Hi!

I need to model a problem involoving non-newtonian fluid, but I can't find where do I have to put the viscosity data in fluent. The manual says that different models (non-newtonian Power law, carreau model, cross model and herschel-bulkley model) for non-newtonian fluids can be found in Materials-viscosity drop down list, but they are not there.

Help is greatelly appriciated.

mateus

Just start FLUENT, go to the Materials panel. If you click on the drop down list for viscosity expression, you can see the models you're looking for.

Hi

ap

Hi Ap!

Thanks for the fast responce. Strange thing. If you first define the materials (non-newtonian) and then read msh file it works. If you read a case file and then try to change the material properties to non-newtonian, the models are not there...

Thanks again!

MATEUS

FLUENT misteries

Good work

ap

non-newtonian models are only avalaibles in laminar. If in your case file a turbulent model is selected, non-newtonian models will not be avalaible.

If you want to use non-newtonian fluid with turbulence, you need to activate this option through command line in the fluent interface.

Hi!

You're right! Figure this...you have to write... define/models/viscous/turbulence-expert/turb-non-newtonian? and then select yes. I don't get it why this kind of stuff isn't mentioned in manual.

Does enyone have some expirience with non-newtonian fluids (nnf). I have a free surface problem with nnf. I have to simulate a mixing prosess (only mixer in one fluid). I have a lot of expirience with VoF bun non with nnf. The simulation works fine if i use water, bud deverges with nnf. What turbulence model should be used here. If I work laminar it converges.

thanks for your help

MATEUS