Hello, I use fluent and need to simulate polymer viscosity vs shear rate and the turbulence. I've try with some turbulent models but they want constant viscosity to calculate the turbulence.

Is it possible to copy the non newtonian model in a UDF and then use a turbulent model. I've never try to use UDF until now.

Thank you for advice

David

To use turbulence with non-newtonian fluid, you need to activate the turbulence model through the command line not through the GUI.

So to resume, you doesns't need to use UDF for your problem.

I wrote

define/models/viscous/turbulence-expert/turb-non-newtonian?

but the command is not valide. I received this message "invalid command".

Thanks

What version of Fluent do you have? in 6.0.12 the command is not available.

The version is Fluent 6.2.16.

Is it possible to check if I have all the libraries to use the turbulence with the viscosity of non newtonian fluids.

Hi David, First select the standard k-e model, then use TUI and write define\model\viscous\turbulent expert\ Then you can select

turb-non-newtonian? Enable turbulence for Non-Newtonian fluids.

non-newtonian-modification? Enable Non-Newtonian modification for Lam-Bremhorst model.

Hope that can help - Wael

Thank you a lot.

I use it with non newtonian power law.

I wanted to define viscosity by this function:

v=v0*exp(b(T-T0))*g^n where : v=viscosity b=constant T=temperatur g=shear rate

thanks for you kind help

[arne711]

Hello,
I am looking for some information about the implementation of the Ostwald de Waele Power Law into Ansys Fluent or OpenFOAM for a research project.
So if anyone could recommend an interesting paper or would even be able to share some code I would be really happy.
I would be especially interested in the modified momentum continuity equation. As far as I understand it's not hard to substitute the power law for the shear stress but I didn't find any information about solving it in a three dimensional geometry.

Thank you!

[KOTTE SHIVA YADAV]

hello @arne711



I am also stuck with same problem can you please help me in implementing Power law model in OpenFoam?


Thanks in Advance