Basketful of analysis challenges

[trainguy]

All,

Any ideas of how to determine the shape and CG of granular material (known angle of internal friction)as it is being slowly dumped out of a container? I have the initial shape, before dumping.

Is this fluid dynamics?

tg

 

[GBor]

Particle physics? OUCH! I certainly wouldn't do it with FEA with any confidence. I supposed you could try to come up with a viscosity of the (fluid?) grains, but I would have zero confidence in the results and would have a really hard time presenting them to anyone.

 

[trainguy]

GBor,

Another note which may help: I am only interested in what is left in the container, of course.

tg

 

[GBor]

Then I am confused...are you trying to determine how much would be left in the container? Or just what is happening to the container based on the amount that is left? In other words, are you just trying to determine how long to pour to end up with a preset amount of "stuff" left in the container? Guess I'm clearly confused on what you are really trying to determine from the analysis -- stress in the container, time of flow, impact of flow on container, etc.?

 

[kellnerp]

First of all I would do this with a CAD system. Knowing the angle of repose you can estimate the geometry of the pile and then use the density of the material. I use SW for this kind of thing. You would not consider the material in motion because that is essentially weightless while moving.

If you want to get gnat's eyelash accurate, check Denver School of mines. I do believe they were working on a code for granular materials such as sand, ice floes, etc. Supposedly worked pretty good. But I don't recall the name of the code. Sorry.

TOP
CSWP, BSSE

http://www.engtran.com

http://www.niswug.org

"Node news is good news."

 

[trainguy]

I need stress in the container, stability of the container, (kind of like a factor of safety against catastrophic overturning of the container).

Eventually, I'd do some static FE runs in various positions as well.

tg

 

[kellnerp]

The ACI silo code has formulas for finding the wall and floor loads for granular material. Jenike and Johanson also have this.

TOP
CSWP, BSSE

http://www.engtran.com

http://www.niswug.org

"Node news is good news."

 

[johnhors]

You could try Rockfield Software

They have software to analyse particulates

see silo flow analysis (and animation when mouse-overed):-

http://www.rockfield.co.uk/part.htm#

Though worryingly, this website has not been updated for 7+ years!!

http://www.Roshaz.com