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-   -   Only two turbulence options available in CFX Pre (https://www.cfd-online.com/Forums/cfx/168797-only-two-turbulence-options-available-cfx-pre.html)

Jack001 March 29, 2016 09:20

Only two turbulence options available in CFX Pre
 
Hello,

I am running CFX v16.0 and I wish to run a transient simulation using DDES/SAS/LES models. I am setting my case up with the help of CFX pre Turbo Mode. However when I select the transient option in the wizard, the only Turbulence options I have to choose from are k-epsilon and Shear Stress Transport options. Looking at the guide for CFX pre there should be a range of options available:

Code:

12.4.2.3.2. Turbulence: Option

You can select one of the following turbulence models:

None (Laminar): Turbulence is not modeled. This should only be used for laminar flow. Of the combustion models, only Finite Rate Chemistry is available for laminar flow. For details, see The Laminar Model in the CFX-Solver Modeling Guide.

k-Epsilon: A standard fluid model that is suitable for a wide range of simulations. For details, see The k-epsilon Model in the CFX-Solver Modeling Guide.

Fluid Dependent: Allows you to set different turbulence models for each fluid in the domain. If this option is selected, the turbulence model for each fluid is set in the Fluid Specific Models tab. This is only available for multiphase simulations when Homogeneous Model is not selected.

Shear Stress Transport: Recommended for accurate boundary layer simulations. For details, see The k-omega and SST Models in the CFX-Solver Modeling Guide.

Omega Reynolds Stress / BSL Reynolds Stress: For details, see Omega-Based Reynolds Stress Models in the CFX-Solver Modeling Guide.

QI / SSG / LRR Reynolds Stress: Provides high accuracy for some complex flows. For details, see Reynolds Stress Turbulence Models in the CFX-Solver Theory Guide.

Zero Equation: Only the Finite Rate Chemistry combustion model is available when using the zero equation turbulence model. For details, see The Zero Equation Model in the CFX-Solver Modeling Guide.

RNG k-Epsilon: A variation of the k-epsilon model.

k-Omega / BSL: The SST model is often preferred to this model.

k epsilon EARSM / BSL EARSM: These models are a simplified version of the Reynolds stress models with application to problems with secondary flows as well as flows with streamline curvature and/or system rotation. For details, see Explicit Algebraic Reynolds Stress Model in the CFX-Solver Theory Guide

LES Smagorinsky / LES WALE / LES Dynamic Model: Available for transient simulation only. For details, see The Large Eddy Simulation Model (LES) in the CFX-Solver Modeling Guide.

Detached Eddy Simulation: Available for transient simulation only. For details, see The Detached Eddy Simulation Model (DES) in the CFX-Solver Modeling Guide.

SAS SST: Available for transient simulation only. For details see, The Scale-Adaptive Simulation (SAS) in the CFX-Solver Modeling Guide.

Eddy Viscosity Transport Equation: A one-equation variation of the k-epsilon model. For details, see The Eddy Viscosity Transport Model in the CFX-Solver Theory Guide.

Any ideas how to enable these models?

Opaque March 29, 2016 11:49

Finish your setup in the Turbo mode, and the switch to the General Mode where you can customize nearly anything that the Turbo mode wizard hides.

Hope the above helps,

Jack001 March 29, 2016 12:05

Thanks for the response! How do I actually get into the general mode you describe?
http://postimg.org/image/f1z3zsvoj/

Opaque March 29, 2016 12:06

The software will ask you once you are at the end of the wizard.

Jack001 March 29, 2016 12:13

Ah yes sorry I was being stupid. So the general mode is the view with list of tabs on the left of the GUI? I was searching around that too but couldnt find any tab to set the model. I can choose the main tabs labelled

MESH
SIMULATION
SIMULATION CONTROL
CASE OPTIONS

is it within any of these, because I cant find it. Sorry if im missing something obvious!


EDIT:

I found the tab eventually by clicking on the main domain tab under SIMULATION -> FLOW ANALYSIS 1 but it does not contain LES smagorinsky or SAS and DES options although it does cotain SSG Reynolds Stress option. Any ideas where the rest are hiding?

EDIT2:

I found them you have to import the others by clicking on the "..." tab next to the drop down menu.

These things make me feels so stupid... But thanks for pointing me in the right direction!

-Maxim- March 30, 2016 02:47

Quote:

Originally Posted by Jack001 (Post 592208)
I found them you have to import the others by clicking on the "..." tab next to the drop down menu.

hehe you just learned a very important lesson for using CFX: that "..." usually hides the stuff you need (like extra variables and options) :)


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