Implementing sub-grid viscosity

Submitted by carl on Fri, 01/14/2022 - 17:09


The fluid viscosity in a suspension depends on the voidfraction, (eg. the Einstein Equation) or the Batchelor-Green viscosity:

In the article of by B. Blais et al (2016), they modify the smagorinsky turbulence model to create a sub-grid voidfraction:

My aim is to implement the Batchelor-Green viscosity this way instead of changing the cfdemSolverPiso. Eventhough I changed the Smagorinsky model and inserted the Batchelor Green equations and added needed utilities, and the simulation run, the result is many magnitudes too small.
Have anyone tried to do something similiar or willing to take a look at my code to see if there is something I missed?
If not I would appreciate the help of someone who has changed the viscosity of the cfdemSolverPiso, with an example.