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Two Tiny Gas Turbines
Turbines are in the news this morning. bobtheimpossible writes to point out a BBC article on a Swiss turbine that runs at half a million RPM and generates 100 watts. It's the size of a matchbook. And af_robot alerts us to an even more diminuitive gas turbine on a chip, developed at MIT, that generates 10 watts — plenty for portable electronics — and should run 10 times as long as a battery of comparable weight and cost. A commercial version is 3 to 5 years away.
It's still a mecanical conversion of a compounds to energy, with all the inefficiencies that go with it, including disposal of waste heat. Where's these fuel cells I keep hearing about?
10 props for neat, anyway.
also, can it do this?
A feeling of having made the same mistake before: Deja Foobar
Do not shake.
at half a million RPMs, what kind of damage would happen to this thing if it was put in, say, an MP3 player for a jogger?
Two postings now and the obvious question is still not answered... where the hell are you supposed to get the fuel for these things? How are they supposed to be refilled? Still nothing.
If the trend is anything like hard disk drives, the device should get tougher as the dimensions get smaller.
I'd hate to see one of these things throw off a blade while it's powering your iPod on the subway, though.
Give a man a fish and you have fed him for today. Teach a man to fish, and he'll say "WHERE'S MY FISH, YOU IDIOT?"
Not to play up to the running "beowulf cluster" gag... but could you use a slew of these to run your house?.. backup gen with 10 or 20 of these?
meh
I think it's neat that it can output upto 100watts of energy, but at what Amperage and Volt? Could I use a couple of these things to say... act as a battery charger for an electric car?
think before you write, it'll save me moderator points.
"one tankful of fuel drives the generator for about 10 hours at peak 100 watt performance"
they talk about putting these in mobile phones, but I wonder if they are gas powered how they will be re-filled. I wonder if we will end up in a situation where we have to wait for the gas man to come each morning if we run out
*''I can't believe it's not a hyperlink.''
Half a million RPM .. wow sounds fast! Hmm .. but actually .. if we look at the "velocity" .. it's probably not that fast..
.. you can probably stop this thing with your finger .. probably there'll be an angry sharp sting style pain .. but I doubt there'd be a cut (10 watts right? .. what's the potential though).
.. someone run the numbers..
Hmm the MIT one
F=ma
I could be wrong though
Is it safe to use engines like this in enclosed spaces? An airplane is a great example, but even my office with sealed window could be a problem. Anyone have more details? Similarly, it says it can run 10 hours, but how much fuel is that? My car engine could run all year if I left it hooked up to a gas pump.
-dave
http://millionnumbers.com/ - own the number of your dreams
so do these things act like gyroscopes? i realize it is a small mass, but a super high rpm generates a big L. hate to have one powering my ipod, i could only jog in a straight line...
https://www.accountkiller.com/removal-requested
I hate to say it, but RT*A. It says the device is 95% efficient.
"...The matchbox-sized motor generates the equivalent of 100 watts..." "...and has an efficiency of close to 95 percent..."
"Forgive us our trespasses, as we forgive those who trespass against us." -Jesus Christ The Lord's Prayer
Refillable butane lighters have been around for quite a while, I'd imagine this technology would have a similar refueling mechanism.
50% if you're lucky, with corresponding 50% heat to get rid of.
Deleted
Will these devices come with ear plugs or noise blocking head phones?
Power is voltage times current (amperage)
P = I*V
A transformer can alter the voltage (and thus current) to any desired level (of course it cannot up the power).
A transformer is nearly 100% efficient at this.
I would imagine a gas turbine exploding would be worse than exploding lithium batteries.
To say nothing of using one of these for dental work, as alluded to in the article. My dentist uses sand, it's a bit annoying, but doesn't rip your face apart with shrapnel if there's a malfunction.
A feeling of having made the same mistake before: Deja Foobar
A commercial version is 3 to 5 years away.
Why is is all this stuff always "3 to 5" years away?? Blisterpack these things and get them out to market already.
Take the cheese to sickbay, the doctor should see it as soon as possible - B'Elanna Torres, "Learning Curve"
So our portable energy used to come from batteries, and now its becoming gas-powered. And our large vehicle engines used to all be gas powered, and now it comes from batteries. Interesting reversal.
That's what it would take for a carnot cycle to be 95% efficient (give or take) with a room temperature heat sink. Is it really burning this hot, or is the article full of shit? (or is my thermo just that rusty?)
Is it just my observation, or are there way too many stupid people in the world?
The process begins with a tiny combustion chamber where fuel and air mix and burn at the melting point of steel.
..which is about the same melting point as silicon
Wouldn't this thing get pretty hot in my pocket?
"I told you a million times not to exaggerate!"
A battery stores all its fuel + waste products onboard. A turbine needs a bunch of extra peripheral stuff to store its fuel and waste products. Come back when you have a wholse solution.
Engineering is the art of compromise.
It takes a lot of reading to realize that none of these sub-centimeter turbines has actually run yet. Perhaps the laws of combustion physics prevent this? There's a reason why candle flames are the size they are ... see Michael Faraday's classic lecture The Chemical History of a Candle.
Imagine a Beowulf clust..I think you know the rest.
"I think that God in creating Man somewhat overestimated his ability."-Oscar Wilde
What happens after one of these has been used off and on for a few years and the materials start to fatigue? Have we all seen the videos of the CD-Roms spun on a Dremmel tool until they explode? Hint: convert 500k (or 1M) rpms into linear velocity at the outside radius of the turbine.
Never ask for directions from a two-headed tourist! -Big Bird
Ever seen the results of an uncontained turbine failure on a jet engine? Just make it 100 times smaller 10 times faster and in your pocket.
I honestly wonder who these are for. I wouldn't use a cell phone or a laptop with a gas turbine in them. The noise, the vibration, the fumes, the refill process; even in the most ideal circumstances I am too spoiled by 'good enough' battery technology.
I'd like to see more work on battery technology and more pervasive conductive surfaces so every place I set my laptop and cell phone down helps charge it.
What did you eat today? http://www.atetoday.com/
...but I'm still holding out for Mr. Fusion.
This ain't rocket surgery.
This is old... I'm not sure about being ols SlashDot news, but it is old news in general. I saw programs about this EXACT turbine on the History Channel about 6 years ago.
What people should spend the research dollars on is trying to figure out why people keep recycling old news as 'new' news and figure out how to put that to an end. *THEN* they can proceed with whatever they want.
Knowing Google's lust for data collection, the Soviet Union is still alive and well inside the psyche of Sergey Brin....
The BBC article is about a generator, not a turbine. The article merely mentions in passing that it could be powered by a turbine.
Warning: this article may contain humor, sarcasm, parody, and perhaps even irony. Read at your own risk.
...it will remain upright at all times and you can balance your cellphone on a string. :)
http://www.physlink.com/estore/cart/Gyroscope.cfm? SID=37
The best large gas turbines do about 35%.
And efficiency drops very quickly with size-- you see friction goes down as the square of the size, while power goes down as the cube. Somewhere between the size of a sausage and a hot dog, all the turbine power is going into overcoming friction.
And the biz about 1 million RPM is pure hokum-- the worlds record is a bit below that, and that was with a tungsten alloy rotor in a vacuum chamber.
Methinks some press agent was drinking while on duty.
DARPA has been funding this kind of thing for years. Small turbines have resulted. DARPA was originally trying to develop bird-sized unmanned aerial vehicles. That R&D program produced some flyable devices, but they didn't have the low cost and 2-hour endurance DARPA wanted.
DARPA-funded work at MIT resulted in some microturbine parts back in 1997. Progress has been slower than expected, but it's happening.
The microgenerator thing was intended as a military application. The idea is to have something small, maybe even wearable, a soldier can use to recharge all the battery-operated gear. Battery recharging in the field, where power outlets are rare, is getting to be a huge hassle in the US military. Current technology is to put power outlets on everything with wheels and an engine, but that creates its own headaches.
New battery? Must be for laptops!!
'Cmon? Does everything have to be "a new way to power your laptop"? First, who the hell wants a 500,000 RPM anything sitting in their lap? The high squeal resonant frequencies will be hell once it is about two weeks old. I'll pass, and I'll ask the stewardess to shut down the guy trying to use one next to me. Second, what happens when the enterprize standardizes on this thing, and you have a cubicle farm of laptops spew CO2 (and a small component of CO) into the closed office atmosphere. I'll pass, and I'll use the Worker's Compensation claim to its max if I survive the asphixiation.
The guy says that he was surprised that designing the combustion chamber turned out to be easy, but the bearings were hard. He expected it to be the other way around. Well, no shit, Sherlock? Stationary components are easy and moving parts are hard. That applies to all mechanical systems. Duh? Someone else justified the high RPM in a previous post, noting how small the rotor will be. The gyroscopic forces trying to pull the laptop from your hands when the taxi rounds the corner will indeed be small, but the forces on the rotor bearings in relation to their size will be huge. The laptop may not rip from your hands, but it will get quiet (which the taxi driver will appreciate).
How about putting one of these in a container the size of a breadbox, and mounting it above a septic tank in a small village or country farm. Have it charge a battery as it feeds off the methane produced?
Aah, change is good. -- Rafiki
Yeah, but it ain't easy. -- Simba
yay, one more reason to burn oil... awesome!
Efficiency can be a function of size in some cases. For example, cyclone separators become far more efficient when small.
If you have a tiny turbine, there is going to be less of an area for air resistence to its turning, for example. Dust would become an issue at that point, though.
The chemistry is a challenge. Complete combustion usually requires a hot enough environment, but for a tiny turbine, it might be sufficient to have a catalyst to achieve good combustion.
The article did not mention the efficiency achieved but 10 wats is tremendous for such a small thing. But to give an idea, gasoline has about 30 MegaJoules per liter. This translates to 30 KJ per ml. That means that a mililiter would power the 10 watt turbine for about 8 hours. To give you an idea, a typical cigarette lighter holds 25 ml.
I think this was an original test platform for the smaller turbine: see here.
I guess that "portable electronics" does not include notebook computers. I see that the power brick for my G4 iBook provides 65W and the power adapter for the new MacBook Pro provides 85W.
And I can't wait to read the headlines of the first bunch of software developers, found dead from carbon monoxide posoning after a long weekend of burning the midnight oil (or kerosene, butame or propane). Personal oxygen supplies may become the next big thing in office equipment.
It combusts the fuel with air to form the products that expand through the turbine. Yes it is certainly subject to Carnot limits and it is not 95% thermally efficient. There are no materials that can do 6000 deg C. (For reference this is the temp at the surface of the sun...) This is absurd. The 95% number is clueless.
The rotor of the Swiss turbine must be pretty beefy. How much angular momentum does it have at 500,000 RPM? If you've ever played with a large gyroscope, or twirled a bicycle wheel while holding onto its axle, you can see the problem. If you try to change the direction of its angular momentum vector, the thing will twist around an axis perpendicular to both its angular momentum vector, and the direction of the torque you apply. If this thing is in a laptop, spinning around an axis parallel to the floor, and you walk around a corner, the laptop could flip in a very surprising way.
Don't mess with The Phone Company. Piss them off and you'll be using two tin cans and a piece of string.
More new ways to burn gas! Just what the world needs.
I would love to see something like this on a small cleaning droid like the iRobot if the C02 output was minimal.
I d=2475131
http://store.irobot.com/product/index.jsp?product
Combustion is NOT required. It is still a heat engine.
You simply have not considered the rest of the cycle.
The falling water does work. In order to do work, the water has to be lifted, that is, work must be done. The work is done by the gases in atmosphere. The heat comes from the sun. Gases in the atmosphere absorb the heat and expand(do work).
How much solar energy is required to lift X Kg of water Y meters when the starting and ending temps are both between 273 and 373 K? A lot more than is delivered at the water turbine for each Kg that passes through! It is a *very* inefficient process for converting solar heat into electricity.
Good judgement comes from experience, and experience comes from bad judgement.
- W. Wriston, former Citibank CEO
It would be pretty cool to run a laptop for hours on a gas engine, but will I be allowed to take it with me when I fly? I can't imagine that TSA is going to allow me a small quantity of flamible liquid so I can run my laptop on the plane. What about the emissions in a closed environment?
Well, 35% is close.
A smoothly scalable power supply. THAT would certainly boost the overall efficiency of your house. When the old lady spins up her blower, the control circuits sense the load and start up additional gens until the load is matched. When she shuts down, so do the extra gens. Same for the TV, microwave, etc. No waste running, even idling, unneeded gens and dumping power!
Good judgement comes from experience, and experience comes from bad judgement.
- W. Wriston, former Citibank CEO
3 to 5 years. Close enough to gather VC money, far enough that no one expects a working model.
There are 01 kinds of cars in the world. The General Lee, and everything else.
I'll wait for my Naqahdah Generator.
First:
I would imagine if you have a few of these devices in an office they might not add that much carbon-dioxide to the air. However, what if you have dozens and dozens of people using these devices in a closed space? What does that do to the air quality over time?
Second:
We already have exploding batteries. What happens if your fuel tank or silicon engine ruptures and the contents spill on to your ultra-hot processor? How hot does a tiny combustion engine get? How prone is it to mechanical failure resulting in a fuel spill? Also, what about flying? Liquids are already restricted on domestic flights. I'm quite certain containers of gas to power your laptop will not be allowed on aircraft.
I realize this is just first generation tech. I just have a hard time believing that this is going to be a consumer usable product in a matter of years. I think it will be more like decades - if ever. It may work functionally within a number of years, but safety factors and other concerns will likely delay this technology quite a while.
how is it possible to feature a story with glaring errors. The headline talks about a gas turbine. The BBC article talks about an electrical generator.
"Fix it"
The original article (with some more information, but in German) is here: http://www.ethlife.ethz.ch/articles/neuerantrieb.h tml
the story is about a turbine and generator(spun by the turbine) together
The BBC article initially said...
[i]..on battery charge will run for 15 to 20 years..[/i]
They've only just corrected it to hours rather than years. Also, they have confused power with energy content. They say it offers 10 times the power of a battery, when what they actually mean is that it offers 10 times the energy content. I expect more from a science article.
Will these devices come with ear plugs or noise blocking head phones?
The higher the frequency, the easier it is to attenuate it.
Also: With the speed of the rotor, and thus the frequency of the noise components, well controlled, you can use a tuned exhaust port to keep the accoustic energy from escaping the engine and use it to increase the torque on the rotor. Why waste the energy as sound emission when you can use it for power?
Bantam Dominique roosters crow a four-note song. Once you've heard it as "Happy BIRTHday" you can't NOT hear it that way
These days, I drive a Jazzy 1113 power chair, using twin U1-size 12v, 40AH batteries. That's a whopping 960 watt-hours. Each battery weighs about 40 pounds, and takes overnight to recharge. I'd love to put this turbine generator in my chair, perhaps with two smaller batteries like current hybrid cars. MUCH improved range and recharging time means I might be to go places in the real world again. Shopping mall, here I'd come!
Lemon curry?
Is this going to be 50-state legal or is there going to be a separate model for Kalifornia and Taxachusetts? I don't want to break the law just to power a PDA. ;)
The Christian Right is Neither (Christian nor right). See: Matthew 23, Matthew 25, Ezekiel 16:48-50
Anyway, the scramjet is the ultimate exercize in drinking from the firehose. A normal turbo or ram jet engine has a diffuser to slow the incoming airstream to some managable subsonic value, burn fuel, and drive the turbines. Trouble is that if you are going fast enough, the diffuser gives you so much compression and inlet temperature that nothing burns -- if you go much above the flame temperature of your fuel, your combustion gases (mainly water vapor for the hydrogen-powered NASP) disassociate back into hydrogen and oxygen.
The trick to the scramjet is to only slow the incoming airstream a little bit, somehow burn fuel in a supersonic airstream, and expand the burnt gases to get more thrust than the drag created by this arrangement.
I am not a physical chemist, but I would bet that 6000 C is past the disassociation temperature of combustion of whatever fuel and air, and you are not going to operate a gas turbine at 6000 C inlet temperature regardless of what miracle materials.
Furthermore, efficient use of a 6000 C turbine inlet temperature requires very high pressure ratios -- doubt you get that in miniature.
100 watts of output power sounds goofy -- that is of the same range of my gas engine weedwacker that generates a lot of heat and burns through a good amount of fuel.
redundant post. http://hardware.slashdot.org/article.pl?sid=06/09/ 19/1717212
I'll bet your farts produce enough methane to power that teeny turbine. I'll bet they could make it so you could stick it up your butt and have two little wires running out of it. wouldn't that be great.
I also think its a realy cool concept and i belive it could lead to some realy great advancements in gadgetry.
Very stupid decision. Gas turbines are notoriously inefficient, they are not worth using without a heat exchanger. Heat Exchnagers are big and bulky and only found in ships and locomotives powered by gas turbines. Even cars are too small to house a heat exchanger, that is why the turbine car idea never flew. So there is no chance to fit it into a laptop.
One must also consider the 100+ dBa soprano scream continously produced by a half million RPM turbine (think dentist drilling) as well as the 1000+ degrees hot exhaust (for lack of a heat exchanger thereof). Fried eggs with a roasted sausage if you hold it in your lap.
A better idea would be to use reciprocating engines, especially the Stirling one, which turns slow and is extremely quiet. The swedes use it in submarines, powered by oil and liquified oxygen. It can run almost a week submerged and is even quieter than the electric motors.
If you want a turbine, use hydrogen-peroxide. That is the "Walther-turbine" steam system, which avoids most problems of the combustion turbines, but creates a set of new woes. Peroxide is both poisonous and prone to steam explosions, it was found too dangerous to be used in submarines, that is why nuclear propulsion was invented for Nautilus.
Great, instead of devoting time and energy into coming up with ways of better powering cars and other modes of transportation, we will now be adapting a version of the inherently inefficient combustion engine that has been powering them for the past 100 years to run in our laptops instead. It really sounds like the only thing this has going for it is ecomomics (which is admittedly a good thing to have going for you I suppose). I suppose that the little fuel canisters it will use will have little Shell or Chevron logos on them?
So what happens if (as all mechanical things do) the engine seizes due to old age or some other form of failure and all of a sudden you have no power even though your fuel gauge showed 86%? How often will that be happening?
i think it should be possible to build
a "flexible geometry" fusion reactor with
micro turbines.
imagine a "chain" of microturbines.
the micro-turbine power-output is only used
to generata a magnetic/electric field.
now start "weaving" a donut with chained microturbines.
What I want to know is this:
If the roter comes out of its box will it go throw my leg?