Quiet Bernoulli Levitation (Aerodynamic Levitation)

  • #1

Main Question or Discussion Point

Bernoulli levitation, or aerodynamic levitation, is a great physics demonstration. You've probably seen it before. The classic demonstration is: take a hair dryer, point it straight up, and put a ping-pong ball in the stream of air. The ping-pong ball floats in mid-air.

But, most hair dryers are loud. I want to find a way to do this demonstration quietly, so that I can talk to my students more easily while the ball is levitating. Or, maybe set it up as a display on my desk and just leave it running continuously.

So, does anyone know of a good way to do this quietly? Should I build a soundproof shield around the hair dryer? Is there another device instead of a hair dryer that produces an air stream quietly?
 

Answers and Replies

  • #2
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Yes and no. Many labs have access to compressed air at the wall. Because the pressure is generated somewhere else, it is much more quiet, but there is always some noise due to the air stream. Of cause you can always use bottled nitrogen if you have the right size pressure regulator.
 
  • #3
rcgldr
Homework Helper
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Bernoulli levitation, or aerodynamic levitation, is a great physics demonstration. You've probably seen it before. The classic demonstration is: take a hair dryer, point it straight up, and put a ping-pong ball in the stream of air. The ping-pong ball floats in mid-air.
I'm not sure how this demonstrates Bernoulli principle, but it's interesting. You can also angle the stream to cause the ball to spin and place a tube over ball to cause it to shoot upwards. Example video (all done in one take):

https://www.youtube.com/watch?v=PdT3ChUl-zk

But, most hair dryers are loud. I want to find a way to do this demonstration quietly.
Perhaps a small fan similar in size to the ones used to vent a PC case could be used. A regular sized fan and a small beach ball could be used.
 
  • #4
boneh3ad
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I would imagine that if you got a computer fan rated for high mass flow that you could probably get the kind of velocity you need if you hooked it up to a contraction.
 

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