Lagrangian particle tracking in mechanically agitated mono-dispersed and poly-dispers
 

Hi
I am working on Lagrangian particle tracking in mechanically agitated mono-dispersed and poly-dispersed suspensions.

1) Mono-dispersed suspensions
Details of my simulations are as follows:

-Continuous fluid: Water (volume fraction: 0.896, density: 1150kg/L)
-Dispersed Solid: Glass beads (volume fraction glass: 0.104; density: 2485kg/L; glass bead sizes: 1mm

Approach:
Step 1: I solve the flow field using the steady-state Eulerian approach.
Step 2: To perform the transient Lagrangian approach, I use the simulation results if the steady-state Eulerian approach as initial conditions. I inject the 1000 lagrangian particles of size 400 micron and density of 1150 kg/L (same as water) to track flow field of a continuous fluid and the 1000 lagrangian particles of size 400 micron and density of 2485 kg/L (same as glass) to track flow field of dispersed phase.

I have validated the results (for example velocity and solid distribution) of my simulations using experimental data (PEPT data), they are perfectly matched with experimental results.

So my question here are
Q 1: Is this right?
Q 2: when I inject the lagrangian particle in step 2 (Lagrangian approach), what should be the particle size and how do these particles knows that what they are tracking (continuous or dispersed flow field)? Because in case of Poly-dispersed suspension (see simulation details below) it is very difficult to decide the lagrangian particle size (that can track the solid flow field of 5 different glass)

Q3: Should the same of lagrangian particles same as dispersed phase size?

2) Poly-dispersed suspensions
Details of my simulations are as follows:

-Continuous fluid: Water (volume fraction: 0.896, density: 1150kg/L)
-Poly-dispersed Solid: Glass beads (total volume fraction glass: 0.104; density: 2485kg/L; glass bead sizes: 1mm, 1.5mm, 2mm, 2.5mm, 3mm, equal valume fraction i.e 0.2 X total volume fraction glass)
Approach:
Step 1: I solve the flow field using the steady-state Eulerian approach.
Step 2: To perform the transient Lagrangian approach, I use the simulation results if the steady-state Eulerian approach as initial conditions. I inject the 1000 Lagrangian particles of size 400 micron and density of 1150 kg/L (same as water) to track flow field of a continuous fluid.

How should I track the solid phase of 5 different glass?


If you know the answer or have any comment, suggestion are welcome.

Thank you
Regards
AJ