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Jdo300
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Hello All,
I have become interested in the study of nonlinear acoustic/longitudinal wave effects and came across this interesting article on HowStuffWorks.com which talks about Acoustic levitation:
http://science.howstuffworks.com/acoustic-levitation2.htm
On the above link, they post the following, which I found very interesting:
I am particularly interested in the third item, acoustic streaming. What I am wondering is if there is an electromagnetic analog to this phenomenon? Would it be possible to induce a DC current (closed ring) or a DC voltage potential (open loop) on a wire using a longitudinal wave directed along the length of said wire (through the space surrounding the wire, not through the wire itself). I have heard of similar effects taking place in plasmas but I'm not sure if that would apply in this case.
Any thoughts or comments appreciated.
Thanks,
Jason O
I have become interested in the study of nonlinear acoustic/longitudinal wave effects and came across this interesting article on HowStuffWorks.com which talks about Acoustic levitation:
http://science.howstuffworks.com/acoustic-levitation2.htm
On the above link, they post the following, which I found very interesting:
Ordinary standing waves can be relatively powerful. For example, a standing wave in an air duct can cause dust to collect in a pattern corresponding to the wave's nodes. A standing wave reverberating through a room can cause objects in its path to vibrate. Low-frequency standing waves can also cause people to feel nervous or disoriented -- in some cases, researchers find them in buildings people report to be haunted.
But these feats are small potatoes compared to acoustic levitation. It takes far less effort to influence where dust settles or to shatter a glass than it takes to lift objects from the ground. Ordinary sound waves are limited by their linear nature. Increasing the amplitude of the wave causes the sound to be louder, but it doesn't affect the shape of the wave form or cause it to be much more physically powerful.
However, extremely intense sounds -- like sounds that are physically painful to human ears -- are usually nonlinear. They can cause disproportionately large responses in the substances they travel through. Some nonlinear affects include:
- Distorted wave forms
- Shock waves, like sonic booms
- Acoustic streaming, or the constant flow of the fluid the wave travels through
- Acoustic saturation, or the point at which the matter can no longer absorb any more energy from the sound wave
I am particularly interested in the third item, acoustic streaming. What I am wondering is if there is an electromagnetic analog to this phenomenon? Would it be possible to induce a DC current (closed ring) or a DC voltage potential (open loop) on a wire using a longitudinal wave directed along the length of said wire (through the space surrounding the wire, not through the wire itself). I have heard of similar effects taking place in plasmas but I'm not sure if that would apply in this case.
Any thoughts or comments appreciated.
Thanks,
Jason O
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