Particle Trapped on The Wall
 

Hello!

I am working with particles in a unique domain. But I need to know how many particles deposit on the wall in three different portions (like if I divided my domain in three).

So, in CFD post, I created cross-section planes and calculate the mass flow of the particles using the function calculators.

But I have a problem: in some portions recircuations zones exists, so the mass flow are bigger than the real number of particles.

Anybody could help me? Anyone have an idea to divided my domain in three parts and then calculated how many particles deposition in each parts?

Thanks in advance!

I forgot to say: I am using Eulerian-Lagrangian approach.

Hi,
If you assigned 3 boundaries (wall1, wall2,wall3) in CFX-pre and then you can see in out put file, there is a summary of particle tracking, "particles on wall..".

let me see if i understood...

i have to set 3 boundary conditions in cfx-pre? i'm kind of new in CFD.. sorry!

But for this, I need to have 3 different geometries? Like 3 domains?

hi, If I understand your problem correctly,
in cfx-pre, you have to assign 1st domain and then boundaries under domain. there you can assign 3 walls separately.

Okay! I think I got the idea!
I was wondering if there was another way to do this. But I can't think in another way!

I believe that the 3 domains will solve my problem!

Thanks so much, Sakura!

hi hi, you don't need 3 domains, you can define one domain and boundaries as,
inlet, outlet, wall1, wall2, wall3 and so on.

hi liliana
could you please explain how you calculate the mass flow of the particles using the function calculators?
thank you

In the output file, a list is present showing you the mass of particles escaping through a wall, or leaving through an outlet.

Hello Gert
Which file do you mean? My flow contains air and particle but in function calculator we can not calculate mass flow of the particle it calculate the total mass of air and particle.what is your idea?
Thank you

Every CFX calculation comes with an output file (.out-file). It contains the text that you see when running your calculation in the CFX-solver manager. At the bottom of this file you see a summary of all kind of things, including a mass distribution of all your particles when escaping on a wall, or leaving through an outlet. Please note, particles that bounce back from a wall are not included.

Thank you again
Is there this option(this file) in fluent?

Not that I am aware of. Possibly you can run a report in the Fluent GUI after running your calculation?

CFX producing an output file is one of the main reasons I use CFX all the time. I always use CFX, unless a client asks me to use Fluent.

My purpose is to produce number of escaped particle as a output parameter because i need this parameter in optimization part(NSGA-II).how can I do it?

In Fluent? I have no idea.

During a CFX-calculation, you get a summary of all particles in text format. Say, you have 1000 particles on the inlet, then 100 go to walls (escape), 800 leave the calculation (outlet), others are trapped (time of distance excape), integration error, etc.
If you have only 1 outlet, then 800 is your number.

If you have multiple outlets, you get the information as mass on each outlet, but only at the end of the calculation (bottompart of output file). If all particles have the same mass, then you can easily calculate back how many particles you have on each outlet.

Do you want to setup an automatic parameterization study with this info in the Workbench environment? Then contact ANSYS support since this is not trivial.