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# Transverse wave gas compressor

Flexible band + transverse wave + constriction = compression
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First, imagine a thin, springy, steel band, perhaps an inch wide and several feet long. Further, holding it by one end, and let the other end hang down. Now, shake this band by the end you're holding. Traverse waves will move down the band from top to bottom.

Next, put this imaginary band inside of a square tube, whose inner dimensions is one inch x one inch. Now, when the top of the band is shaken, not only does the band experience a traverse wave, but there are pockets of air being moved down the tube by the surface of the band.

Replace the one inch square tube with a different shape enclosure -- two (opposing) sides are one inch rectangles, the other two (opposing) sides are trapezoids, which start out quite wide at the top, and narrow down to one inch at the bottom.

When the steel band is shaken in this new shape, it still forms a traverse wave moving downwards, but the amplitude of this wave decreases as the wave moves downwards in the enclosure, and the size of the air pockets decreases as they are moved from the top of the tube to the bottom.

Assuming that air isn't leaking between the metal band and the enclosure, decreasing the size of the air pockets must compress the air in those pockets.

What does this compressor have that others don't?

A: Gas moves in a unidirectional manner, which is thermodynamically beneficial.

B: It's very easy to provide intercooling.

C: The movement of the flat surface of the band along the enclosure is more of a rolling motion than a sliding one, so not only is there relatively little friction there, but dirt particles are relatively unlikely to damage the compressor.

 — goldbb, Jul 28 2011

Lobe pump http://en.wikipedia.org/wiki/Lobe_pump
your idea reminds me of a lobe pump [xaviergisz, Jul 28 2011]

Roots type supercharger http://en.wikipedia.org/wiki/Roots_blower
[xaviergisz, Jul 28 2011]

I could be wrong about this, ignore me if I am, but wouldn't the trapazoidal ends act much like an I-beam to minimize flex in the direction you want the pump to flex the most?
 — 2 fries shy of a happy meal, Jul 28 2011

The housing is trapezoid (and does not flex); the springy steel band is still flat and bendy.
 — spidermother, Jul 28 2011

I think the steel band propagates the wave by inertia. If you use it to compress air, then the energy is taken out of the steel band quite quickly. For example, try making the waves propagate in the steel band when it is in water. However, the idea is quite brilliant in its novelty.
 — Ling, Jul 28 2011

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