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Old   August 14, 2017, 04:37
Question Counting Particles in Transient Simulation
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Hello there,

Im currently working on a Transient Particle Simulation for my bachelor thesis.

1.) Is there any way to count the Particles on Boundries over the time ?

For example:

How many particles pass the Inlet in those ten seconds of Simulation?

2.) if 1. is possible, can I get a distribution on where those particles pass a Boundry or an interface?

Im using Ansys R18.0 via Ansys Workbench.

Thanks for your help


Edit:

I searched the Ansys Modelling guide but couldnt find anything that helps.
Tried the Particle Histograms in Output Control but that gives a Histogram for each Timestep.
Expressions like count(Water.Mean Particle Number)@Inlet or sum(Water.Mean Particle Number)@Inlet didnt work either.

(Sorry if these are very basic questions but Im quite new to simulating and could find answers through Google or the Modeling/Theory Guide)

Last edited by Nuuu; August 14, 2017 at 11:41. Reason: Further Details
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Old   August 15, 2017, 03:20
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Anyone ?
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Old   August 15, 2017, 06:19
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Have you tried integrating "Particle Number Rate" over the boundary?

I don't do much particle tracking stuff, so sorry I can't help you more.
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Old   August 15, 2017, 07:17
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Are you speaking of massFlowInt(Water.Particle Number Rate)@Inlet? since I cant specify Int(Water.Particle Number Rate) to a specific boundary.

With massFlowInt(...)@... I got the following error:
No data exists for varible 'Water.Particle Number Rate' specifierd in object 'Inlet'.

Does that mean I did monitored my particles correctly ?
My particles are seeded in the Inlet and I tried to evaluate this expression in CFD-Post.

No worries. Im glad somebody answered.
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Old   August 15, 2017, 07:59
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Yes, I meant integrate in general. I left it up to you to work out exactly what form of integration and how to implement it

I would suggest you do areaInt(Particle Phase.Particle Number Rate)@Boundary.

Area integral seems more appropriate than mass flow integral, but check what basis the particle number rate is based on (volume flow rate or mass flow rate) to be sure.

Also, you need to do this operation on your particle phase, not the continuous phase. Is water your continuous phase? If so that would explain why that did not work.
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Old   August 15, 2017, 09:10
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Water is my particle Phase and air my continuous phase.

with areaInt I get the exact same error message:

No data exists for varible 'Water.Particle Number Rate' specifierd in object 'Inlet'.

The Number Rate is base on a direct Specification. I set 1 [s^-1] at the Inlet.
Even if I have this Value I still must be able to get the Value at the Outlet somehow.
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Old   August 15, 2017, 18:34
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There will be some way of getting it, but it is just a matter of finding exactly what. As I am no expert on particle tracking I cannot help you there.

But an alternate approach is to get the mass flow rate of your particle phase. If your size distribution is known you can work out the particle count from that.
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ansys 18.0, boundry condition, interphase, particle, particle deposition

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