{"id":44171,"date":"2020-05-19T19:27:20","date_gmt":"2020-05-19T19:27:20","guid":{"rendered":"\/forum\/forums\/topic\/getting-a-plug-flow-when-implementing-a-parabolic-velocity-profile-udf-in-a-3d-pipe\/"},"modified":"2020-05-19T19:27:20","modified_gmt":"2020-05-19T19:27:20","slug":"getting-a-plug-flow-when-implementing-a-parabolic-velocity-profile-udf-in-a-3d-pipe","status":"closed","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/getting-a-plug-flow-when-implementing-a-parabolic-velocity-profile-udf-in-a-3d-pipe\/","title":{"rendered":"getting a plug flow when implementing a parabolic velocity profile UDF in a 3D pipe"},"content":{"rendered":"

Hi everyone,<\/p>\n

<\/p>\n

I’m trying to implement a parabolic velocity profile at the inlet of a 3D pipe (for a steady flow case), the inlet itself is not perpendicular to any of the primary axes.<\/p>\n

<\/p>\n

I used the following UDF:<\/p>\n

<\/p>\n

\"\"<\/p>\n

<\/p>\n

After running the simulation, the result was a plug flow at the inlet of 7.07[m\/s] as I implemented instead of parabolic profile. Furthermore, changing the radius units to [m] led to non-converged solution. I also tried implementing the UDF as a velocity magnitude (which gave a plug flow that developed to parabolic at the outlet) and as an axial velocity in cylindrical coordinates (gave reversed flow for all iterations). <\/p>\n

<\/p>\n

I’ve tried other manipulations but nothing worked.<\/p>\n

<\/p>\n

Finally, the easiest way to deal with this situation is to elongate the pipe and insert a constant velocity, then get the profile to develop, but in this case, the profile I get is not precise enough, Not to mention that it takes additional computational time which I’m trying to avoid due the complex geometry. <\/p>\n

<\/p>\n

I’d appreciate your help,<\/p>\n

<\/p>\n

Thanks,<\/p>\n","protected":false},"template":"","class_list":["post-44171","topic","type-topic","status-closed","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\n\t\t\n\t\t\n\t\t