Using a journal file to apply periodic boundary conditions
 

I am working on a periodic fluid flow and heat transfer problem in a pipe.For the fluid flow part I will have to write the velocity profiles at pipe outlet and read them at the inlet for each period till the flow is fully developed and for the heat transfer part I will have to write the outlet temperature at the end of each period, re-scale the profiles using a matlab code and read them at the inlet till thermally fully developed condition is reached. I am not familiar with journal scripts in fluent so please suggest a way to automate the process using TUI feature of fluent or by using a journal file.

Fluent already has a periodic B.C., so you don't need to do it "by hand". Is there a particular reason for doing so?

In case you still want to do it (maybe you want to test a specific scaling for the temperature), you can check this:

http://www.cfd-online.com/Forums/blo...nt-part-4.html

It is an UDF for mapping the velocity fields (adding the temperature is trivial) from one generic face to an inlet one during the simulation. In your case you should just set the two faces as the inlet and outlet of your domain and follow the instructions in the UDF.

Still, if just periodicity is what you want, then use the default one already implemented.

I have tried the periodic condition in fluent but had issues with convergence for my pipe geometry so I am planning to do it this way. Thanks for the inputs.