# nonuniform temperature boundary condition

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 March 11, 2010, 14:34 nonuniform temperature boundary condition #1 Member   Join Date: Feb 2010 Posts: 33 Rep Power: 7 hello when i want to use a nonuniform temperature distribution at inlet as a boundary condition (values from measurement), what do i have to do? - where can i set this BC? - what kind of file does it has to be? - any other things i have to consider? i checked the user manual and the only thing i found is something about a junction box routine that i don't understand... how should i approuch to this problem? thank you very much!!!

 March 11, 2010, 15:36 #2 New Member   Join Date: Dec 2009 Posts: 13 Rep Power: 7 The first thing you'll want to do is create a user function. Specify whatever input/output units you want, and give it the data points for the function. If you like, you can create a variable (such as the radius in a cylindrical system calculated from cartesian coordinates) that can be used as the input. Once you have the function specified, open up the boundary conditions for your inlet. Under Heat Transfer, select the type of temperature you are inputting, and in the text box, put: NAMEOFFUNCTION.OUTPUTVARIABLE(INPUTVARIABLE) E.g. if your function was called InletT, with the input being "radius" and output being "Tt", you would put InletT.Tt(radius) That'll do it. You can also specify the function from a text file if you like (instead of putting the points in manually)

 March 12, 2010, 00:45 #3 Super Moderator   Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 10,830 Rep Power: 85 I might rewrite puga's first sentence as "The last thing you'll want to do is create a user function". Avoid user fortran if at all possible is my advice. The first thing you should try is using a simple 1D lookup table as a CEL expression. You can enter your data points as a temperature vs height dataset and use that as the temperature field for your inlet. See, easy and no fortran required. Only go to fortran if you can't do what you want in CEL - and 95% of the time it can be done in CEL.

 March 12, 2010, 07:42 #4 New Member   Join Date: Dec 2009 Posts: 13 Rep Power: 7 I wasn't implying user Fortran. You can simply scroll to the bottom of the main menu and click "add user function." No fortran required. I should also put the caveat that I'm using version 11.

 March 15, 2010, 16:47 #5 Member   Join Date: Feb 2010 Posts: 33 Rep Power: 7 CEL !!! was the answer thank you...

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