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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."
Engineers there shrunk jet engines to the size of a coat button
Naturally the Department of Homeland Security will declare that people with 4 or more buttons on their coat are 'terrorists'
Trolling is a art,
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
What about the exaust?
I can't wait to get kicked out of a snooty coffee shop because my dual core G5 laptop was asphyxiating the customers . . .
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
How many years now have we been hearing about miniature turbine power sources? Too many. Just because some kids at MIT did it doesn't mean it's even close to being commercially viable, and even if it is viable doesn't mean anybody will adopt it. That aside, I do think it's a great concept and I hope it DOES eventually get adopted, especially if they can make the turbines run on vegetable oil :)
-73, de n1ywb
www.n1ywb.com
While there are still a few hurdles to overcome...
Ya think?
Yeah? Well I think you're overrated too.
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.
"a technology which promises to free us to carry extra fuel instead of batteries"
That's just what we need, more dependence on combustable fuel. Besides that I feel MUCH safer carrying around extra batteries then a highly explosive fuel.
There was a bit of calculator one-up-manship in some of my classes, so I always wanted to connect a little model airplane engine to a little generator and use it to power my calculator during exams. Besides the roar of the non-mufflered engine (dropping in RPMs during every keypress as it consumes more power), there would be the smell half-burnt gas coming out of that little two-stroke. The intimidation factor alone would have skewed the curve in my direction.
So, wow, my silly dreams could become reality!
HIV Crosses Species Barrier... into Muppets
Also, is it going to make that jet engine noise?
Can't be worse than those low-cost P4 notebooks. Those fans can already be calles "turbine on a chip".
Life is just nature's way of keeping meat fresh.
I read somewhere that farting releases methane. May be these micro-jet engines can be powered by far gas. On an airplane, the PDA can be inserted in a pocket on the seat and just a fart will power the PDA micro-jet ;-)
TSA Drone: "What do you have in that bottle?"
You: "Oh, it's just some gasoline for my laptop."
Sure...this technology will be a GREAT laptop power source for travelers...
Do these things still make a horrid mess when they accidentally suck geese in through the intake?
If I can take 1000 of these microjets, I can convert my Beanie Propeller hat to a Beanie Jet Engine Hat and fly. Since this is posted freely and publicly, this can't be patented anymore.
Ready to take off
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Where did my body go?
WhatMeWorry!
This matters a lot, because small turbines suffer much more from viscous flow losses and heat-transfer losses than large ones. If a 50 W microturbine is 10% efficient, its waste heat will amount to 450 watts; if it is 5% efficient, the waste heat will be 950 watts! This could easily lead to them being banned from commercial aircraft, because the extra heat load and oxygen consumption would drive A/C loading too high (not to mention the discomfort of adjacent passengers).
Sustainability and energy independence essay
Beats blaming it on the dog I guess... :)
A goal is a dream with a deadline
"Each disposable cartridge would pack as much energy as a few heavy handfuls of lithium-ion batteries."
We don't really want to carry larger and larger packages of energy on our person. As it is, we are seeing accidents like this one due to today's ordinary lithium-ion batteries. And I recently got a recall notice from Verizon about the kind of batteries used in my cell phone, so this isn't an isolated incident.
When someone tosses a 9V battery in their pocket and it gets shorted out by a coin, they are startled, yell, and pick the hot coin out of their pocket.
When a cell phone battery acts up, Shelley Kaehr got a handful of battery acid and set fire to the floor.
Multiply that by "a few heavy handfuls" and you start to get the possibility of really serious personal injury.
What we need are breakthroughs on the power consumption side, not ever-increasing power supplies
"How to Do Nothing," kids activities, back in print!
take a deep breath and blow on it.
Error: Id10t detected
"Hey, what is that?"
"WHAT?"
"I said, what is that"
"MY NEW JET-POWERED MP3 PLAYER"
"cool , what are you playing?"
"I'M NOT SURE"
"There is more worth loving than we have strength to love." - Brian Jay Stanley
I hope to see a world where everything from my watch to my telephone is powered with good old Arab oil. Fuck nothing gets me hotter than imagining the day I get to pour a couple of gallons of Middle East crude into P4. A great discovery for all!
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.'"
In all seriousness, why does
Yes, this is probably off-topic (as in "not about tiny turbines") but it is still relevant. At least give us the option to ignore him.
I want to drag this out as long as possible. Bring me my protractor.
Can we please stop posting directly to stories on this guy's weblog? It's embarassing for Slashdot. The real news link you're looking for is:
here
Cept where did the energy come from to charge that 80% efficient battery? From your local gas turbine powerplant, which once you factor in the efficiency loss of the grid, will come out to much lower efficiency than your hand held gas turbine.
For as much as I love Slashdot, there exists little recourse for people who want their input on the site to be heard, even when its on as large a scale as the current hatred of Roland posts.
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Long-term storage of hydrogen is still a bit of a problem. Hydrogen has a tendency to penetrate ANYTHING you try to store it in, resulting in hydrogen embrittlement. In short, anything you store hydrogen in (esp. pressurized hydrogen) will eventually become weakened by the hydrogen permeating it.
retrorocket.o not found, launch anyway?
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...
I don't see the rationale for that, as long as they file a flight plan for their coat.
What's top speed for a London Fog?
sigs, as if you care.
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.
They've been working on this since 1993, and in 1997 they said they'd have it working in three years. In 2004, they say they'll have it working in three years.
It doesn't work yet. They can fabricate the individual parts, but it doesn't really generate power.
It's not an unreasonable idea, but if this was going to work, there should already be little gas turbine powerplants a few inches long, machined out of metal by standard techniques. The smallest turbines available weight around 1.5Kg, and are used for model aircraft, and they don't have to run for very long. There's a "microturbine" industry, but they mean 10KW units taller than a man.
Little turbines are hard. Automotive turbines and light-plane turbines have been attempted many times, but have never been cost-effective.
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/
Sustainability and energy independence essay
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).
Beats blaming it on the dog I guess... :)
A guy goes to dinner with his girlfriend's family, and finds he is a bit windy about the arse. Anyway, he is sitting down at table, and the family dog is lying down behind his chair, so he figures he'll try a little experiment. So, he shifts his weight to his left cheek, and squeezes out a fairly quiet fart.
The mother looks up at the noise, and says "Baron!" (this being the dog's name). Encouraged, the guy lets out another one, quite a bit louder this time.
Again, the mother looks up, and exclaims "Baron!" in a more urgent tone.
By now the guy figures he's got carte blanche for whatever trouser stunts he wants to pull, so he let's rip with all his might, and lets one go that sounds like the curtains are being ripped in half!
At this, the mother stands up, panic-stricken, and shouts "Baron! Get away from that man before he shits all over you!"
Call me old fashioned, but I like a dump to be as memorable as it is devastating - Bender
It takes energy to transport materials, ya know.
Candy-Coated Knowledge
is that many of the physicists working on the problem don't understand fluid mechanics at such a small scale. The viscous forces are huge compared to the inertial forces, and you have a completely different set of physics.
That's why you don't see very many working concepts of small aircraft (the kind that fit in the palm of your hand) with what most people recognize as wings. They're usually equipped with small flat-plate type wings, or a ribbon-like system like on a cuttlefish.
And the reason that many folks that do happen to understand the physics don't try and do things at such small scales is that the problem is difficult. Not impossible, but difficult.
As a person with a background in fluid mechanics, I don't see how the approach in the article will ever work well or efficiently. It might work, but it's not using the kind of principles that you need. (The whole point of my post is that you can't scale a device down without adjusting or remaking how it does what it does. The physics change.)
Remember, even the worst farts aren't 100% methane
The sun is a mass of incandescent gas... ^H^H oops sorry... wrong comment.
Here's the lowdown on fart gas content, for those interested in such things:
(source: Facts on Farts)
What is fart gas made of?
The composition of fart gas is highly variable.
Most of the air we swallow, especially the oxygen component, is absorbed by the body before the gas gets into the intestines. By the time the air reaches the large intestine, most of what is left is nitrogen. Chemical reactions between stomach acid and intestinal fluids may produce carbon dioxide, which is also a component of air and a product of bacterial action. Bacteria also produce hydrogen and methane.
But the relative proportions of these gases that emerge from our anal opening depend on several factors: what we ate, how much air we swallowed, what kinds of bacteria we have in our intestines, and how long we hold in the fart.
The longer a fart is held in, the larger the proportion of inert nitrogen it contains, because the other gases tend to be absorbed into the bloodstream through the walls of the intestine.
A nervous person who swallows a lot of air and who moves stuff through his digestive system rapidly may have a lot of oxygen in his farts, because his body didn't have time to absorb the oxygen.
According to Dr. James L. A. Roth, the author of Gastrointestinal Gas (Ch. 17 in Gastroenterology, v. 4, 1976) most people (2/3 of adults) pass farts that contain no methane. If both parents are methane producers, their children have a 95% chance of being producers as well. The reason for this is apparently unknown. Some researchers suspect a genetic influence, whereas others think the ability is due to environmental factors. However, all methane in any farts comes from bacterial action and not from human cells.
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
Combined cycle generation overcomes these limits by using water as a working fluid for the gas turbine's "waste heat". Water is much easier to compress, you just condense it and run it through a pump. The condenser makes a vacuum, which further adds to cycle efficiency. Steam turbines can expand steam all the way down to vacuum pressures and nearly ambient temperature.
The working fluid, air, in a micro turbine is going to behave in a more compressible fashion than it will in a big turbine. It should be easier to compress and suffer fewer losses due to turbulence. This will partially be offset by increased viscous losses to walls and pipes, but those can be kept low with short paths.
Friends don't help friends install M$ junk.
If you open up any copy of Encyclopædia Britannica you'll easily find articles you consider to be "biased." This is inevitable; Britannica is written by humans, and one man's "bias" is another man's absolute fact. No man willingly writes bias against his own judgment.
In the case of Wikipedia, it is not whether bias exists that matters. It is impossible to remove bias from human-made media. What matters is how that bias compares to those of other comparable media.