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I am currently working on a CFD project using Ansys Fluent 2025 R1. My goal is to apply the outlet flow field from a long straight pipe simulation as the inlet boundary condition for a subsequent curved pipe simulation.

• For steady-state cases, I have successfully exported the outlet velocity profile and then applied it as the inlet condition of the curved pipe.

• However, in the transient case, I am struggling to find the proper way to transfer the time-dependent outlet flow field to the inlet boundary.

My main questions are:

1. How can I extract the transient outlet flow field (velocity/pressure vs. time) from the first simulation?

2. Is there a recommended way to import this time-varying data into Fluent and apply it as the inlet condition?

3. Should this be done using a profile file, or is a UDF (DEFINE_PROFILE) required?

4. Is there any built-in coupling approach within Fluent for this kind of setup?

Any advice, workflow examples, or documentation references would be highly appreciated.

Thank you very much!

[RG]

Hi, 

I am assuming both outlet and inlet are part of same simulation set up. Here, you can apply profile from outlet-1 to inlet-2. This can be done by creating report definition for required variable at outlet-1. Use same report definition to define boundari condition at inlet-1 through expression. 

If you want to export exact profile and apply it on other boundary then it can be done through scheme or UDF. 

You also can use system coupling which helps you to couple 2 fluid simulation. 

These are different way to user profile from one surface to other surface.