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Boeing's Hybrid Electric Airliner of the Future
fergus07 writes "Borne out of the same NASA research program that gave birth to MIT's D 'double bubble,' Boeing's Subsonic Ultra Green Aircraft Research (SUGAR) Volt concept is a twin-engine aircraft design notable for its trussed, elongated wings and electric battery gas turbine hybrid propulsion system — a system designed to reduce fuel burn by more than 70 percent and total energy use by 55 percent. The goal of the NASA supersonic research program is to find aircraft designs that will significantly reduce noise, nitrogen oxide emissions, fuel burn and air traffic congestion by the year 2035."
The S is for super and the U is for unique!
All the coolest technology is always now()+25 years away.
The other planes....I just imagined the airline packing those suckers and having more than one middle seat. And you know they'll be charging extra for the window or the isle seat.
RIP America
July 4, 1776 - September 11, 2001
You say you want to save massive amounts of energy, and then you show me a design that is not a flying wing. Slashdot, you have some aerospace engineers lying around, so help me out: what gives?
For the pictures, it looks like the subsonic airplane is equipped with turboprop engines - or are these propfans ? If so, our next generations airliners might very well be equipped with propellers again: Airbus is also considering propfans.
Boeing's Subsonic Ultra Green Aircraft Research (SUGAR) Volt concept is a twin-engine aircraft design notable for its trussed, elongated wings and electric battery gas turbine hybrid propulsion system
I think they just should have tried a less ambitious project, like building a Flying Car, instead.
"Ultra Green?" So what's the superlative for that? "Giga Green?" "iGreen?" Or what?
Schroedinger's Brexit: The UK is both in and out of the EU at the same time!
This isn't useful unless I can drive it on the roads.
Who would win this election: Andrew Weiner vs Andrew Weiner's weiner.
I had 'jet fuel' as on my list of things that wouldn't ever likely get replaced with electric storage, and now this reduces the list a bit. Can we just start putting up some modern nuclear reactors and get out of the Middle East then? We've got plenty of sources here for real oil needs.
No one has died of a radiation-related accident in the history of the U.S. civilian nuclear reactor program. but 10,000 or so Americans have died so far as a result of making war in the Middle East.
My God, it's Full of Source!
OUTSIDE_IP=$(dig +short my.ip @outsideip.net)
LH2 tanks require more insulation (meaning more weight). The planes can only carry so much fuel by volume. The maximum fuel capacity for a 737-NG is 26,000 liters. The density of Jet A at 15C is about 800g/L. The density of liquid hydrogen is 71g/L at 20K. At these densities, you get masses of about 21,000kg of Jet A and 1900kg of LH2. The specific energy of Jet A is about 43MJ/kg, and 143MJ/kg for LH2. At those levels, you get total stored energy of about 1.1 million MJ for Jet A, and only 270,000 MJ for LH2.
The numbers just don't work, and these don't consider the complicating factors from dealing with cryogenic fuels.
You can never go home again... but I guess you can shop there.
They tried building a hydrogen powered spy plane back in the 70s or something. LH2 is kind of a nightmare to deal with compared to jet fuel. For one thing, its a cryogenic. The US Air Force decided that playing with LH2 was a) too dangerous and b) too much of a logistics headache. And even with LH2, your energy density is still significantly lower than jet fuel. They had a nightmare trying to get the range required on that spy plane. Wiki-link for you: http://en.wikipedia.org/wiki/Lockheed_CL-400_Suntan. If you're interested, try finding Ben Rich's Shunkworks. He spends a chapter talking about trying to build this thing (and all the wonderful fun they had playing with LH2... they apparently went ahead and did all the usual Liquid Nitrogen fun stuff... except with LH2).
So what is the advantage of a hybrid plane? Unless there has been some sort of breakthrough in battery technology, the extra weight your carrying around is going to use more energy. A discharged battery is not substantially lighter than a full one, whereas with liquid fuel tanks weigh a lot less when (nearly ) empty..
I guess you can get a bit of energy back on landing with regenerative braking, but not enough to make up for the extra weight.
Battery weight could certainly be an issue. I suppose though that you could start off fully charged on the ground and use that for a boost to get you aloft.
Something that comes to mind is that, AFAIK, in a hybrid system you try to keep the combustion engine turning at it's ideal RPM regardless of load. Assuming that's the case, would there be periods where you might have extra capacity beyond what's needed for the electric motors and other electrical systems? Let's assume there is - what do you do with it? Is there a good use for it? How about running an ozone generator in the upper atmosphere?
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Not to be pedantic, but... OK, I'll be pedantic.
The long tube supporting the wing (on the ground) is called a strut, not a truss.
What surprises people is that the strut actually holds the wing down in flight. Saves you the weight of designing for massive bending moments at the fuselage at the expense of more drag in flight.
That was the trade off the Gossamer Condor made to become the first human powered aircraft to pass whatever milestone it did - rather than take the weight associated with an internally braced structure, they went for the much lighter weight they could achieve with external wire bracing. At their slow speed, the drag associated with the bracing was less than the drag that would have been created as a product of lifting a heavier aircraft.
Never shake hands with a man you meet in a fertility clinic.
"The goal of the NASA supersonic research program is to find aircraft designs that will significantly reduce noise, nitrogen oxide emissions, fuel burn and air traffic congestion by the year 2035."
Reduce air traffic congestion?
What? Are they solar powered and only fly on the sunny side o' Earth?
The article mentioned both air-speed decreases and fueling/loading times lowered. Both of those mean more airtime, which in turn means more planes in the air at any given time. How does that equate to "reduced air traffic congestion"?
Or, is this a more meaningful of example of "whoosh!"?
The press release is devoid of details, but a google search turns up that they're decoupling the jet engine (which generates the power) from the bypass fan (which generates most of the thrust).
For those not up to speed on jet engine technology, modern turbofans are essentially ducted propellers. The engine itself occupies a small section in the center. It burns fuel and throws the air it consumes out the back at a higher speed. This generates about 20% of the total thrust. The rest of the energy goes into spinning the bypass fan blades. Just like a propeller, they grab large chunks of air which never goes through the combustion chamber, and push it out the back at higher speed to generate about 80% of the thrust.
In current engine designs, the blades of the two are locked together (although some of the compressor blades inside the engine may rotate at a different speed). For the bypass fan blades to be spinning, the engine must also be on and spinning. The idea behind this hybrid is to decouple them so they can operate independently of each other. The bypass fan would be spun using an electric motor. I don't know the numbers involved, but theoretically that would mean you could always run the jet engine at its most efficient RPM to generate electricity, and even turn it off if there's little thrust required and the batteries have enough juice to run the bypass fan (e.g. descent).
Do the math: It is far faster, more energy efficient and easy on the environment, to fly out of the atmosphere in a suborbital trajectory, reentering near your destination. Oh, but we have to wait for NASA to develop that and they are mothballing the shuttle program so it must be a non-starter. Right?
Seastead this.
Nice to see Boeingnot relying on state funding for their research and development.
***You learn something Every day. And then you die.***
All the cool crap we'll have in 25 years! Just think of what you had gadget wise in 1985...yeah me neither, now imagine 1995...yeah still not a lot but better...then think of 2005...holy crap it got better...now think of that progression 25 years into the future and tell me it wont kick ass!