Slashdot Mirror
Jet Engine on a Chip
Roland Piquepaille writes "Today, our handheld devices are powered by batteries, which are heavy and inconvenient. Fuel cells are just arriving on the market as a replacement. But there is a new contender: micro gas turbine engines under development at the MIT. Engineers there shrunk jet engines to the size of a coat button. And their blades which span an area smaller than a dime can spin a million times per minute and produce enough electricity to power your PDA or your cell phone. While there are still a few hurdles to overcome, these micro turbine engines should be operational in two or three years, with commercial products available four years from now. These micro jet engines also have the potential to free soldiers or travelers from carrying heavy batteries. The engineers even think their engines on a chip could be used in poor countries to bring electricity there. This summary gives you the essential details about a technology which promises to free us to carry extra fuel instead of batteries."
1. That's pretty damned cool. Gas Turbines are some of the most efficient fuel -> energy converters known to man.
2. Saying that a Gas Turbine == a Jet Engine is a bit misleading. It's a bit like saying "Scientists have shrunk an electric motor to 4 nanmometers", then before you even finish thinking about all the MEMS devices, you read "Scientists have produced a 4 nanometer electric genertor for use in making power for MEMS devices." Still very cool, but not the same thing.
Javascript + Nintendo DSi = DSiCade
Fantastic! Glad to see a post by you Roland! You see, I really enjoy absolute shit, so I am glad to see another of your presumably bought and paid for fluff stories.
I used to bulls-eye womp-rats in my pants
What about pollution from this? Has that even been considered?
http://science.slashdot.org/search.pl?query=Rolan
This is exactly true. Roland Piquepaille submits fluff stories to /. over and over and over just to generate traffic to his blog. Slashdot ... come on. You can do better.
KARMA TAG! You're it.
What about hydrogen? I know that's kind of a played-out concept but look at the possibilities. You could have your own electrolyser at home and bottle your own hydrogen, then slap it into your laptop and go. You could generate the electricity off the grid, or whatever. Output is water vapor, which is pretty harmless as long as it's exhausted outside the case of the laptop.
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
Using the generator as a starter motor is probably the absolute best way to go. This is probably coming on automobiles, too; we'll end up with a combination AC motor/alternator-generator for starting and charging. This will be driven by everything and I mean everything on the car going electric. No more vacuum lines, no more hydraulic system. The system will be higher-voltage (automobiles are about to go 48V, even in the US) and that will reduce the gauge of wire necessary for the electrical system, further saving weight. Doing this would allow us to eliminate all the pulleys and belts on the vehicle. This will require using higher-technology batteries, like the Optima types, because electrical system problems (especially battery failure) are the #1 cause of breakdowns.
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
What about noise? A physical device spinning that fast is going to produce hypersonic as well as audible noise. Phase I: Put jet engine in cell phone. Phase II: ? Phase II: Profit from putting even smaller jet engines in hearing aids.
My user name was a mistake. Input wasn't restricted, my bad.
1. That's pretty damned cool. Gas Turbines are some of the most efficient fuel -> energy converters known to man.
You will also notice that (in general) the smaller the gas turbine, the less efficient.
I have been to multiple talks on these engines, I used to work for one of the industry colaborators on the project as an aerodynamicist. These engines are no exception to that rule. The turbine on these engines hardly extracts enough work to run the compresser when you are running the combuster just below the melting point of the engine.
Also (addressing the summary, not the parent post), these things have been "2-3 years away" for at least 6 years.
"I'll have a Guinness, no wait, make that a Coors Light" -Grad student I work with, who shall remain anonymous...
A better TR article blasts "hydrogen hype" but in fact H2 would be about the best fuel for these little buzzers:
- a fuel spill will dissapate very rapidly
- the byproduct, in answer to the questions posted re pollution is just water.
A set of bearings however will be an awsome thing to handle the gyroscopic reaction torques as you wave your jet powered cellphone about. You turn the corner, the phone does not. I don't have my old physics books handy but the linear velocity of a point on the tip of a blade isand is changing direction 180 degrees about 2000000 times a minute. The F=MA to pull this constant direction change will be staggering unless M is damn near zero.And aren't you just all breathless, when the "batteries die", to take your cellphone to the out-of-work airline mechanic who got re-trained at a watch factory ?
SLASHDOT: news for people who can't concentrate on work or have no life at all and got tired of yelling back at the TV.
While this is not exactly basic research, I think it is the kind of research that ends up contributing to something a little more realistic rather than being used itself. A lot of people here are very critical of the jet engine but keep in mind that new technologies do look a bit strange in the beginning and it may be that this engine is simply a step in the direction of something proves very useful.
http://www.busyweather.com/
I'd like to add something to what you said...
Jet engines are relatively inefficient at low speeds but once they get up to speed, the efficency goes back up and the process feeds on itself becoming a self-sustaining process.
Combustion engines are the opposite, they run fine at regular speeds but at high speeds, you get the same effect as the economic term "diminished returns" where it states that with additional units of work provide lesser and lesser additional power. In other words, it requires more and more work to achieve the same speed increase.
The only time I listened to Jay Leno was when he was talking about the difference when showing off his jet bike (a motorbike with a jet engine instead of combustion engine).
the trick is, turbines are ten times more powerful per pound, but, unless you are using waste heat recovery (steam plant?) they are 1/3 as efficient per horsepower. On the other hand, it's true that a significant portion of that would be worthwhile, so as to not have to haul around a 300lb motor, rather instead a 30lb motor. But, given the number of cars, you'd better stick with the most efficient method possible.
By now it should be clear that Roland is either one of the slashdot editors in disguise, or a close friend of one of them.
If God had had a computer it would have taken him 7 months to create the earth...if he even bothered to do it at all.
You are aware that the new generation of diesels don't stink, and some produce cleaner output than input. Also, with biodiesel, you can select you smell, from peanut oil based diesel to burger grease based diesel.
Food not Bombs is a nice platitude but it breaks down when you notice that the Bombees are usually well fed
I'm here a lot. I see he gets a lot of things accepted. Does it bother me - No it certainly doesn't, the things he finds are cool and certainly newsworthy.
i lle+writes%22+site:slashdot.org
I would rather see good articles posted under Rolands name than half the other crap weve had recently.
Yet again, I must point out that the summary he places at the bottom of each submission is just that - a summary, the main articles ALL have real links which don't involve going anywhere near his blog. Infact, I tried to find a submission of his that forces you to pass through his blog to reach the article, just to see if I had infact missed something, but I couldn't see any. Perhaps you could show me.
http://www.google.com/search?q=+%22Roland+Piquepa
I can see the point in getting irate about ny times or other registration sites where the article is posted, but I just see his blog as a bit of a mirror.
liqbase
1 million RPM at the diameter of a dime.
An American dime has a diameter of 17.91 mm.
At 1 million revolutions per minute, a point on the edge of the turbine blade will travel:
or
56,265.9 meters per minute, or 937.8 meters per second.
The speed of sound at sea level is 340.29 meters per second.
So this thing's blades will have a tangential velocity of mach 2.76.
I think the sonic boom when it starts up will be as much if not more of an issue as the whine from its operation...
Don't underestimate the power of The Source
There is no input. The staff here are completely against reader input, they're only interested in pure profit.
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More Proof?
The post in which someone criticised the moderation system that received many hundreds of downmods - the only post ever to receieve that many - something only the editors of
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