Dear cfx users,

I have difficulties implementing a cel file (which pi gave it to me)in cfx 5.6. I have read the chapter which is provided in manual but all the explanations are regarding the ccl and the expression editor. So which is the procedure of loading a cel file?

Thanks

ioana

Hi iona,

Please, try this; -give the expression file a name, say, "myiona.ccl"

-In pre import it as ccl with the 'Append' option toggled on.

Your statements should be between the these expressions:

LIBRARY :

CEL :

EXPRESSIONS :

===="IONAS statements here"=====

END

END

However, note that Anne is also struggling with CEL as you can see from her postings. So, just give this a try.

Anne

Hi Ioana,

I think you have your terminology mixed up. "CEL" is the expression language used by CFX5 so that it can evaluate user definable formulas and the like during a simulation. "CCL" is the setup file of a CFX5 run, and contains boundary condition information, which models to use etc etc, as well as any CEL expressions for the simulation.

I think you are actually trying to implement a CCL file. There is no such thing as a CEL file.

Glenn

Hello Anne and Glenn,

Thanks for your response. I am a little bit confused right now. So my problem is as following: I need to set the absorption coefficient, which is defined with an " if " structure. I tried to do this with the expression editor but I couldn't. Then I have asked the forum and pi was telling me to use CEL and he generate the file for me. Now as I really need it I have tried to load it. But how to save the file as a CEL file? I read in the manual and all the explanations are regarding the CCL and the expression editor. For CCL it says that you must know Fortran. I don't know so I am trying to avoid this. About CEL it says that you don't need Fortran. So is or is not a way to describe a "if" structure without using fortran?

Have a nice day,

Ioana

Hello Ioana,

Whould you mind sharing what you are trying to do with the Absorption Coefficient? Perhaps there are other alternatives for doing what you intend.

What radiation model are you planning to use?

Thanks Juan Carlos

Hello Juan Carlos,

Thanks for you reply. I am trying to simulate a fire in a room (Steckler room). When choosing from the library the reaction/new material that it will be use at the Override advanced properties the Absorption coeff was set to 0. I have changed it to 0.315 1/m. The radiation model used was Discrete transfer (however I still reach that point to really deal with it…). I found in a paper the following description for the absorption coefficient:

a = 0.01 if T< 323 K

a=0.01 +(3.49/377)(T-323) if 323<=T<700 K

a=3.5 +(3.5/700)(T-700) if T>700

and I want to implement it in my file. I have posted my question in the forum 1 month ago and pi answer me http://www.cfd-online.com/Forum/cfx.cgi?read=7522, however because something came up I postponed the abss coeff.

So, is there any way to do it, without Fortran?

Regards,

Ioana

Hello Ioana,

I have modified the file from Pi, to allow CFX-Pre to import it properly.

Here are the steps to get this going (I assume is new, skip as needed) :

1 - Start you simulation, New or Open an old one.

2 - From the File menu, select Import CCL (that is what Pi's file below is).

3 - Browse and select the file containing your CCL extract.

4 - Wait for loading, then click on the Expression Editor tabs. Your expressions should now be there.

5 - Go to the Materials tab, select/create your mixture and go the mixture properties section.

6 - For the Absorption Coefficient, press on the expression toggle (sqrt of Alpha), and type the name fo the Absorption Coefficient expression. For the file below: MyAbsorp

7 - Press OK, and you can continue with your setup

Hopefully that's all, Juan Carlos

LIBRARY:

EXPRESSIONS:

T1=323 [K]

T2=700[K]

f1=step((T-T1)/1 [K])

f2=step((T-T2)/1 [K])

a1 = 0.01 [m^-1]

a2=0.01 +(3.49 / 377.)(T-323[K]) [m^-1]

a3=3.5 +(3.5 / 700.)(T-700[K]) [m^-1]

A=a1+(a2-a1)*f1

MyAbsorp=A+(a3-A)*f2

END

END

END

COMMAND FILE:

Version = 5.6

END

Hi Juan Carlos,

Thank you very much for you comprehensive reply. It is very helpful, but I still have one question: how to make a CCL file? I know it seems strange, but I have the file in word, so I must convert it to CCL. How to do it?

Can you give me some advice in this direction too?

Have a nice day,

Ioana

Don't use word. Use Notepad (or an other ascii-editor such as Textpad) and save the file as filename.ccl

Kind regards Michael Bo, DK

Hi Ionna,

I think the easiest way to do what you want is to create the expressions in CFX-Pre, (go to Tools, Expression Editor). There are some examples about creating expressions on the tutorials, for example Tutorial 3, pages 122-124. To replace your if conditions, you may use step functions as already mentioned by somebody. If you want to know more about CEL (CFX Expression Language), take a look on the manual at Reference Material, CFX Expression Language. Alternatively search for CEL on the master index.

Rui

Dear Anne, Glenn, Juan Carlos, Michael Bu and Rui,

Thank you very much for your answers. I imported the CCL file and it works.I am very happy.

Have a nice day,

Ioana

Hi ioana,

There is no "if" structure in CEL expressions per se, that functionality is performed using the "step" statement. Have a look at the step function in the CEL documentation.

Glenn