[Payamsz]

Hello
I want to simulate solid liquid flow inside annulus.
Geometry:
Di=2 in
Do=4 in
L=60 in
Particle size= 3mm
Model:
Steady state
Eulerian eulerian grannular flow
K ebsilon turbulence
BC:
Inlet velocity
Outlet pressure
Moving inner pipe 80 rpm
Stationary outside wall
________________
ROP (rate of penetration in drilling) = .01 m/s
Q_particle= ROP * A_annulus
_________________
The single-phase flow is easily solved.
When i choose two phase eulerian model i dont know how to calculate volume fraction of solid particles.
For example i put volume fraction of solid 0.3 and and velocity inlet for solids 0.01 m/s .
Solution didnt converged.
Please help me