2D Granular Piston


This is a new experiment that I am starting up in collaboration with the University Pierre & Marie Curie, France, with researchers Evelyne Kolb and Guillaume Overlez. The purpose is to look at the role of friction in granular silos when the bottom floor is raised quasi- statically.

Above is the view of the entire apparatus with the new drive mechanism visible underneath.

This is a closeup of the connecting point between the piston and the driving plate. It is currently only pushed by the ball-bearing which is held in place by gravity. Rearrangement of the top plate will allow connection of the ballbearing via a spring (hacksaw blade) and for the capacitor plates to be mounted.

Above is a top view (as seen in a big mirror mounted above the experiment) of the 1/3 hp electric motor (bottom left) attached to a 150:1 reducer, which drives a bicycle chain.

Overhead 3/4 view of the new piston drive mechanism and ~30 kg solid steel plates holding things secure.

Images of the stress in the system at the start and after 75 seconds of pushing on the bottom with the "granular piston". Here, the total distance traveled by the piston is approximately 1.5 cm.



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