Laminar Solid-Liquid (Two-phase flows) flows in CFX
 

I am using CFX v12.1 to solve two-phase flows in a horizontal pipe. Both the continuous (liquid: density = 867 kg/m3) and dispersed (solid: sand with density 2650 kg/m3 and d32=0.43mm) are model as laminar.

Convergence is not my problem, however, the volume fraction (VF) results doesn't agreed with the published experimental data. The experimental data indicates that the sand settled and almost stratified flow. The delivered concentration was less 50% of the inlet VF. CFX indicates that there is an effective transport of the sand with almost 100% delivered concentration.

Since the VF or concentration profile is "wrong", I don't trust the velocity profile it is giving me, despite the pressure gradient is somehow closed to the experimental data.

I am not sure if it's coming from liquid-solid interaction model (kinetic theory), since it's is based on turbulent flows. should turbulent or laminar really matter for this model?

Any help on this will be much appreciated. Thanks.