IMO all methods of calculating the trajectory are approximate because bulk materials in themselves are not 100% consistent.

If you want to do some research get yourself a range of belt conveyors that you can run at a range of speeds and a range of materials, measure the trajectories that result, compare them with various published theoretical methods and post the results back here when you have completed them.

By all means try DEM, but you will need to feed in the correct parameters or as with any software GI=GO. ■

We have made DEM studies of cohesion and ore trajectories for water and oil binders in chutes and on large apron feeders with high collapsing ore walls.

The cohesive strength can significantly influence the trajectory, especially for slow moving belts.

If the cohesion strength can support its own mass, in such cases, you witness the ore adhering to the head pulley and the strength is judged/calculated by the particle size and centrifugal force applied.

Many have seen belt cleaners consumed by the sticky-tricky ore pile-up on the cleaner defeating their function.

In summary, DEM can do a reasonable job when you can calibrate the behavior.

It would be extremely difficult to produce a simple equation that replicates these conditions. ■