
		HOPPER

We would like to understand a little better the outflow from a hopper which
is very frequently used in industrial setups to store base materials for
processing. The walls of the hopper are flat but the inclined side walls are
at an angle of 60 degrees and made of small balls to account for surface
roughness.


One can choose two different initial configurations:

a) all particles are of the same size as the wall particles

b) particles have a Gaussian size distribution around the size of the
wall particles


In principle, the configuration from a) is already in a stable configuration
but the ones obtained from b) do have to be equilibrated by STARTING the
simulation from the CONTROLS menu and monitoring the kinetic energy shown
in the graph area at the bottom of the window. If the energy is low enough
(smaller than 1 seems reasonable) and the particles do not move any more,
one could save the configuration for later use from the FILE menu and/or
OPEN the shutter to start the outflow sequence.

In this simulation, the colors are chosen to be proportional to the kinetic
energy of the particles and the color code is given in the spectrum on the 
side.

/*
	MolecularDynamics;
	Forces;
	Vibration;
	Billiard;
