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Manu September 14, 2006 12:52

SAS Model
 
Hi Robin Do you know what is SAS Model?Can it be used for predicting Transitional flows??I checked in CFX 10.0 but its not there in the list of turbulence model.

Please write something about it.

Thanks in advance

Manu

luis September 14, 2006 16:55

Re: SAS Model
 
Try this http://www.ils.uni-stuttgart.de/aktu...turbulence.pdf http://www.flm.mw.tum.de/ERCOFTAC/pd...005/Menter.pdf http://www.tfd.chalmers.se/~lada/pos...comas_2006.pdf


Manu September 15, 2006 04:27

Re: SAS Model
 
Hi Louis , Thanks for the information provided.Can you please write something about how to use this model in CFX 10.0??

Regards

Manu

zxaar September 15, 2006 06:11

Re: SAS Model
 
this is not available in 10.0 version, but it in 11beta version, contact your cfx support.

longbow September 15, 2006 08:10

Re: SAS Model
 
It is actually a Beta feature in CFX-10. However, you can not access it through GUI. You have to do it with ccl. There is a technical tip talking about how to use it on old CFX community website. Hopefully, you can find it in its new location. By the way, SAS model will not predict transition.

Manu September 15, 2006 11:11

Re: SAS Model
 
Hi longbow

Did you try SAS for predicting transition in the range of Re 1300-2000.What waas the outcome. CFX spport says it is modeled for the same.Please through some light on it.

Thanks in advance

Manu


longbow September 15, 2006 13:20

Re: SAS Model
 
For me, SAS is just another turbulence model, like SST, LES, DES, etc. That's why I say it can not predict transition from laminar to turbulent flow. To answer your question, I haven't modeled transition for low Re flow. I did use transition model in CFX to model axial fan with high Re. Since the flow in the area I am interesting in is already turbulent, transition model doesn't help a lot. Back to your case, maybe your flow is just laminar. That's why with and without transition model is the same.

Robin September 15, 2006 13:37

Re: SAS Model
 
There is an SST-SAS model in development which includes the transition model, but it is not available in version 10.0.

-Robin

zxaar September 15, 2006 17:59

Re: SAS Model
 
yes, this is what I meant by saying that it is in version 11 beta. And yes, SAS does not help in predicting transition, it only adds a source term to W equation of SST model (for which you can enable transition), this is their SAS-SST transition model.


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