[michaelhoo]

I am now starting to correct the turbulence model in CFX. I have never done similar work before. I didn't find relevant information on the Internet. I don't know how to input formulas. Can anyone tell me how to get started next?Or provide some references or data.Thanks for all.

[Ashkan Kashani]

What are you trying to achieve by modifying a turbulence model in CFX? If you intend to tune an existing eddy-viscosity model, an alternative effective approach offered by ANSYS is the GeKo model, which provides you with much flexibility to fine-tune your model without violating the model calibration for basic flows. The GeKo model can be adjusted through a number of free coefficients, each having a predictable impact on the overall behavior.

[ghorrocks]

Can you explain what model you are trying to implement or what you are trying to change?

The references for everything you will want to do is in the CFX documentation.

[michaelhoo]

Under the low flow rate operating conditions of turbine, the flow field prediction is poor. I want to correct the turbulent kinetic energy generation term PK of the SST turbulence model. The CFX used version is 19.0 so Geko is not ok for me now.

[michaelhoo]

[IMG]‪C:\Users\58430\Downloads\0430.png[/IMG]

How to input the fomula into CEL?

[ghorrocks]

Your image was not attached. This FAQ describes how to attach images: https://www.cfd-online.com/Wiki/Ansy...n_the_forum.3F

It is highly unlikely that your "correction" to the equation will work without unintended consequences. Turbulence models are complicated things and unless you are a turbulence modelling expert I would not recommend trying to change them.

A better approach, if a certain region has too much production and therefore too much turbulence, is simply to use a source term to take a bit of the turbulent energy away. This does not involve adjusting anything on the turbulence models, can be properly linearised so it converges, and based on what you describe would achieve what you want.