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-   -   how to see the contour of intermittency? (https://www.cfd-online.com/Forums/cfx/88743-how-see-contour-intermittency.html)

mohammad May 25, 2011 00:24

how to see the contour of intermittency?
 
1 Attachment(s)
Hey;
i was reading the Ref[1]. somewhere in the paper, it presents the intermittency contour over the suction surface of a NREL blade.


I'm wondering how to plot this picture in CFX11?



Ref [1]-Predicting 2D Airfoil and 3D Wind Turbine Rotor Performance using a Transition Model for General CFD Codes. By:R.B. Langtry, J. Gola, and F.R. Menter

Josh May 30, 2011 23:57

Hi Mohammad -

Make a contour plot (if you don't know how to do this, do the tutorials).
Select "Turbulence Intermittency" as the plot variable.
Set your range of values from a minimum of 0 to a maximum of 1.

Good luck.

mohammad May 31, 2011 09:22

Quote:

Originally Posted by Josh (Post 309848)
Hi Mohammad -

Make a contour plot (if you don't know how to do this, do the tutorials).
Select "Turbulence Intermittency" as the plot variable.
Set your range of values from a minimum of 0 to a maximum of 1.

Good luck.

Hi Josh.
Thank you for your help. My problem is that i cannot find that option; I mean
" Turbulent Intermittency". I check it now again.....In my CFX 11 there exist no such an option.

am I right? could you please check it in your software?

TNX

Josh May 31, 2011 14:42

I'm using CFX v12.1. I don't think intermittency is a variable in CFX v11 since the gamma-Re_theta model isn't implemented in that version. What turbulence model are you using? If it doesn't use intermittency, you won't be able to plot it!

Remember, intermittency is an additional variable implemented either as a correlation, e.g., Dhawan and Narasimha (1958), or as a transport equation, e.g., Steelant and Dick (2001). It is not a general fluid/CFD variable, e.g., vorticity, that can just be calculated based on the flow parameters. Therefore, if your turbulence model doesn't use intermittency, it won't be available to plot.

mohammad May 31, 2011 20:39

1 Attachment(s)
Quote:

Originally Posted by Josh (Post 310011)
I'm using CFX v12.1. I don't think intermittency is a variable in CFX v11 since the gamma-Re_theta model isn't implemented in that version. .

Dear Josh....
As I read in Ansys FCX help texts Gamma-Re-theta exist in CFX11. ( See the attached picture please). If I'm wrong , tell me. And because in future others may read this post let's clarify it.
For more info please also read the following links:

http://www.cfd-online.com/Forums/cfx...-vs-cfx11.html
http://www.cfd-online.com/Forums/cfx...x12-cfx13.html

One other thing is that you are right about the option existence. I was looking for it in one of my results i had got by SST model not Gamma- Theta. I found it on on the correct file.

TNX and Good Luck


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