Learning Forum

[Masi]

Hello,

I am working on drug delivery. We have more than one million droplets in micrometre ranges. I want to use the two-way CFD- Rocky coupled model for simulating the transport and deposition of these particles in the mouth-throat. Particles that come into contact with the wall should be trapped. How can I consider this boundary condition in Rocky? And how can I get the result of the amount of particles deposited on the wall?

 

[Rob]

You'd need to look at the wall adhesion models. Is there a reason for using Rocky over Fluent? I'd favour Rocky for systems where particles are present at high volume fractions and collisions are significant. For an inhaler I'd typically be looking at Fluent's DPM model unless there's something new in the drug delivery mechanism that I'm missing?

[Masi]

Thank you for your reply. 

We can utilize Fluent to generate a DPM file on walls to analyze particle behavior. I'm curious about how we can achieve similar results using Rocky.

Inhaler plumes, specifically near the nozzle, particles have a high volume fraction; also, due to the nature of flow inside the pipe, collision becomes important, which, for simplification, particle-particle interaction is ignored in most cases. I want to consider this phenomenon in my model, as I'm new to Rocky; I'm wondering if it's applicable to my model.

 

 

[Rob]

It could work, but you're then relying on the code interaction for the fluid flow field. It can work, but I'm not sure it's necessary. Have a look at the collision model in Fluent's DPM. But with non-sticky particles do you expect collision energy to be high? 

[Masi]

Actually, particles are sticky, and adhesion is the predominant factor. The primary aim is to compare the modelling of the transport of these particles between DPM and Rocky.

[Rob]

In which case look at particle adhesion. Wall adhesion is a separate effect. Then look at the reporting to figure out what went where - most of that is covered in the tutorial (someone asked recently on here).