Simulation CFD - Defining Plastic Viscosity

Problem

Solution

When you are looking at a plastic flow simulation you can model the viscosity variation with any of the following variation methods: 2^nd order polymer, 1^st order polymer, and Power Law. 

2^nd order polymer: This is the most elaborate and encompassing variation method available in Simulation CFD.  Use of this model does require some data processing in Excel.  There is an excel sheet attached to this article that you can use to calculate the 6 coefficients that define the 2^nd order polymer material definition.

1^st order polymer: This model will take in to account Shear and Temperature effects. Use of this model does require some data processing in excel. There is an excel sheet attached to this article that you can use to calculate the 3 coefficients that define the 1st order polymer material definition. To use this spreadsheet you will need to leverage the SOLVER function in Excel.

 

After you apply the material to your volumes in Simulation CFD, make sure that you change the material environment settings to be variable instead of fixed.

Some common questions:

Is there a difference between Shear Rate and Strain Rate?
Not for this software.

Should I model the plastic flow with the laminar or turbulence solver?
Running with the laminar solver is suggested.

Can the software solve for viscous heating?
Yes.