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Re: hello? -help with a spinning bucket!


"There is a critical timestep for the integration, etc..."

indeed, I noticed this..  a factor of 10, and even 5 in the time-step makes the difference between particles staying put, and flowing through the bottom of the conatiner as if it wasn't there!

As for calibration,  I am not entirely sure I know what you are refering to.  Of course, defining my parameters is obvious enough, but is there a specific place and method of displaying them that you are refering to?  ie, is there some facility in paraview that you use to display this information alongside the simulation?  I will look into it..

Another question is the angle of internal friction.  from what I can tell, there are professional devices for measuring this, but there are also many others.  It seems to me that if I put some beads into a container, then tip the container, the angle at which they start flowing is the angle of internal friction..  I am not at all sure of this, it seems far to simple.  As always, I will continue looking into it.


-Mike :)

--- On Thu, 7/8/10, Anton Gladky <gladky.anton@xxxxxxxxx> wrote:

From: Anton Gladky <gladky.anton@xxxxxxxxx>
Subject: Re: [Yade-users] hello? -help with a spinning bucket!
To: yade-users@xxxxxxxxxxxxxxxxxxx
Received: Thursday, July 8, 2010, 4:59 AM

One of the task, what I am working now is a screw conveyor simulation.
It is not like your spinning cylinder, but something more-less similar.

I am satisfied with first results. Of course, there are some problems, but they always exist.

So, I think you should dive into code a little bit, make calibration, parameters defining etc...
You should prepare for long monotone painstaking work, which will bring good results.
Good luck!

2010/7/8 Václav Šmilauer <eudoxos@xxxxxxxx>

> on the first look, your model requires calibration (physical

> parameters, time-step etc.).

> Calibration is a very important part of work.

Yes, I second that.

There is a critical timestep for the integration, but depending on the

velocity magnitude of your particles, you might have to make the

timestep smaller, otherwise pathological effects like unstable

interactions (which can lead to leaking a particle through a facet)

might occur. Try decreasing it 2x or more and you will see if it makes a

difference. I was not sure if there were some particles going through,

since most or all are going through the top.


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