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Particle Tracing and Animation

Posted Dec 15, 2011, 12:06 p.m. EST Fluid & Heat, Results & Visualization Version 4.2, Version 4.2a 5 Replies

MRW
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Hi All,

I constructed a stationary 3D laminar flow model. I would like to create an animation of how particles would behave in the flow field I built.

I currently have particle tracing and a player set up. However, when I run the player the particles move from the inlet to the outlet with one frame step. I have not been able to create an image showing the particles when they have traveled halfway down the pipe.


I have played around with the different sweep types but I have had no success.

What should I do? I would appreciate any suggestions!
5 Replies Last Post Feb 1, 2012, 12:33 p.m. EST
E. Turk
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Posted: 1 decade ago Dec 22, 2011, 5:01 p.m. EST

Hey Mrw,

This is a late reply but I am sure someone else is having a similar problem.(you may too since you are reading this)

You need to decrease your delta_t and T in time dependent study. Delta_t is very important. If it is not sensitive enough, your trajectory lines will not be smooth enough and they may even go thru inner obstructions within the channel.

Depending on your flow velocity, (esp. in micro channels) delta_t may have to be a as small as 0.01 sec.

Do not combine your Flow study and Particle Trajectory Study. Solve Flow Study for ONLY FOR Stationary and Particle Trajectories ONLY for Time Dependent Analysis.

I hope I've been helpful.


Hey Mrw, This is a late reply but I am sure someone else is having a similar problem.(you may too since you are reading this) You need to decrease your delta_t and T in time dependent study. Delta_t is very important. If it is not sensitive enough, your trajectory lines will not be smooth enough and they may even go thru inner obstructions within the channel. Depending on your flow velocity, (esp. in micro channels) delta_t may have to be a as small as 0.01 sec. Do not combine your Flow study and Particle Trajectory Study. Solve Flow Study for ONLY FOR Stationary and Particle Trajectories ONLY for Time Dependent Analysis. I hope I've been helpful.
MRW
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Posted: 1 decade ago Jan 30, 2012, 5:36 p.m. EST
Hi E. Turk,


I've cut down my delta_t but I am still having issues.

I've attached my file. I've gone on to using version 4.2a. However, I am still having the same issues.


I would appreciate any help.

Thanks!
MRW
Hi E. Turk, I've cut down my delta_t but I am still having issues. I've attached my file. I've gone on to using version 4.2a. However, I am still having the same issues. I would appreciate any help. Thanks! MRW
Nagi Elabbasi Facebook Reality Labs
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Posted: 1 decade ago Jan 31, 2012, 10:09 p.m. EST
When I run the player with your model, as is, I see multiple frames with the particles going all the way from the inlet to the outlet.

Nagi Elabbasi
Veryst Engineering
When I run the player with your model, as is, I see multiple frames with the particles going all the way from the inlet to the outlet. Nagi Elabbasi Veryst Engineering
John H.
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Posted: 1 decade ago Feb 1, 2012, 3:01 a.m. EST
Your model seems to work for me as well. I've attached an animated GIF of the particle flow that I see.
Your model seems to work for me as well. I've attached an animated GIF of the particle flow that I see.
MRW
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Posted: 1 decade ago Feb 1, 2012, 12:33 p.m. EST
Thanks for the help.

Looking more closely at the details of the particle trajectory module vs. the particle tracing module, I've realized where I was mistaken.

I didn't see that the particle trajectory module was modeling only the x component of the particles velocities. I was expecting it to show the movement of the particles based on the velocity streamlines as is done with the particle tracing visualization.

Within the particle tracing, however, I cannot get the particles to be release from the whole inlet face. I've tried modifying the expression for the particle positioning but cannot get the YZ face to release particles. Do you have any suggestions? This issue, with the release, is partly why I was trying to use the new module in the first place.

Attached is the updated file.




As a side note, my model also will not solve for the poincare map.


Thanks for the help. Looking more closely at the details of the particle trajectory module vs. the particle tracing module, I've realized where I was mistaken. I didn't see that the particle trajectory module was modeling only the x component of the particles velocities. I was expecting it to show the movement of the particles based on the velocity streamlines as is done with the particle tracing visualization. Within the particle tracing, however, I cannot get the particles to be release from the whole inlet face. I've tried modifying the expression for the particle positioning but cannot get the YZ face to release particles. Do you have any suggestions? This issue, with the release, is partly why I was trying to use the new module in the first place. Attached is the updated file. As a side note, my model also will not solve for the poincare map.

Attachments:

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