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Re: strange behavior of particles in a glass or cup

Posted: Mon Sep 05, 2016 7:30 am
by ChristianZ
Hi Andrew,

thank you very much for this thorough error analysis and optimization! I will use these new starting values in future for Dyverso projects. Already I have applied them to the "amphora" project and indeed, it seems to fix the sticking of particles and the wall and fixes this issue.
So finally, is it a bug or feature? It seems to be a certain property of this solver that people have to know but it is possible to live with it. Nevertheless, I would recommend Nextlimit to change the default values for object interactions in the Dyverso interface.

Re: strange behavior of particles in a glass or cup

Posted: Mon Sep 05, 2016 10:08 am
by duke3d
ChristianZ wrote:Hi Andrew,

thank you very much for this thorough error analysis and optimization! I will use these new starting values in future for Dyverso projects. Already I have applied them to the "amphora" project and indeed, it seems to fix the sticking of particles and the wall and fixes this issue.
So finally, is it a bug or feature? It seems to be a certain property of this solver that people have to know but it is possible to live with it. Nevertheless, I would recommend Nextlimit to change the default values for object interactions in the Dyverso interface.



I think it's a bug :( Unfortunately it didn't help me to fix another simulation I have. After I changed "DY Interaction distance" to 1.0 everything looked ugly. Yeah, it reduced quantity of that sticky particles but not completely.
The result is https://youtu.be/G-_KSOTwgtA

Quite ugly :(

Re: strange behavior of particles in a glass or cup

Posted: Mon Sep 05, 2016 10:35 am
by ChristianZ
Yep, that seems to tip the balance to the "bug" side :(

Re: strange behavior of particles in a glass or cup

Posted: Mon Sep 05, 2016 11:48 am
by duke3d
by the way, I have the same problem with Standard particles :( It's not so strong in comparison with Dyverso particles.

Re: strange behavior of particles in a glass or cup

Posted: Mon Sep 05, 2016 12:07 pm
by ChristianZ
There is a difference regarding the standard particles: they used to work well. So either that is a new thing in RF2015 or it depends on particular settings.

What is probably not worth to continue testing is using a different daemon scale values than the default one. In my experience changing daemon scale only fixes some issues, while creating other problems for different parts of the simulation setup.

Re: strange behavior of particles in a glass or cup

Posted: Mon Sep 05, 2016 12:52 pm
by duke3d
I agree about scale ;)

I need to say that many years ago, when I first found Realflow, there was no such problem at all. I had very long break in using Realflow (10 years). So, when I checked it recently I was surprised to see many new cool tools, but I was also disappointed when I got strange particles' behavior in very simple simulation :(

Here is what else I got (standard particles):
https://youtu.be/CbQpjOfw1Po

Resolution is 20, other parameters are default.
Look are the boundaries.

Andrew

Re: strange behavior of particles in a glass or cup

Posted: Wed Sep 07, 2016 6:55 pm
by ChristianZ
At the end of the day, how should we phrase the description of this "anomaly"?
Is it the interaction with objects, and if so, is it possible to bring it back to a normal behavior by changing parameters or is there some kind of pathological stickiness?

Re: strange behavior of particles in a glass or cup

Posted: Thu Sep 08, 2016 12:23 pm
by duke3d
"pathological stickiness" :)))) sounds right