The approach is no different from that used to generate the battle scenes in Lord of the Rings: each entity gets a set of rules for interacting with adjacent entities and the boundaries of the problem, and they go for it. Not very different from what Darwin came up with long ago. Here is news of a computer program that uses this approach to replicate the behavior of materials that can be modeled as discrete particles interacting with each other and with boundaries.

As so often, John Chadwick and International Mining are ahead. In the article Process Control, John provides this news of movements in the world of advanced software and engineering:

Fluent, which claims to be the world leader in computational fluid dynamics software and services, has entered into a partnership with DEM Solutions, a leading developer of Discrete Element Methods software solutions.

Fluent’s software is used to simulate, visualize, and analyze fluid flow, heat and mass transfer, and chemical reactions. A reasonable technical article that illustrates the use of their codes deals with Hydropower Turbines made more efficient. I liked the article on Activated Sludge Basin – maybe because I have tried to design one myself many years ago and that was not easy. For those who liked Pirates of the Caribbean, a similar sense of the wry will take you to A Dry Passage to the Afterlife.

DEM Solutions software is used to simulate, analyze, and visualize particle flows so that you can get a feel for what is happening in a situation involving particle kinematics, momentum, and heat and mass transfer.

Now many years ago, I used a black carbon-coated paper that I cut into a simulacrum of rock joints. I sloshed silver paint in key locations, applied a voltage and measured the potential distribution. This simple experiment got me a thesis in rock joint fluid flow. Along the way I discovered finite difference and finite element methods. Then I read Milton Harr’s book Mechanics of Particulate Media. (for sale second hand at $204—and to think I gave my copy away because it was too heavy to move!). How distant those far-from-innocent (indiscrete) times seem now that I look at the successes of discrete element software.

An aside recommendation: while compiling this piece I came across Harr’s Gerald A. Leonards Lecture. It is marvelous, the best I have ever seen, worth every second spent on it. Go to it.