Author Topic: Thermo-Acoustic Engine (Etalim)  (Read 3720 times)

Offline sanman

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Thermo-Acoustic Engine (Etalim)
« on: 02/08/2011 02:34 PM »
Came across this article in MIT's Technology Review:

http://www.technologyreview.com/energy/32267/

http://theenergycollective.com/tyhamilton/51078/etalim-s-novel-engine-could-bust-open-microchp-small-biogas-and-solar-thermal-power

I'm thinking that its rugged durable design would be suitable for space applications. I wonder what its power-to-weight ratio is?

Let's suppose we wanted to make a rover to explore the surface of Venus, like Spirit and Opportunity have done on Mars.

Venus has a nice high surface temperature, which this thermo-acoustic engine would apparently benefit from, for higher efficiency.

I'm not sure what kind of power output is generated by your typical RTG.
But if this thermo-acoustic engine could convert at ~40-50%, then what kind of payload weight could be hauled around Venus, and for how long a duration?
« Last Edit: 02/08/2011 02:36 PM by sanman »

Offline sanman

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Re: Thermo-Acoustic Engine (Etalim)
« Reply #1 on: 02/08/2011 03:04 PM »
Another thing - could this thermo-acoustic engine (essentially a variant of the Stirling engine) be useful in converting nuclear power to electricity?

AMTEC was designed for space missions, and this wikipedia article mentions that AMTEC can do 30% efficiency with the right materials:

http://en.wikipedia.org/wiki/Alkali-metal_thermal_to_electric_converter

So if this thermo-acoustic engine already has higher efficiency than AMTEC, and if it has a high enough power-to-weight ratio, then I'm wondering if it could be useful in a propulsion system. Perhaps it could be used to power a VASIMR rocket, for example.


Oh, and one more thing - the inverse of this thermo-acoustic engine would be a thermo-acoustic heat pump.
I'm wondering if this rugged device could result in more reliable refrigerators, as compared to existing compressor-driven technology.
The thing is that compressors are now a commodity-level product, and so it would be hard to compete with them on price. I suppose only specialized critical applications might make use of this new tech, like space missions.

Offline sanman

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Re: Thermo-Acoustic Engine (Etalim)
« Reply #2 on: 02/08/2011 04:31 PM »
Perhaps this is off-topic, but another propulsion application that occurred to me would be for ships.

Instead of burning coal and oil in a messy way to turn propellers, burn it more efficiently and convert it thermo-acoustically at higher efficiency to power electrically-driven propellers. Who knows, perhaps the thermo-acoustic vibrations could irritate whales enough to warn them away, to minimize collisions between whales and shipping.

Would this thing have a greater or lesser acoustic signature than existing diesel powerplants on submarines? Since high-frequency signals attenuate much more quickly, then perhaps this thermo-acoustic system would still be okay on a submarine, because it trades off amplitude for frequency. It could probably give a minimal detection signature over a distance of tens of miles. Submarines might then be the best place to develop nuclear propulsion applications for thermo-acoustics.

What else? Nuclear-electric blimps, maybe? Send one to Mars or Titan.

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