If you could do a representative simulation with discrete elements which addressed moisture you will be the first. It might happen one day, but not in my lifetime.

Cohesiveness between fine solids, water and air involves taking on 3 phase flow. Present technology only covers 2 phase flow regimes in any accurate detail. If there is enough moisture hydraulic conveying becomes possible. If there is enough air then pneumatic conveying becomes possible. Both these are subject to well known limitations over solid particle dimensions and other complexities.

When you mention that wagon tipplers are occasionally unable to clear accretions then you have to live with it. You cannot get sidewalls steeper than vertical. If both faces are vertical then the valley angle is correspondingly vertical. Complete lock up! So you have to place inserts in the corners of the wagon. This will give you valley angles which might promote fallout depending on the friction at the face. DEA will not address this issue. It is useless to try to analyse flow which cannot exist in the first place.

Discrete element analysis can only work when the elements are in fact discrete. Damp material is not discrete. Wet material even more so.

Sometimes technology has to be thrown out of the window: for the time being. ■