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NickolasPl August 12, 2011 07:23

Power - Law Viscosity Model for Polymers
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!

elvis August 12, 2011 08:19


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

NickolasPl August 12, 2011 08:26

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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