Posted by Mike on November 30th, 2007 in heat, power generation, sound

It seems that everyone is looking for ways of scavenging power from, well anywhere. This physics professor challenged his doctoral student to improve the design of a thermoacoustic engine driven by waste heat to make sound energy. This, in turn, vibrates piezoelectric devices to generate electricity.

There are sources of waste heat everywhere, and for the most part, none are really being effectively harnessed. If someone could create a way of capturing this energy in a cost effective way, the efficiency of everything would improve. (Google “Carnot cycle” and check out the thermal efficiency of almost everything we use today. One word comes to mind: pathetic). On the other hand, thermoacoustic devices are really amazing. Sound energy (which is really mechanical in that it consists of moving waves) can be made to compress refrigerants, move liquids and generally do effective work, maybe not with blinding speed, but with impressive efficiency.

Think of accumulating a little bit of work with each vibration: eventually, enough vibration accumulates and a lot of work gets done. Even better, sound is a LOT of vibrations, and the louder it is, the more it can accomplish. I started to think about all of the places where sounds are so loud and prevalent (I, of course, am not thinking about the heat part of this article, just the sound.). What could an acoustic resonators generating electricity accomplish at an airport at the end of a runway? At a rock concert? Beside a busy highway? In a train station?(do we have those still?) How would the resonator work? Well I can’t do the inventing for you, but you’re smart, you are reading this blog. Go on, get to work…

http://www.sciencedaily.com/releases/2007/06/070603225026.htm

Technorati : heat, piezoelectric, thermoacoustic, vibration