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-   -   User CEL or Junction Box routine? (http://www.cfd-online.com/Forums/cfx/20055-user-cel-junction-box-routine.html)

Lexi December 16, 2003 09:25

User CEL or Junction Box routine?
 
Hello!

I have tables with the pressure and temperature dependencies of my materials. Do I have to take user CEL or junction box routines to read the data?

Lexi

Neale December 17, 2003 01:26

Re: User CEL or Junction Box routine?
 
User CEL functions should work fine to define the properties (density=f(T,p) and Cp=f(T,p)). You will probably still need a junction box routine in the "User Input" location to read your table data though.

Neale.

Glenn Horrocks December 17, 2003 17:37

Re: User CEL or Junction Box routine?
 
Hi Lexi and Neale,

You can import your CEL tables into CFX-Pre, or you can copy/paste them into the CEL text file and write them into the definition file with the cfx5cmds command. You won't need a junction box routine to read it in.

Glenn

Neale December 18, 2003 01:15

Re: User CEL or Junction Box routine?
 
Yes, but you must use the cloud of points interpolation for two-dimesional functions (eg: rho(T,p)).

This is somewhat awkward because the cloud of points method requires 3D input data, so you must put zero in for the third column, and the data is unstructured so you must copy the ordinate values a bunch of times that is really unecessary.

Normally the cloud of points is for clouds of x,y,z values, that's why it's a bit awkward to use it for T,p tables.

However, as you say, it can be done without a junction box.

Neale

Bart Prast December 18, 2003 07:17

Re: User CEL or Junction Box routine?
 
I wouldn't recommend cloud of points for material properties as it used to be very slow (CFX improved it but I do not know to what extend). Better to write your own interpolation routine (structured for rectangular P,T domain) as you can put in all the acceleration in there.

Glenn Horrocks December 18, 2003 17:37

Re: User CEL or Junction Box routine?
 
Hi Neale,

Good point - now I understand the issue.

Glenn

S. Balasubramanyam January 22, 2004 09:52

Re: User CEL or Junction Box routine?
 
Hi, I have a relationship between temperature and liquid fraction. The relationship varies for different ranges of temperature. During runtime I need to update the liquid fraction by taking temperature as input. Following the examples in the manual I have written a small fortran code and created a dll. But I am getting an error, which says that it is unable to load the symbol. Also it says that the specified procedure could not be found. I am not able to understand this. Can anyone help me? Thanks in advance.....balu.


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