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-   -   particle number concentration in OpenFOAM (https://www.cfd-online.com/Forums/openfoam-programming-development/80493-particle-number-concentration-openfoam.html)

mayank.dce2k7 August 22, 2013 12:04

I found answers to all my queries. Below thread was really helpful:

http://www.cfd-online.com/Forums/ope...r-airfoil.html

Thanks Yogesh for providing a hint.

Cheers,
Mayank

mayank.dce2k7 August 27, 2013 16:26

Hi Yogesh,

Sorry to disturb you again.

Now, I am trying to calculate deposition of particles on tube wall. So what changes should I make to 'localInteractionCoeffs' such the particle sticks to the wall as soon as it touches it and also want to count those.

Regards,
Mayank.

ybapat August 28, 2013 00:23

Hello ,

For 'wall' write in localInteraction

wall
{
type stick;

}

Regards,
-Yogesh

mayank.dce2k7 August 29, 2013 15:37

Hi,

I have a problem and I am trying for many days. I am doing one way coupled(in a bifurcating tube with one inlet and two outlets) simulation using icoUncoupledKinematicParcelFoam with pre-defined steady state velocity field . Diameter of INLET is 6mm and that of OUTLET1 is 4mm and OUTLET2 is 6mm. I am injecting 10,000 spherical particles of 0.6mm diameter the ratio of particles coming out of OUTLET2 to OUTLET 1 should be close to 1 but I am getting way higher particle ratios. I have tried mesh refinement, ratio are getting worse. I have tried changing the fluid, initial particle velocities and steady state fluid velocity field and nothing helps! Please anybody can comment and give an idea for changing things. Same simulation done on CFX and fluent yield satisfactory results.

Regards,
Mayank

mayank.dce2k7 September 4, 2013 11:45

Hi,

1.) In 'kinematicCloudProperties' what does below means:

'coupled true/false;'

what difference will true or false make?

2.) I want to give initial particle velocity same as the velocity of fluid? How can this be done, since my inlet velocity profile is a fully developed parabolic one for fluid phase and I want particles to follow the same profile that is at inlet? The option available for specifying initial velocity in 'kinematicCloudProperties' file is:

U0 (0 0 0); // it will take only uniform velocity profile

Can groovy expression be used here?

Regards,
Mayank

mayank.dce2k7 September 9, 2013 18:32

Hi Foamers,

How can I give 'U0' (in kinematicParticleProperties) in form of a table specifying each particle's velocity ?

Regards,
Mayank.

rafab April 30, 2014 09:19

Particle inlet velocity
 
Hi Mayank,

Did you find the answer to your question? I'm struggling with the same problem.

Best regards
rafab

mayank.dce2k7 April 30, 2014 13:21

Hi,

I guess you are referring to this question:

How can I give 'U0' (in kinematicParticleProperties) in form of a table specifying each particle's velocity ?

You can use KinematicLookupTableInjection...here you can specify properties of each particle.

Regards,
Mayank.

rafab April 30, 2014 13:37

Yes, that's exactly what I asked about and what I need.

Thanks a lot. It will help me a lot

Cheers
rafab

Alaska1964 May 28, 2015 09:22

Quote:

Originally Posted by mayank.dce2k7 (Post 448371)
Hi Yogesh,

Sorry to disturb you again.

Now, I am trying to calculate deposition of particles on tube wall. So what changes should I make to 'localInteractionCoeffs' such the particle sticks to the wall as soon as it touches it and also want to count those.

Regards,
Mayank.


Dear Mayank,
Did you find answer for your problem? I have the same problem.
I am simulating droplets in a L shape channel. I am using the following conditions:
patchInteractionModel localInteraction;

localInteractionCoeffs
{
patches
(
WALL
{
type rebound;
e 1;
mu 0.9;
}
);
}

In my log file it is reported that:

Parcel fate (number, mass) : patch WALL
- escape = 0, 0
- stick = 0, 0


I want to count the number of droplets deposited on the wall. Ho can Count it ? Shall I add a specific command in kinematicCloudProperties to show the number of droplets deposited?
Cheers,

Subhasree December 23, 2015 07:14

Calculation of particle deposition
 
Hi Everyone!

i have used icoLagrangianFoam to simulate a 3-D flow over an object. Can anybody tell me how may I calculate or plot the number of particles deposited on the object?

Subhasree January 4, 2016 01:17

Number of Particle Deposition
 
Hi Everyone!,

Can anybody suggest me how can I calculate the number of particle deposition on an object? I am using icoLagrangianFoam solver in foam extend-3.1

wyldckat January 9, 2016 15:12

Greetings to all!

Subhasree and Alaska1964: Can either one of you provide more details of how exactly the particles are deposited in the object's surface?
More specifically, is there a small tutorial case I can look at (and test with) to see and study this effect?

I ask this because if the particle is "frozen" on the wall surface, then it's possible to create a counter that counts the number of particles that are frozen on a particular patch. AFAIK, OpenFOAM and foam-extend don't have yet such a utility, but it should be simple enough to do, based on the already existing utilities that OpenFOAM/foam-extend have got.

Then again, swak4Foam might already have something for this...

Best regards,
Bruno

Subhasree January 11, 2016 03:48

Thanks a lot Bruno,

Actually I could not find any tutorial as such, on particle deposition or icoLagrangianFoam solver. I have used option 'stick' on the object wall instead of 'frozen'. Also, according to some of the online blogs this should give me a counter of the number of particles that are stuck and number that escaped on residual terminal..but I am not very sure of this.
I was basically looking if there is a way to post-process using paraFoam to show the number of particles deposition.

Subhasree February 8, 2016 23:37

Particle Deposition
 
Hi,

I am simulating 3-D particle flow over an object using icoLagrangianFoam solver and would like to find the number of particles deposited on the object. I have used keyword "stick" in LocalInteractionCoeffs of kinematiccloudProperties but after simualtion is complete it is not showing the number of deposited particle.

Please Help!!!:(

Subhasree February 20, 2016 01:17

1 Attachment(s)
Hi everyone,

I am working on particle deposition on a surface using icoLagrangianFoam solver. I have meshed a .stl file using snappyHexMesh and then simulated it. Although my simulation was running fine and showing the particle deposition in the post-processing file it is not moving forward after 10.95 sec. I think its getting stuck there. It is not showing any error message in the residual log file. System is showing it is running the solver but it is not moving after 10.95 sec.

I am running the simulation in parallel processor. I am attaching an image of the log file. Can anyone suggest how may I proceed to solve this problem?

I have checked the mesh using checkMesh, and it not showing any error.

Alaska1964 February 22, 2016 10:09

Dear All,

Thank you for your interest to help in advance. My problem is solved.

I have changed the particle wall interaction to patch wall stick which means particles will deposit on the wall once they touch it. In this case there is no problem, I get the number of sticked particles in the log file.

Best regards,
Alaska

kou1shik March 30, 2016 07:51

You can use cloudFunctions in constant/kinematicCloudProperties. Use like this.

cloudFunctions
{
patchPostProcessing1
{
type patchPostProcessing;
maxStoredParcels 1e07;
patches ( outlet );
}
}

hojjat.m April 1, 2016 10:22

Number of particles in each cell
 
Hi foamers,

I am using solidParticle class and I am trying to calculate the number of particles in each cell at certain times. I want to combine all of the particles in a cell. Any suggestions?

Thanks,

chpjz0391 May 12, 2016 22:55

Quote:

Originally Posted by hojjat.m (Post 592889)
Hi foamers,

I am using solidParticle class and I am trying to calculate the number of particles in each cell at certain times. I want to combine all of the particles in a cell. Any suggestions?

Thanks,

Have you found the solution for your question? I met the same question as you .


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