|October 9, 2014, 01:15||
NonNewtonian Modeling Coefficients
Join Date: Jun 2012
Posts: 55Rep Power: 5
I am modeling the flow of grease over a body. I know that grease is a "shear-thinning" fluid so I am trying to apply the Bird Carreau Non-Newtonian model. You can see the equation describing the model here:
However, I am confused about the parameters for the time constant and power-law index. I was reading that you have to do a curve fit to get these? Any advice on how to do this would be appreciated.
I currently have the viscosity at high and low shear viscosity. I also have some values of the shear rate and corresponding viscosity at different temperatures. However, I am not sure how to graph these to get the time constant and power-law index.
|October 9, 2014, 05:50||
Join Date: Mar 2009
Location: Sydney, Australia
Posts: 11,567Rep Power: 90
If solving the equation for TC and index is too hard, then guess a TC and index and see what viscosity it gives you. Then adjust your TC and index guesses until it gives you the right viscosity.
You can do this in Excel using "goal seek"... or any other numerical program (python, matlab, etc)
|Thread||Thread Starter||Forum||Replies||Last Post|
|Modeling NonNewtonian fluid in an annulus using "nonNewtonianIcoFoam" solver||Aelsawis||OpenFOAM||0||March 16, 2010 08:10|
|Nonnewtonian fluid modeling||adam||FLUENT||0||June 16, 2006 05:23|
|May Focus Area: Turbulence Modeling||Jonas Larsson||CFD-Wiki||0||May 2, 2006 11:48|
|Modeling Flow/Saturation/Absorption in Fibers||Gene Dougherty||Main CFD Forum||0||June 6, 2003 14:49|
|CFD Modeling of Two-phase Flow in Small Dia.Tubes||Eric Poindexter||Main CFD Forum||2||September 22, 2000 09:21|