioseo_breadcrumb_json":[{"label":"Home","link":"https:\/\/innovationspace.ansys.com\/knowledge"},{"label":"Topics","link":"https:\/\/innovationspace.ansys.com\/knowledge\/topics\/"},{"label":"fluent","link":"https:\/\/innovationspace.ansys.com\/knowledge\/forums\/topic-tag\/fluent\/"},{"label":"Why does my external flow VOF DPM simulation exhibit extremely high velocities in the far field?","link":"https:\/\/innovationspace.ansys.com\/knowledge\/forums\/topic\/why-does-my-external-flow-vof-dpm-simulation-exhibit-extremely-high-velocities-in-the-far-field\/"}],"acf":[],"custom_fields":[{"0":{"_wp_page_template":["default"],"_bbp_last_active_time":["5\/4\/2023 20:20"],"_bbp_forum_id":["27809"],"_bbp_author_ip":["209.182.204.162"],"_btv_view_count":["1100"],"siebel_km_number":["2056016"],"product_version":["19.1"],"km_published_date":["2018-08-20T00:00:00.000Z"],"family":["Fluid Dynamics"],"application_name":["FLUENT"]},"test":"articlesansys-com"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/knowledge\/wp-json\/wp\/v2\/topics\/167038","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\/167038\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/knowledge\/wp-json\/wp\/v2\/media?parent=167038"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}