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-   -   low re k-e models/ ske with ewt (http://www.cfd-online.com/Forums/fluent/75122-low-re-k-e-models-ske-ewt.html)

gina April 16, 2010 14:08

low re k-e models/ ske with ewt
 
please as there a difference between the standard k-e models with Enhanced wall treatement and low k-e models!

thank you to answer me

heidar April 17, 2010 04:11

from heidar.
 
there is some diffrences between the two models.
your question is a thematic question.
low reynolds models are disigned for low reynolds and are better than common models in suphisticated situations.
plz clear your requisite.
thanks.

heidar April 17, 2010 04:16

enhanced wall treatment is a appropriate method for resolving the flow structure near th a wall.
in fluent for a model u can choise 3 type of wall treatment.
and in fluent existed 3 version of K-e midel i recommend you to apply RNG model for computing the flow structure and behaviore.
because its time consumption is a little more than STD k-e but it is better for flow prediction.

now:

ok we r u from?

gina April 18, 2010 13:24

Quote:

Originally Posted by heidar (Post 255041)
there is some diffrences between the two models.
your question is a thematic question.
low reynolds models are disigned for low reynolds and are better than common models in suphisticated situations.
plz clear your requisite.
thanks.

thank you for your answer heidar,
for the study of turbulent flow in fluent and near the wall, I use the standard ke model with enhanced wall treatment. I want to compare with Low Reynolds ke model, but with this model there is no treatment associate near the wall !? why? can this model solves the flow near the wall!? and this model must to requir specific number of cells near the wall?

thanks

heidar April 19, 2010 00:32

heidar
 
hi gina
what is youre low reynolds model?
if you choose K-e turbulence models there is three wall treatmens that could be associate by the model to resolve the near wall flow structure.

if your choice is K-w the fluent automatically choose wolf stein one equation model as its wall treatment affair.
the automatic choosed wall treatment in SST and STD k-w models is equal by Enhanced wall treatment in wall treat for K-e models.

zero killed don't be woryy

gina April 19, 2010 09:46

Quote:

Originally Posted by heidar (Post 255168)
hi gina
what is youre low reynolds model?
if you choose K-e turbulence models there is three wall treatmens that could be associate by the model to resolve the near wall flow structure.

if your choice is K-w the fluent automatically choose wolf stein one equation model as its wall treatment affair.
the automatic choosed wall treatment in SST and STD k-w models is equal by Enhanced wall treatment in wall treat for K-e models.

zero killed don't be woryy

Hi Heidar,

I will to use Abe-Kondoh-Nagano model for low reynolds ke, because i will to study heat transfer...
you have not answer for my question please, why with low re ke model there is not near wall treatment?!

"there will be a dead and Fluent will be the killer ... the dead will be me:mad:"

heidar April 20, 2010 09:09

heidar
 
dear gina

what is your fluent's version?

gina April 20, 2010 15:50

Quote:

Originally Posted by heidar (Post 255449)
dear gina

what is your fluent's version?


hi, heidar,
i use FLUENT 6.3...
for my question about near wall treatment with low Re model, i found that this model dont need a treatment because he compute the entire boundary layer including the viscous sub-layer ;)

heidar April 21, 2010 06:53

heidar
 
be successfull

gina May 21, 2010 09:48

ke model with EWT and low re model
 
please I want to know, what is the diference between solving a flow with the standard ke model and enhanced wall treatement and resolving the flow with low Reynolds model?????????

heidar February 15, 2012 16:36

some differences
 
1- standard k-w uses wall function and your low reynolds number solve a two equation model, hence, low reynolds solution is more relieble
2- low reynolds is more time consuming because you should make the mesh dense every where
3- LRM is a modern model


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