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Angmar September 29, 2010 10:33

how modify standard turbulence model
 
Hello.
Please, tell me how I can modify standard k-e turbulence model?
I need to take into account an influence of compressibility corrections on the intensity of turbulent mixing.
For example I need compute turbulence viscosity on a new equation.

Or tell me where I can take such turbulence model (like k-e Chen) and how to connect it to my CFX 12.1?

P.S. sorry for my English.

Attesz September 29, 2010 10:54

Hi,
you can modify the contants and other parameters in CFX-pre, in the advanced settings (or something like that). But modifying the constants can cause incorrect results.

Angmar September 29, 2010 12:28

I've tried already. coefficients in turbulence model mast be constant 8(
I know that in CFX I can write a special program module, but don't know how to do it

ghorrocks September 29, 2010 18:47

Have you tried SST? That may be more accurate for what you are trying to do.

If you are thinking of doing your own turbulence model then I assume you are a turbulence expert - this is not something for beginners.

You can implement general turbulence models through the use of additional variables and CEL functions behind it. For many models you won't need fortran. Obviously the convergence and stability problems this generates is your problems to sort out.

ghorrocks September 29, 2010 18:48

Oh yes, and possibly CFX V13 allows you to set some turbulence parameters as dynamic CEL expressions. Talk to CFX support about whether this is true or not, and whether it will allow you to control the variables you need.


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