PURPOSE: To demonstrate some results of vorticity and fluid forces arising from the Maxwell distribution of molecular velocities.

DESCRIPTION: Connect the end of the hose to a compressed air supply. After a few minutes, colder air squirts out the short end and warmer air squirts out the longer end. Inside the device is a cylindrical vortex cavity, into which all air is injected. The more rapidly moving molecules (warmer air) rotate at the outer radii, while the slower molecules (cooler air) rotate at inner radii. The two extremes are then directed toward the appropriate end of the tube.


REFERENCES: (PIRA 4F30.30) See Demonstration Reference File for lots of information on how these devices are constructed, how they work, and what they have been used for in the past.

EQUIPMENT: Hilsch vortex tube with base, compressed air.

SETUP TIME: 5 min.

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