What is the Angle of Repose for Granular Materials?

[Rhysics]

For my coursework, i am investigating the angle of repose of granular materials. However, for my coursework to be. . . successful i need to prove or disprove a theory or an empirical equation which i can test. So far from my research i have not found a simple... or appropriate complexity theory or equation. So... if you know/can think of any theories or equations i can test on this area please let me know.

Background:

Angle or repose is the steepest angle of descent or dip of the slope relative to the horizontal plane when material on the slope face is on the verge of sliding.

I have 3 methods to calculate the angle of repose, each have a different setup.

An example of one - the simplest one. Is to have a funnel full of sand a fixed height above a piece of card. The sand is then released from the funnel (via a nozzle) onto the card. This will form a cone of sand, and from this cone the angle of repose can be calculated, using trig and knowing the radius of the cone. The sand is of a certain particle size, and i have 3 differing particle size sand samples to use. I will also use salt, as it is easy to get differing particle size samples to use.


Thanks in Advance


Rhys

 

[Andy Resnick]

A quick search found these:

http://adsabs.harvard.edu/abs/2005APS..DFD.HJ001D

http://iopscience.iop.org/0305-4470/29/10/016;jsessionid=0A0E1050370507AF23FA501262645598.c2

http://onlinelibrary.wiley.com/doi/10.1002/jps.2600660907/abstract

http://www.civl.port.ac.uk/britishsteel/media/BSCM%20HTML%20Docs/Angle%20of%20repose.html

http://www.google.com/url?sa=t&sour...sg=AFQjCNHCAh1-zb6va0HZEayveiGlrxrgIg&cad=rja

And a lot more...

 

[Rhysics]

unfortunately, i have already been on all those sites you suggested. But thanks for the effort