{"id":428989,"date":"2025-04-15T11:25:32","date_gmt":"2025-04-15T11:25:32","guid":{"rendered":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/reverse-flow-2\/"},"modified":"2025-04-15T11:25:32","modified_gmt":"2025-04-15T11:25:32","slug":"reverse-flow-2","status":"publish","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/reverse-flow-2\/","title":{"rendered":"Reverse flow"},"content":{"rendered":"<p>&lt;div class=&#8221;mx-name-container13 hover-trigger&#8221;&gt;&lt;div class=&#8221;mx-name-container11&#8243;&gt;&lt;div class=&#8221;mx-name-container1&#8243;&gt;&lt;div class=&#8221;mx-name-layoutGrid2 mx-layoutgrid mx-layoutgrid-fluid&#8221;&gt;&lt;div class=&#8221;row&#8221;&gt;&lt;div class=&#8221;col-lg-9 col-md col&#8221;&gt;&lt;div class=&#8221;mx-name-markdownViewer1 clipboard spacing-outer-bottom-none form-group no-columns&#8221;&gt;&lt;div class=&#8221;widget-markdown&#8221;&gt;&lt;p&gt;Hello,&lt;\/p&gt;&lt;p&gt;I am simulating a battery pack cooled by PCM (Phase Change Material) and liquid cooling. I aim to implement a delayed boundary condition where the velocity inlet boundary condition is activated only when the PCM liquid fraction reaches 0.6. For the liquid cooling setup, I have applied velocity inlet and pressure outlet boundary conditions. To achieve the delayed boundary condition, I used expressions to define the boundary condition.&lt;\/p&gt;&lt;p&gt;The issue I am facing is that the velocity is initially set to zero, which leads to reverse flow occurring in the channel&mdash;a behavior that should not happen. I need to ensure that no flow occurs in the channel until the velocity inlet boundary condition is triggered. I have also tried using an outflow boundary condition instead of a pressure outlet, but the problem persists. Additionally, I experimented with mass flow inlet and mass flow outlet boundary conditions, but the issue remains unresolved.&lt;\/p&gt;&lt;p&gt;Could someone please help me in solving this issue?&lt;\/p&gt;&lt;p&gt;Thank you!&lt;\/p&gt;&lt;\/div&gt;&lt;\/div&gt;&lt;\/div&gt;&lt;div class=&#8221;col-lg-3 col-md col&#8221;&gt;&nbsp;&lt;\/div&gt;&lt;\/div&gt;&lt;\/div&gt;&lt;\/div&gt;&lt;\/div&gt;&lt;\/div&gt;<\/p>\n","protected":false},"template":"","class_list":["post-428989","topic","type-topic","status-publish","hentry","topic-tag-fluent-cfd-ansys-1","topic-tag-battery-simulation","topic-tag-boundary-condition","topic-tag-fluent","topic-tag-reverse-flow-2","topic-tag-reversed-flow"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_forum_id":["27792"],"_bbp_topic_id":["428989"],"_bbp_subscription":["423403","199"],"_bbp_author_ip":["136.226.254.176"],"_bbp_last_reply_id":["429113"],"_bbp_last_active_id":["429113"],"_bbp_last_active_time":["2025-04-16 08:52:15"],"_bbp_reply_count":["9"],"_bbp_reply_count_hidden":["0"],"_bbp_voice_count":["2"],"_bbp_engagement":["423403","199"],"_btv_view_count":["142"],"_bbp_topic_status":["unanswered"],"_bbp_likes_count":["0"]},"test":"177790e3c1b2a6ee8923405aca6c90e2c1cc0f5a"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/428989","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\/428989\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=428989"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}