Pratt & Whitney's new PurePower Geared Turbofan aircraft engines are impressive beasts. Scheduled to enter commercial service before the end of the year, they burn 16 percent less fuel than today's best jet engines, Pratt says. They pollute less. They have fewer parts, which increases reliability. And they create up to 75 percent less noise on the ground, enabling carriers to pay lower noise fees and travel over some residential areas that are no-fly zones for regular planes.
Airbus, Bombardier, Embraer, Irkut, and Mitsubishi have certified the engines for use on their narrowbody craft. JetBlue, Lufthansa, Air New Zealand, Malaysia's Flymojo, and Japan Airlines are among the engine's 70 buyers in more than 30 countries. To people outside the aircraft business, what may be most remarkable about the engines is that they took almost 30 years to develop.
The PurePower GTF began to take shape in 1988, when Pratt staffers in East Hartford, Conn., including a 28-year-old engineer named Michael McCune, started developing a gizmo to slow the fan—the big rotating blades at the front of the engine that provide most of a jetliner's propulsion. For planes flying at typical speeds, a slow fan that moves large volumes of air at a moderate velocity is more efficient than a fast-spinning fan that accelerates a smaller volume of air. (The slow fan's also quieter.)
Related Stories
The MS-21, a new single aisle airliner produced by Russia's United Aircraft Corporation, is the first passenger plane borne aloft by lightweight carbon-composite wings built without a costly pressurized oven called an autoclave.
[...] Under the new technology, instead of using fiber that is pre-impregnated with resin, parts are made from a dry-fiber engineered textile which is placed in a mould and then infused with resin under a vacuum.
The parts can then be cured in an oven without pressure, a process estimated to cost 25 percent more than metal. Ultimately, that gap needs to narrow significantly or disappear.
Boatbuilders and windfarm makers have used this method for years. Secondary airplane parts have also been made that way.
But although Canada's Bombardier partly used the technique for its CSeries, it was rare for flight-critical parts before the designers of the new Russian plane chose it for the wing.
previous stories:
Irkut Shows New MC-21 Airliner
The Little Gear That Could Reshape the Jet Engine
(Score: 0, Offtopic) by MichaelDavidCrawford on Sunday October 18 2015, @05:39PM
I have a Core Quad Xeon e5400. I bought it with the heatsink and cooling fan in one package. That fan sounds like a turbojet, even when my computer is idle.
What is particularly annoying is that it often speeds up and slows down - like every five or ten seconds - thereby drawing my attention.
How about a larger, slower fan? There's room for it in my case.
Does it really need to spin so fast when my computer isn't doing anything? I'm running Linux Mint 17.1.
I will say that the recent Linuxen run a lot cooler than do older versions.
Yes I Have No Bananas. [gofundme.com]
(Score: 2, Interesting) by Corelli's A on Sunday October 18 2015, @06:44PM
I build myself a new desktop PC about every four years, and I'm not a gamer/performance modder. However, I did put an Enermax ETS-T40-TB cooler ($35 at newegg) on my Xeon E3-1231v3 and I never hear it even with all cores running full-out. For some reason newegg shows this cooler now for some ridiculous price. Maybe a tropical cyclone wiped out the major fan factories recently.
(Score: 2) by Freeman on Tuesday October 20 2015, @07:32PM
I have noticed that the parts I purchased for my last build also went up. I'm guessing something to do with trying to push newer technology. Supply / Demand and scale of economics, perhaps? Newest thing sells like hotcakes, because it's being pushed. So, the newer thing is cheaper to produce than the older thing?
Joshua 1:9 "Be strong and of a good courage; be not afraid, neither be thou dismayed: for the Lord thy God is with thee"
(Score: 5, Funny) by davester666 on Sunday October 18 2015, @06:50PM
you may not be doing much on your computer, but I am. Thanks for the bitcoin.
(Score: 4, Interesting) by shortscreen on Sunday October 18 2015, @07:52PM
Sometimes I would unhook a fan from 12V and wire it to 5V to run more quietly (assuming the part wasn't in danger of overheating).
Can also go the other way, hook the black wire to -5V so now it is running faster at 17V for overclocking and whatnot.
(Score: 1) by nitehawk214 on Monday October 19 2015, @02:40PM
At first I thought you meant "overclocking the fans".
Now that is badass.
"Don't you ever miss the days when you used to be nostalgic?" -Loiosh
(Score: 5, Funny) by Gaaark on Sunday October 18 2015, @06:27PM
Was Volkswagen involved in the testing?
--- Please remind me if I haven't been civil to you: I'm channeling MDC. ---Gaaark 2.0 ---
(Score: 3, Informative) by Techwolf on Sunday October 18 2015, @08:14PM
While I know the above was said in jest, Volkswagen really needs to start touting that there engine uses less fuel, therefore pollutes less.
(Score: 2) by Whoever on Sunday October 18 2015, @10:05PM
Actually, in 2008, VW did tout that that their cars used less fuel and produced more power in real-world driving than on the EPA test. This should have been a strong tip-off that something was very wrong because cars almost universally produce real-world economy figures that are worse than the EPA tests show.
(Score: 2, Interesting) by meledian on Sunday October 18 2015, @07:27PM
This sounds closer to a turboprop hybrid than a turbofan. Turbo fan engines already slow the fan with a split axle/core. The n1 section is the fan and aft exhaust, while the n2 is the smaller inner section that is fore and aft of the combustion chamber. This sound more like an accessory gearbox driven fan section.
(Score: 5, Informative) by frojack on Sunday October 18 2015, @07:47PM
Yes, if you read half way down TFA (ya, I know...) you find this:
The solution McCune and his co-workers pursued was one that had already been used successfully on turboprop planes: a gearbox between the shaft and the fan that lets the fan run slower while the compressor and turbine run faster.
It goes on for a couple paragraphs explaining why/how this differs from turboprop applications.
Oddly, the engine is too big for a 737, but fits much smaller planes from Bombardier, Embraer, and Mitsubishi, due to their high wing design.
No, you are mistaken. I've always had this sig.
(Score: 5, Informative) by Whoever on Sunday October 18 2015, @08:15PM
I don't know why you would think that this was odd. That was my first thought when I read the summary: bigger engine -- it's going to be too close to the ground. The 737 has a rather odd shaped engine to keep the bottom of the engine high enough to avoid ingress of stones or other debris.
(Score: 2) by Runaway1956 on Monday October 19 2015, @01:31AM
"oddly, the engine is too big for a 737,"
I got hung up on that bit myself. It's probably a safe bet that the next airframes to be designed will place the wings high enough to use newer engines with this geared fan. Seems counterintuitive to position engines lower to the ground anyway, because of dust and trash on the ground.
Abortion is the number one killed of children in the United States.
(Score: 0) by Anonymous Coward on Monday October 19 2015, @07:48AM
(Score: 1) by Osamabobama on Monday October 19 2015, @04:41PM
Having engines closer to the ground facilitates maintenance, as the technicians can reach the engine without complicated lifts or scaffolding. That saves time, which, as we know, is money.
Appended to the end of comments you post. Max: 120 chars.
(Score: 2) by frojack on Monday October 19 2015, @09:39PM
I suspect all it will take is another version of the engine, slightly scaled down.
It probably doesn't need to be that big.
Engine maintenance on your typical 737 often requires technicians to get on their knees or lay on their back.
http://www.iasa.com.au/folders/Safety_Issues/FAA_Inaction/whosdoinyourmaint_files/cfmD20cd.jpg [iasa.com.au]
http://www.gettyimages.com/detail/photo/engineer-inspecting-new-boeing-737-engine-high-res-stock-photography/984488-001 [gettyimages.com]
Its entirely possible the trend has swung too far.
No, you are mistaken. I've always had this sig.
(Score: 2) by bob_super on Monday October 19 2015, @05:47PM
> Oddly, the engine is too big for a 737, but fits much smaller planes from Bombardier, Embraer, and Mitsubishi, due to their high wing design.
Yo man! Ya need that sucker lifted? I got a crew that gonna do a killer job!
Another 2 or 3 feet at the back, 40-inch chrome rims with low-pro rubber, hydraulics at the front to kneel it when you want to hop in, matte black spinners and as much gold as you want, yo!
Next week I get those great kits so we can mount an A380 engine on your Falcon 900X, man! Coolest ride on the block!
(Score: 0) by Anonymous Coward on Sunday October 18 2015, @07:46PM
No spinning parts to worry about. Getting off the ground may be a problem though.
(Score: 0) by Anonymous Coward on Sunday October 18 2015, @09:30PM
Solid fuel rockets.
(Score: 1, Funny) by Anonymous Coward on Sunday October 18 2015, @09:43PM
Jebediah Kerman approves this message.
(Score: 0) by Anonymous Coward on Sunday October 18 2015, @10:16PM
Or electomagnetic sled similar to aircraft carriers. You could use a longer runway than your typical carrier of course so take off doesn't have to be quite so violent (although I would pay extra to experience the Gs, I don't think most commercial customers would).
(Score: 4, Interesting) by subs on Monday October 19 2015, @05:10AM
Geared turbine engines aren't something new, not even geared turbofans. All turboprops as well as turbine helicopters are geared and geared turbofans have been in use for at least 40 years (e.g. Garrett TFE731 and the Lycoming ALF 502). Of course, all of the older geared turbofans were for smaller engines, because they're easier to design (lower gearbox loads) and get more benefit, because the turbine-speed to fan-speed discrepancy grows the smaller the engine is. The discrepancy is actually relatively small for really big engines like the GE90 and GE-nx. There are other design approaches how to limit fan speed, e.g. by using triple-spool designs (started in the Rolls-Royce RB211 and continuing in the Rolls-Royce Trent line, among others).
So all of this is just a happy marriage of technology and market demand. The design for a 20,000 hp reliable gearbox is finally feasible and fuel is sufficiently expensive that the small benefit that small engines get from it make it worthwhile.
How exactly they can claim that it has fewer parts, though, baffles me. The PW1000G appears to have all the parts of a two-spool turbofan PLUS a gearbox. There's not many engine designs simpler than a straight-up single-spool turbojet. They might be able to reduce the number of turbines, so maybe that's why they're claiming that? IDK.