Optimal Settings for two phase(Solid Liquid) granular eularain multiphase flow
 

Hey there! I'm currently working on a two phase solid-Liquid flow in a cylinderical annular geometry. My fluid is drilling fluid which is colloidal in nature(4% sand concentration). I'm seeking advice on what should be the optimal physics or what things should i be cautious for such transient turbulent non newtonian flow.

I'm currently using k-epsilon turbulence model with a velocity inlet and pressure outlet with second order upwind for turbulence and momentum. i have tweaked under relaxation factors for pressure, momentum and tubulent viscosity to 0.5, 0.2, 0.8 respectively as suggested by ANSYS documentation. I have used Symlal-obrien for granular viscosity and Gidaspow model for drag. Rest all setting are default.

Also, I'm having a hard time finding publications for validation as most of the papers don't give openly tell what physics they have used for their validation. If someone happens to have knowledge of such publication for sand- water validation, kindly share that too if it isn't too much trouble.

How did you define concentration of sand in water?