{"id":390130,"date":"2024-10-16T23:22:18","date_gmt":"2024-10-16T23:22:18","guid":{"rendered":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/boundary-condition-issue\/"},"modified":"2024-10-16T23:22:18","modified_gmt":"2024-10-16T23:22:18","slug":"boundary-condition-issue","status":"publish","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/boundary-condition-issue\/","title":{"rendered":"Boundary Condition Issue"},"content":{"rendered":"

<div id=”UniqueMessageBody_61″ class=”XbIp4 jmmB7 GNqVo allowTextSelection OuGoX” style=”background-color: white; color: black;” tabindex=”0″ aria-label=”Message body”><div><div><div lang=”en-US” style=”word-wrap: break-word;”><div><p style=”font-size: 12pt; font-family: Aptos,sans-serif; margin: 0;”><span style=”font-size: 12pt;”>I am attempting to simulate the flow of resin through a rectangular porous domain using Ansys Fluent. The flow is driven by a pressure difference, with atmospheric pressure at the inlet and a very low pressure at the outlet. Initially, the velocity throughout the domain is zero. The inlet pressure is set to 101,325 Pa (atmospheric pressure), while the outlet pressure is set to 2 Pa. This pressure gradient initiates the flow through the porous medium.<\/span><\/p><p style=”font-size: 12pt; font-family: Aptos,sans-serif; margin: 0;”><span style=”font-size: 12pt;”> <\/span><\/p><p style=”font-size: 12pt; font-family: Aptos,sans-serif; margin: 0;”><span style=”font-size: 12pt;”>However, when I specify pressure inlet and pressure outlet boundary conditions, Fluent crashes. I have tried various pressure initializations within the domain, including:<\/span><\/p><\/p>\n

    <li style=”font-size: 12pt; font-family: Aptos,sans-serif; margin: 0;”><span style=”font-size: 12pt;”>Atmospheric pressure,<\/span><\/li>\n

    <li style=”font-size: 12pt; font-family: Aptos,sans-serif; margin: 0;”><span style=”font-size: 12pt;”>Exit pressure (2 Pa),<\/span><\/li>\n

    <li style=”font-size: 12pt; font-family: Aptos,sans-serif; margin: 0;”><span style=”font-size: 12pt;”>A linear variation from the inlet to the outlet.<\/span><\/li>\n<\/ol>\n

    <p style=”font-size: 12pt; font-family: Aptos,sans-serif; margin: 0;”><span style=”font-size: 12pt;”>Unfortunately, none of these approaches worked.<\/span><\/p><p style=”font-size: 12pt; font-family: Aptos,sans-serif; margin: 0;”><span style=”font-size: 12pt;”> <\/span><\/p><p style=”font-size: 12pt; font-family: Aptos,sans-serif; margin: 0;”><span style=”font-size: 12pt;”>Interestingly, when I specify a velocity inlet condition (with the inlet velocity calculated based on Darcy’s law), the simulation runs successfully. However, the inlet velocity is not constant in reality, as it should vary based on the pressure gradient. Therefore, I would prefer to model the flow using specified inlet and outlet pressures rather than a constant velocity.<\/span><\/p><p style=”font-size: 12pt; font-family: Aptos,sans-serif; margin: 0;”><span style=”font-size: 12pt;”> <\/span><\/p><p style=”font-size: 12pt; font-family: Aptos,sans-serif; margin: 0;”><span style=”font-size: 12pt;”>The mesh employed is a Cartesian mesh. Any advice or pointers on how to properly model flows with specified inlet and outlet pressures in Fluent would be greatly appreciated.<\/span><\/p><\/div><\/div><\/div><\/div><\/div><p> <\/p><p> <\/p><p> <\/p><p> <\/p><\/p>\n","protected":false},"template":"","class_list":["post-390130","topic","type-topic","status-publish","hentry"],"aioseo_notices":[],"aioseo_head":"\n\t\t\n\t\n\t\n\t\n\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t