[fs.chemech]

Hello friends,

Hope everything is ok.

I'm opening a new topic despite knowing that there are some other very similar. It happens that none clarifies me as I need...

So, I'm using solver simpleFoam to simulate blood in a 2D geometry as a newtonian and non-newtonian fluid and the only model that is giving me problems is power -law.

The power-law viscosity model has two parameters and, for blood, I found in the paper of Neofytou & Tsangaris (2006) the following values:

• k = 14.67×10−3 Pa.s^n
• n = 0.7755

I know that OpenFOAM uses kinematic viscosity and when I analysed the code of power-law model, noticed that the consistency index, k, as the same units of nu. So, I simply divided the value of k by rho (1040 kg/m3), and got a value of 1.411×10−5 m2/s for k.

In a first phase, I used this value in my simulation and it diverged rapidly.

In a second phase I have initialized all fields with potentialFoam and my simulation still doesn't converge.

I noticed, in some tutorials, that k has values in the order of 2500 and I have some questions:

1. Is anything escaping me? Am I supposed to obtain a value of k of this magnitude for blood with the data that I have available?
2. One thing I do not understand is the n exponent in the units of k. Can somebody explain me why is this exponent there? What does it mean?

I really need your help to proceed with my work. Sorry for my newbie question!

Cheers,

FS