{"id":453489,"date":"2026-02-28T23:45:34","date_gmt":"2026-02-28T23:45:34","guid":{"rendered":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/how-to-create-a-porous-jump-surface\/"},"modified":"2026-02-28T23:45:34","modified_gmt":"2026-02-28T23:45:34","slug":"how-to-create-a-porous-jump-surface","status":"publish","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/how-to-create-a-porous-jump-surface\/","title":{"rendered":"How to create a porous jump surface?"},"content":{"rendered":"<p>&lt;p&gt;Hi,&lt;\/p&gt;&lt;p&gt;I&rsquo;m running ANSYS Fluent 2025 R2 with Fluent Meshing &rarr; Watertight Geometry Workflow only (university license). I&rsquo;m simulating VOF free-surface (air\/water, open-channel) flow through a plastic collection net (fishing net basically)+flow around floating solid to measure the drag. I need to model a thin net panel inside the fluid domain as a Porous Jump (pressure loss only), but the panel is internal (does not touch outer boundaries).&lt;\/p&gt;&lt;p&gt;&nbsp;&lt;\/p&gt;&lt;p&gt;Problem: I struggle to create a robust porous-jump setup without the case failing. To assign porous jump, I tried:&lt;\/p&gt;&lt;p&gt;&nbsp;&lt;\/p&gt;<\/p>\n<ul>\n<li>splitting the fluid domain into 2 volumes and using the split plane as internal,<\/li>\n<li>imprinting\/splitting the net patch on the internal plane,<\/li>\n<li>applying share topology \/ joining, etc.<\/li>\n<\/ul>\n<p>&lt;p&gt;&nbsp;&lt;\/p&gt;&lt;p&gt;&nbsp;&lt;\/p&gt;&lt;p&gt;But I often get &ldquo;pairs not joined&rdquo; on the internal interface, zones disappear\/merge after meshing, and porous-jump ends up as a wall or cannot be assigned cleanly.&lt;\/p&gt;&lt;p&gt;&nbsp;&lt;\/p&gt;&lt;p&gt;Question: What is the recommended, fail-safe workflow in Watertight Geometry to create an internal surface for a net and assign it as Porous Jump for VOF open-channel cases?&lt;\/p&gt;&lt;p&gt;Specifically: should this be done as a baffle (wall + shadow), an internal face zone, or by splitting into two cell zones and making a mesh interface&mdash;what&rsquo;s the most robust method in Fluent 2025 R2 which later also doesn&#8217;t cause solver issues ?&lt;\/p&gt;&lt;p&gt;&nbsp;&lt;\/p&gt;&lt;p&gt;Thanks!&lt;\/p&gt;<\/p>\n","protected":false},"template":"","class_list":["post-453489","topic","type-topic","status-publish","hentry","topic-tag-porous-jump","topic-tag-porous-media"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_forum_id":["27792"],"_bbp_topic_id":["453489"],"_bbp_author_ip":["2a09:bac3:382c:26c8::3dd:31"],"_bbp_last_reply_id":["454605"],"_bbp_last_active_id":["454605"],"_bbp_last_active_time":["2026-03-16 15:19:16"],"_bbp_reply_count":["1"],"_bbp_reply_count_hidden":["0"],"_bbp_voice_count":["2"],"_bbp_engagement":["657738","629050"],"_btv_view_count":["112"],"_bbp_topic_status":["unanswered"],"_bbp_subscription":["629050"]},"test":"2mudrt52solent-ac-uk"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/453489","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":0,"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/453489\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=453489"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}