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Power - Law Viscosity Model for Polymers

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Old   August 12, 2011, 07:23
Default Power - Law Viscosity Model for Polymers
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Nickolas P
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Hello everybody,

I'm working on a project for my Master Thesis and I m studying polymer rheology and polymer melt flow under certain geometries. I have benchmarked some very rough and primitive cases for polymer flows using power - law viscosity model and the results are very good. However, in polymer melts, the viscosity is strongly affected by the temperature and this is expressed as:

eta = eta0*exp[-b(T-Tref.)]

etao is the reference viscosity at the reference temperature Tref. b variable, is a value that shows how much the viscosity is affected by temperature and actually b values are tabulated and in many softwares this is an input value.
So my question is if this value is included in the power law viscosity model? I understand all tha input data in TransportProperties dictionary but I dont see anyware any input value for b. Can anyone help me out?is there a possibility to change the viscosity model so that the viscosity is affected by temperature through the b value?

Thanks in advance!
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Old   August 12, 2011, 08:19
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Elvis
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Hi,

I just wanted to point out that there are many viscosity laws implemented by Jovani Favero.
These laws are only available on Of1.5-dev or Of1.6-extend not on OpenCFD version of Openfoam

Viscoelastic Fluid Flows using OpenFOAM The solver viscoelasticFluidFoam
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Old   August 12, 2011, 08:26
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thanx for your comment Elvis. I have seen this thread sometime ago but it covers a different subject of polymer rheology. However, I m gonna make a post there also. Thanx!
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