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#1 2004-09-16 19:58:02

Palomar
Member
From: USA
Registered: 2002-05-30
Posts: 9,734

Re: Traveling-Wave Engine - Deep Space Travel

http://www.spaceref.com/news/viewpr.html?pid=15063]Read me

*Traffic is a bit heavy in the Unmanned Probes folder, so thought I'd post this here, especially as it relates to plans for deep space probes

"...have developed a novel method for generating electrical power for deep-space travel using sound waves.  The traveling-wave thermoacoustic electric generator has the potential to power space probes to the furthest reaches of the Universe...The traveling-wave engine/linear alternator system is similar to the current thermoelectric generators in that it uses heat from the decay of a radioactive fuel to generate electricity, but is more than twice as efficient...Since the only moving component in the device besides the helium gas itself is an ambient temperature piston, the device possesses the kind of high-reliability required of deep space probes."

*Says it's the modern-day adaptation of the Stirling engine.  That part of the article is a bit...-whoa-.  :laugh: 

Comments?  Sounds great to me...(as if I'm qualified!).

--Cindy


We all know [i]those[/i] Venusians: Doing their hair in shock waves, smoking electrical coronas, wearing Van Allen belts and resting their tiny elbows on a Geiger counter...

--John Sladek (The New Apocrypha)

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#2 2004-09-17 12:10:54

C M Edwards
Member
From: Lake Charles LA USA
Registered: 2002-04-29
Posts: 1,012

Re: Traveling-Wave Engine - Deep Space Travel

Hmmm... You know, this could be useful for a solar collector, too.  18% efficiency is pretty good for solar power generation, better than solar panels.

This use of thermoacoustic cooling/heating is pretty ingenious.


"We go big, or we don't go."  - GCNRevenger

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#3 2004-09-17 19:11:10

Shaun Barrett
Member
From: Cairns, Queensland, Australia
Registered: 2001-12-28
Posts: 2,843

Re: Traveling-Wave Engine - Deep Space Travel

I think it would be easier to understand if they'd included a cut-away diagram or, better yet, a brief sequence of pictures revealing the mechanism at work.
    Sounds O.K., though, except for the possibility of wear between the piston and cylinder. Should we be talking to Mobil about what kind of multi-grade lubricant we'll be needing?!   tongue


The word 'aerobics' came about when the gym instructors got together and said: If we're going to charge $10 an hour, we can't call it Jumping Up and Down.   - Rita Rudner

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#4 2004-09-17 20:12:43

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 29,431

Re: Traveling-Wave Engine - Deep Space Travel

This has been around since the late 60s when guitar sound amplifiers had an experiment that used a voice coil wires inserted into a flame and it produced audible sound. My memory is somewhat rusty on the specifics but I do remember reading about this so many years ago. There is also something simular for the greek ampli-theaters stages having torches or open bowls of flame used in the same way.

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#5 2004-09-17 23:03:45

Mad Grad Student
Member
From: Phoenix, Arizona, North Americ
Registered: 2003-11-09
Posts: 498
Website

Re: Traveling-Wave Engine - Deep Space Travel

Stirling-cycle engines are great in that they're more efficient than regular decay-and-heat RTGs, but you do have to factor in that you're adding in an extra mission critical moving part. You'd want to be pretty confident that that won't break or else you'd have a lot of 'splainin' to do to Congress if it were to break down.

Actually, there is a solution that would have the best of both worlds. Perhaps the RTG could be designed so that primarily it would run off of a Stirling engine, but in the event that the engine broke down, it could run off of pure heat alone. Granted, it would be heavier, but that might be mass well spent to ensure that essential power will be provided no matter what.


A mind is like a parachute- it works best when open.

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#6 2004-09-19 13:44:25

C M Edwards
Member
From: Lake Charles LA USA
Registered: 2002-04-29
Posts: 1,012

Re: Traveling-Wave Engine - Deep Space Travel

Actually, as I understand it, this has NOT been around since the 1960's.  The newest advance described is the use of thermoacoustic cooling for greater efficiency, not the introduction of the Stirling engine.  (Although linear Stirling engines haven't been around since the 1960's, either.)  The cooling system is the neat part, not the engine.

The same principle could conceivably be applied to the thermocouples in a standard RTG, radiative cooling panels, or anything else that would benefit from a heat-engine refrigerator/cooling system with no moving parts. 

This is potentially a big advance.


"We go big, or we don't go."  - GCNRevenger

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#7 2004-09-19 14:54:28

Rxke
Member
From: Belgium
Registered: 2003-11-03
Posts: 3,669

Re: Traveling-Wave Engine - Deep Space Travel

That's, then the same system, but in reverse they tested some years ago as refrigeration unit for the big electronics on naval ships?

It was lighter smaller etc, plus almost no moving parts, and the noise, coming from two 'speakers'(horns; IIRC)  was phased to that most of the (sound) energy canceled eachother out outside the fridge...

cool tech.

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#8 2004-09-20 11:44:05

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 29,431

Re: Traveling-Wave Engine - Deep Space Travel

Spacecrafts powered by thunder
http://www.newscientist.com/news/news.jsp?id=ns99996419

Thunderous sound waves could one day propel spacecraft to the edge of the solar system, say engineers who have developed a new type of acoustic engine. The expanding and contracting gas produces sound waves - a deafening roar - that oscillate at a frequency of 120 Hertz. Puts you down in the sub woofer range of audio. Not to mention super loud.

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#9 2004-09-20 15:02:16

Palomar
Member
From: USA
Registered: 2002-05-30
Posts: 9,734

Re: Traveling-Wave Engine - Deep Space Travel

Spacecrafts powered by thunder
http://www.newscientist.com/news/news.j … ns99996419

Thunderous sound waves could one day propel spacecraft to the edge of the solar system, say engineers who have developed a new type of acoustic engine. The expanding and contracting gas produces sound waves - a deafening roar - that oscillate at a frequency of 120 Hertz. Puts you down in the sub woofer range of audio. Not to mention super loud.

*Wow, that's a really cool article.  smile 

"Their model runs at 18% efficiency - more than double that of today's space engines - but Petach says that within two years the engine could be tweaked to match the 25% efficiency of two-piston Stirling engines."

*Hey, how large (on average) are those plutonium bricks mentioned in the article?  Just curious. 

"'Inside the engine, the acoustic pressure is high enough to pop your eardrums,'  Petach told New Scientist.  'It's louder than a thunderclap.'  He adds that the sound does not escape the engine, so the device could be used to produce electricity for submarines..."

--Cindy


We all know [i]those[/i] Venusians: Doing their hair in shock waves, smoking electrical coronas, wearing Van Allen belts and resting their tiny elbows on a Geiger counter...

--John Sladek (The New Apocrypha)

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#10 2004-09-20 15:10:59

John Creighton
Member
From: Nova Scotia, Canada
Registered: 2001-09-04
Posts: 2,401
Website

Re: Traveling-Wave Engine - Deep Space Travel

Does anyone remember roboteck. One of the alien species had technology where they could use sound as a weapon.


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