More info:

For the first reference paper:

The case I am trying to reproduce is: particle diameter = 270microns, particle volume fraction = 0.1.

The paper was using CFX and I am using Fluent.

The settings I am using are consistent with the settings mentioned in the paper. The settings that the paper did not mention and I think they might influence my simulation results are listed below.

In addition, there is a difference between their geometry and mine. In their paper, L=44D, and cell no. = 801,848. Since I am using the student free version and I have the limit of 512,000 cell number. So in my case, L=25D and my cell no. = 508,600. My mesh might be different from theirs but I think my mesh resolution should be fine compared with theirs. Please see the attached screenshot of my mesh.

My Scaled Residuals plot is also attached.

Your valuable comments would be very very appreciated!!

Settings were not mentioned in the paper:

1. Materials - Fluid - solid: what is the viscosity value? (1e-6 kg/(m.s))

2. Multiphase Model - Phases - Secondary Phase - Granular Conductivity: syamlal-obrien

3. Multiphase Model - Phases - Secondary Phase - Frictional Viscosity: shaeffer

4. Multiphase Model - Phases - Secondary Phase - Frictional Pressure: Johnson-et-al

5. Multiphase Model - Phases - Secondary Phase - Radial Distribution: lun-et-al

6. Multiphase Model - Phase Interaction - Forces - Drag Coefficient: gidaspow

7. Viscous Model - Turbulence Multiphase Model: Per Phase

8. Velocity Inlet - Turbulence - Turbulent Intensity: 3

    Velocity Inlet - Turbulence - Hydraulic Diameter: 0.0072

    Velocity Inlet - Granular Temperature: 0.007272

9. Pressure Outlet - Backflow Turbulent Intensity: 0

    Pressure Outlet - Backflow Turbulent Viscosity Ratio: 0

    Pressure Outlet - Backflow Granular Temperature: 0

    Pressure Outlet - Backflow Volume Fraction: 0

10: Wall - Granular Conditions: Johnson-Jackson

      Wall - Granular Properties - Restitution Coefficient: 0.2