{"id":161819,"date":"2023-01-25T07:17:04","date_gmt":"2023-01-25T07:17:04","guid":{"rendered":"\/knowledge\/forums\/topic\/multiphase-model-diverges-right-away-when-using-coupled-with-volume-fractions-option\/"},"modified":"2023-07-31T12:35:57","modified_gmt":"2023-07-31T12:35:57","slug":"multiphase-model-diverges-right-away-when-using-coupled-with-volume-fractions-option","status":"publish","type":"topic","link":"https:\/\/innovationspace.ansys.com\/knowledge\/forums\/topic\/multiphase-model-diverges-right-away-when-using-coupled-with-volume-fractions-option\/","title":{"rendered":"Multiphase model diverges right away when using &#8216;coupled with volume fractions&#8217; option"},"content":{"rendered":"<p>Try first running without this option until converged, then try enabling it. This option is also behaves better when running with decreased URFs for pressure and momentum and higher order discretization. Here are other informative notes from the Fluent user guide regarding lack of convergence with this option:  &#8220;The Coupled with Volume Fractions option (also known as Full Multiphase Coupled in previous ANSYS Fluent versions) couples velocity corrections, shared pressure corrections, and the correction for volume fraction simultaneously. Theoretically, it should be more efficient, however it may have some drawbacks in robustness and CPU time usage. The robustness issue stems from the lack of control of the solution of the volume fraction equation. The continuity constraint (sum of all volume fractions equals 1, and individual values limited between zero and one) cannot be enforced exactly during inner solver iterations, and slight variations from the physical limits may lead to divergence. Research is ongoing in this area to improve the method. The method is advantageous for heterogeneous mass transfer when a low Courant number is given; it also works well in dilute situations.&#8221;<\/p>\n","protected":false},"template":"","class_list":["post-161819","topic","type-topic","status-publish","hentry","topic-tag-19-2","topic-tag-convergence-problems","topic-tag-fluent","topic-tag-fluid-dynamics","topic-tag-mp-eulerian-mp-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=\"Try first running without this option until converged, then try enabling it. This option is also behaves better when running with decreased URFs for pressure and momentum and higher order discretization. Here are other informative notes from the Fluent user guide regarding lack of convergence with this option: &quot;The Coupled with Volume Fractions option (also\" \/>\n\t<meta name=\"robots\" content=\"max-image-preview:large\" \/>\n\t<link rel=\"canonical\" href=\"https:\/\/innovationspace.ansys.com\/knowledge\/forums\/topic\/multiphase-model-diverges-right-away-when-using-coupled-with-volume-fractions-option\/\" \/>\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=\"Multiphase model diverges right away when using \u2018coupled with volume fractions\u2019 option | Ansys Knowledge\" \/>\n\t\t<meta property=\"og:description\" content=\"Try first running without this option until converged, then try enabling it. This option is also behaves better when running with decreased URFs for pressure and momentum and higher order discretization. Here are other informative notes from the Fluent user guide regarding lack of convergence with this option: &quot;The Coupled with Volume Fractions option (also\" \/>\n\t\t<meta property=\"og:url\" content=\"https:\/\/innovationspace.ansys.com\/knowledge\/forums\/topic\/multiphase-model-diverges-right-away-when-using-coupled-with-volume-fractions-option\/\" \/>\n\t\t<meta property=\"article:published_time\" content=\"2023-01-25T07:17:04+00:00\" \/>\n\t\t<meta property=\"article:modified_time\" content=\"2023-07-31T12:35:57+00:00\" \/>\n\t\t<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n\t\t<meta name=\"twitter:title\" content=\"Multiphase model diverges right away when using \u2018coupled with volume fractions\u2019 option | Ansys Knowledge\" \/>\n\t\t<meta name=\"twitter:description\" content=\"Try first running without this option until converged, then try enabling it. This option is also behaves better when running with decreased URFs for pressure and momentum and higher order discretization. Here are other informative notes from the Fluent user guide regarding lack of convergence with this option: &quot;The Coupled with Volume Fractions option (also\" \/>\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\\\/multiphase-model-diverges-right-away-when-using-coupled-with-volume-fractions-option\\\/#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\\\/multiphase-model-diverges-right-away-when-using-coupled-with-volume-fractions-option\\\/#listItem\",\"name\":\"Multiphase model diverges right away when using &#8216;coupled with volume fractions&#8217; option\"},\"previousItem\":{\"@type\":\"ListItem\",\"@id\":\"https:\\\/\\\/innovationspace.ansys.com\\\/knowledge\\\/topics\\\/#listItem\",\"name\":\"Topics\"}},{\"@type\":\"ListItem\",\"@id\":\"https:\\\/\\\/innovationspace.ansys.com\\\/knowledge\\\/forums\\\/topic\\\/multiphase-model-diverges-right-away-when-using-coupled-with-volume-fractions-option\\\/#listItem\",\"position\":4,\"name\":\"Multiphase model diverges right away when using &#8216;coupled with volume fractions&#8217; option\",\"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\\\/multiphase-model-diverges-right-away-when-using-coupled-with-volume-fractions-option\\\/#webpage\",\"url\":\"https:\\\/\\\/innovationspace.ansys.com\\\/knowledge\\\/forums\\\/topic\\\/multiphase-model-diverges-right-away-when-using-coupled-with-volume-fractions-option\\\/\",\"name\":\"Multiphase model diverges right away when using \\u2018coupled with volume fractions\\u2019 option | Ansys Knowledge\",\"description\":\"Try first running without this option until converged, then try enabling it. This option is also behaves better when running with decreased URFs for pressure and momentum and higher order discretization. Here are other informative notes from the Fluent user guide regarding lack of convergence with this option: \\\"The Coupled with Volume Fractions option (also\",\"inLanguage\":\"en-US\",\"isPartOf\":{\"@id\":\"https:\\\/\\\/innovationspace.ansys.com\\\/knowledge\\\/#website\"},\"breadcrumb\":{\"@id\":\"https:\\\/\\\/innovationspace.ansys.com\\\/knowledge\\\/forums\\\/topic\\\/multiphase-model-diverges-right-away-when-using-coupled-with-volume-fractions-option\\\/#breadcrumblist\"},\"datePublished\":\"2023-01-25T07:17:04+00:00\",\"dateModified\":\"2023-07-31T12:35:57+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":"Multiphase model diverges right away when using \u2018coupled with volume fractions\u2019 option | Ansys Knowledge","description":"Try first running without this option until converged, then try enabling it. This option is also behaves better when running with decreased URFs for pressure and momentum and higher order discretization. Here are other informative notes from the Fluent user guide regarding lack of convergence with this option: \"The Coupled with Volume Fractions option (also","canonical_url":"https:\/\/innovationspace.ansys.com\/knowledge\/forums\/topic\/multiphase-model-diverges-right-away-when-using-coupled-with-volume-fractions-option\/","robots":"max-image-preview:large","keywords":"","webmasterTools":{"miscellaneous":""},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"BreadcrumbList","@id":"https:\/\/innovationspace.ansys.com\/knowledge\/forums\/topic\/multiphase-model-diverges-right-away-when-using-coupled-with-volume-fractions-option\/#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\/multiphase-model-diverges-right-away-when-using-coupled-with-volume-fractions-option\/#listItem","name":"Multiphase model diverges right away when using &#8216;coupled with volume fractions&#8217; option"},"previousItem":{"@type":"ListItem","@id":"https:\/\/innovationspace.ansys.com\/knowledge\/topics\/#listItem","name":"Topics"}},{"@type":"ListItem","@id":"https:\/\/innovationspace.ansys.com\/knowledge\/forums\/topic\/multiphase-model-diverges-right-away-when-using-coupled-with-volume-fractions-option\/#listItem","position":4,"name":"Multiphase model diverges right away when using &#8216;coupled with volume fractions&#8217; option","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\/multiphase-model-diverges-right-away-when-using-coupled-with-volume-fractions-option\/#webpage","url":"https:\/\/innovationspace.ansys.com\/knowledge\/forums\/topic\/multiphase-model-diverges-right-away-when-using-coupled-with-volume-fractions-option\/","name":"Multiphase model diverges right away when using \u2018coupled with volume fractions\u2019 option | Ansys Knowledge","description":"Try first running without this option until converged, then try enabling it. This option is also behaves better when running with decreased URFs for pressure and momentum and higher order discretization. Here are other informative notes from the Fluent user guide regarding lack of convergence with this option: \"The Coupled with Volume Fractions option (also","inLanguage":"en-US","isPartOf":{"@id":"https:\/\/innovationspace.ansys.com\/knowledge\/#website"},"breadcrumb":{"@id":"https:\/\/innovationspace.ansys.com\/knowledge\/forums\/topic\/multiphase-model-diverges-right-away-when-using-coupled-with-volume-fractions-option\/#breadcrumblist"},"datePublished":"2023-01-25T07:17:04+00:00","dateModified":"2023-07-31T12:35:57+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":"Multiphase model diverges right away when using \u2018coupled with volume fractions\u2019 option | Ansys Knowledge","og:description":"Try first running without this option until converged, then try enabling it. This option is also behaves better when running with decreased URFs for pressure and momentum and higher order discretization. Here are other informative notes from the Fluent user guide regarding lack of convergence with this option: &quot;The Coupled with Volume Fractions option (also","og:url":"https:\/\/innovationspace.ansys.com\/knowledge\/forums\/topic\/multiphase-model-diverges-right-away-when-using-coupled-with-volume-fractions-option\/","article:published_time":"2023-01-25T07:17:04+00:00","article:modified_time":"2023-07-31T12:35:57+00:00","twitter:card":"summary_large_image","twitter:title":"Multiphase model diverges right away when using \u2018coupled with volume fractions\u2019 option | Ansys Knowledge","twitter:description":"Try first running without this option until converged, then try enabling it. This option is also behaves better when running with decreased URFs for pressure and momentum and higher order discretization. Here are other informative notes from the Fluent user guide regarding lack of convergence with this option: &quot;The Coupled with Volume Fractions option (also"},"aioseo_meta_data":{"post_id":"161819","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 19:25:43","updated":"2026-07-29 06:17:31","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\tMultiphase model diverges right away when using \u2018coupled with volume fractions\u2019 option\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":"Multiphase model diverges right away when using &#8216;coupled with volume fractions&#8217; option","link":"https:\/\/innovationspace.ansys.com\/knowledge\/forums\/topic\/multiphase-model-diverges-right-away-when-using-coupled-with-volume-fractions-option\/"}],"acf":[],"custom_fields":[{"0":{"_wp_page_template":["default"],"_bbp_forum_id":["27809"],"_bbp_author_ip":["23.56.168.180"],"_bbp_last_active_time":["1-24-2023  20:20:19"],"_btv_view_count":["4835"],"siebel_km_number":["2056606"],"product_version":["19.2"],"km_published_date":["2018-10-10T05:07:38.000Z"],"family":["Fluid Dynamics"],"application_name":["FLUENT"]},"test":"articlesansys-com"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/knowledge\/wp-json\/wp\/v2\/topics\/161819","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\/161819\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/knowledge\/wp-json\/wp\/v2\/media?parent=161819"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}