For two-fluid euler-Euler model with Granular kinetic model, when defining a new solid as secondary fluid phase, we need to input a density which we always know. In addition, the value of the viscosity is also needed.

Now my question is that:

(1)how to define the viscosity value? If thisvalue is not correctly given, what will be the effect on the simulation result? Important ot negible?

(2)As we know, in Granular kinetic model, there is a set methodology to calculate the solid granular viscosity. Then what is the difference between the two kind of viscosity mentioned above?

Does someone have any idea for this?

The viscosity defined in the materials panel is not of much importance, as the granular viscosity will be used in the calculations when you turn on the granular option...

- Sujith S Nair

I have a similar problem, and i do have to use the granular option. Any help would be appreciated by these questions.

In multiphase with secondary phase as solid, Fluent solves the governing equations formulated using granular kinetic theory. The behavior of solid particles is almost similar to that of fluid. The granular viscosity in solids is the analog of molecular viscosity in the case of fluid.

The viscosity of the granular secondary phase is the granular viscosity. The viscosity of secondary phase material does not have any major role in this formulations.