Learning Forum

[Sofen Kumar Jena]

The original Launder Sharma Low Reynolds number Turbulence model is 

However the , the paper "https://www.sciencedirect.com/science/article/pii/S0045793013000820" mentioned that the implementation of the Low-Reynolds Launder-Sharma model in Ansys Fluent is not correct. 

Unfortunately neither Fluent theory guide or knowledge database has any documentation regarding the formulation of Low Re launder Sharma model in Fluent.

Despite of Low Reynolds number K-Omega model this LS model is good for many class of turbulent flow.

Documentation regarding the implementation of  Low-Reynolds Launder-Sharma model in Fluent will be useful. 

Cheers!

 

[Rob]

It looks like even the model index has been removed from the solver, so staff are unable comment on your question. I'm fairly sure they're for the k-e models though, Fluent didn't have k-w when they were in the manual(s). 

[Sofen Kumar Jena]

Then these Low-Re options are doing any random stuff in the computations ? Or any particular stuffs of equations are solved ? These options are still available in Fluent 2023. 

launder Sharma is a very popular model but non existance of any valid documentation in Fluent database is quite surprised. 

can I have the access to the old documents, even 20 or 30 years back ?

 

Sofen 

[Sofen Kumar Jena]

As an alternative approach, can you provide a minimal working example for disabling the wall functions for standard K-epsilon model. In the stanard K-Epsilon model one can alter the damping terms to redefine the Low-reynolds number K -Epsilon model when wall functions are off. 

 

Cheers.

Sofen 

[Rob]

That's a different model - clicking on Help ought to show up the documentation. The Launder-Sharma option (and a few others) is TUI only, and wasn't added to the GUI. 

I'm checking on what can be shared, but I suspect the best I can do is add it to the Portal side of things. I have a copy, but only because I've been here long enough to have to had support the option when it was "new": it's also marked internal only so can't share that version. 

[Sofen Kumar Jena]

No it is not different Model It is Launder Sharma K Epsilon Model. In GUI there is no option available, so I activated it from TUI and opted for the model index 2.

Some old Fluent manual available in google search has information, that the index 2 is for launder Sharma model .

Cheers 

 

[Rob]

And the second post, I can only refer you to the Help system and other public materials. 

[Sofen Kumar Jena]

Sure, 

Please provide some information that is helpful.

Cheers 

[Rob]

There isn't any additional documentation, and the models are unsupported - use with caution. 

[Sofen Kumar Jena]

(models are unsupported - use with caution) Flabbergasted !!!!

Even SIMPLE algorithem and upwinding scheme are more older than these models and Ansys has documentation for the same. 

If it is unsupported, please provide some alternative method to work with the same. For single phase one can use UDS to implement the same but in multiphase flow implementing Tchen-theory correlations is not going to easy. 

If models are still available in Fluent solver, then please provide some minimum working envronment to the user to access the same and modify the same. 

Cheers 

 

 

[Rob]

There is no documentation available, and these models are not supported.