A granular bed under vibration. We can see the gap in the bottom and a very disperse phase in the top:
Grains falling to create the initial state for simulations:
The rising of a hevy intruder 4 times bigger than the grains:
The sinking of a light intruder 8 times bigger than the grains:
Two heavy intruders rising:
Two light intruders sinking:
Reverse Buoyancy effect:
#Granular Leidenfrost Effect
Granular temperature behavior in the granular leidenfrost effect:
Granular temperature behavior in the granular leidenfrost effect (another angle):
Bed's volumetric density profile (low density bottom and high density first bubble). The second bubble is easy to see returning to the main bubble in t~400 and reappearing in t~700. It is always less denser than the main bubble.
Granular temperature profile with the second bubble (Very hot bottom and cold first bubble. The second bubble is rather warm:
Another example of the double bubble.