Whenever a problem in ComSol is not already implemented, you can always use equation based modeling. Also, using definitions in the definition node, you can have the physical properties of blood (such as viscosity) depend on other parameters or variables, whilst still using for instance a laminar flow module (where you write down the definition of the viscosity instead of just a constant value).

All the best

I also believe that the problem may be handled by COMSOL Multi-physics.

These are my suggestions:

First understand how COMSOL Multi-physics works. Get right the equations to be used and the operation procedure for the solution.

You may re-derive the non-Newtonian power-law equation to include rotation (or rotational Reynolds’ number) and take into account the range where flow behavior index, n for blood falls. When n=1, it is Newtonian equation and this may serve as the basis for the correctness of your PDE equation.

Note the scope of validity of Carreau model. The knowledge of the scope of Carreau model may enable you determine your assumptions.

You may need to know the input data that defines the shape of the geometry of interest and the physical properties of the fluid such as density, viscosity and parameter like flow behavior index, n, etc.

You should define an analytical function in Materials section and use this function as your viscosity. The input of this function should be Spf.sr (shear rate). (If your models is not Laminar flow the "Spf" part changes)

hello,  I want to model blood flow as you,could you help me please.