Flying wing: The Boeing X-48B, an unmanned prototype with a 6.4-meter wingspan, has a blended-wing design that could one day replace that of today's commercial planes.
NASA
Advanced technology won't be enough for the industry to meet its own greenhouse-gas targets.
Last week the global aviation industry called on the United Nations to establish a single, worldwide policy for reducing aviation greenhouse-gas emissions, in an attempt to avoid a costly network of regional regulations. The industry proposed two primary goals--that by 2020 it should stop increasing its greenhouse emissions, and that by 2050 it should cut its emissions by 50 percent compared to 2005 levels.
These goals, while less stringent than the 80 percent reductions proposed for the rest of the world's economy, may nevertheless prove too ambitious, some experts say. Furthermore, an array of potential technologies that could significantly reduce emissions will be difficult to deploy quickly in an industry that is reluctant to take on the cost and risk of radical innovation and that can take decades to replace old airplanes.
Whichever new technologies do get implemented may not be enough to keep up with the industry's growth. Each year the industry reduces fuel consumption by improving efficiency by 1.5 percent to 2 percent. But each year people fly more--the industry is expected to grow by 4 percent to 5 percent--overwhelming fuel savings from efficiency.
Part of the problem is that it takes the industry as long as 20 to 30 years to replace planes. This means that the efficiency improvements of planes introduced in 2010 won't be seen throughout the fleet until 2025 or later. If things continue as they have been in recent years, by 2050 the industry will have to fly "three times as many airplanes with only half as many emissions," says Ian Waitz, a professor of aeronautics and astronautics at MIT and director of the Partnership for Air Transportation Noise and Emissions Reduction. "It's a tremendous challenge," he says. The challenge is so great that climate-change policies may force a tradeoff--requirements to cut emissions may increase prices and slow the growth of the industry.
The aviation industry can limit its emissions in three basic ways--making airplanes more efficient, improving logistics to waste less fuel, and replacing fossil fuels with biofuels. But some potential technical improvements are limited because of the engineering requirements of airplanes. For example, it's conceivable that batteries and electric motors could one day replace internal combustion engines in cars. But batteries don't store enough energy to transport a commercial airliner across the Pacific.
With these limitations in mind, by 2020, new technologies could make aircraft about 20 percent to 35 percent more efficient, on average, than planes today. Fuselage coatings and adjustable wings, among other things, could reduce drag. Engines that run hotter and at higher pressures would use less fuel, as would engines that use gears to optimize the speeds of different parts of a turbine, and open-rotor designs that resemble and have some of the efficiency advantages of turboprops.
If the United States wants to build a market-based approach to reducing carbon dioxide emissions, it should learn from Europe's failures.
I think the hybrid airships being developed right now could significantly reduce fuel consumption and could be used effectively on many of the shorter routes that aeroplanes fly today.
I agree, i would love to travel this way. But in todays fast paced world everything is about speed. Those airships are slow. It would be great tho to have a slower and hopefully much greener way to travel by air as an alternative.
While flight speed is important, it is not always the critical factor. For example:
1) A direct NYC to MIA flight takes about 3.25 hours. With one stop, say in Atlanta, the trip takes almost twice as long. A direct airship flight should take less than 7 hours. For casual fliers, and even many business fliers, this would be acceptable. I know I would prefer to do some reading and work on the Internet uninterrupted on a flight rather than waste to boarding and "wandering" the airport due to a connecting flight.
2)A substantial amount of air freight could accept a few hours delay. More important, certain ground freight could support a bit of a premium for "slower" air freight. This could create a new freight category.
I agree. Airships beat fixed wing craft hands down when it comes to efficiency. The natural lift of the craft is provided by the air-bags.
The Obama administrations cracker-jack team of Inter-City High Speed Rail experts may want to rethink their plans. Airships travel "as a crow flies", up to speeds faster than ground based rail systems with out the need to build and maintain the rails themselves. In addition, you can cross open expanses water too, so trips from NY to Chicago (over the Great Lakes), or Milwalkee to Cleveland would be quick and safe. The fact you save billions on the simple Right of Way access needed for rails means those dollars could be shifted to the basic R&D and Production facilities for a new aircraft industry.
Basic airship commuter flights would be comfortable and safe, and Super-lift systems could be developed to move freight.
Not bad for something that's been around (and proven to be safe by Mythbusters) for almost a century.
Now if we can get Jimmie Page, Robert Plant, John Paul Jones and a great drummer back together again we'll have something!
What airship do you know that travels as fast as any existing fast train? Most are unfit to fly in any significant wind. All the Goodyear Zeppelins were lost in storms, one on the ground, the other two while flying. New York to Miami would normally mean crabbing into a crosswind with a resultant forward speed of probably less than 40 mph making the travel time about a day. Modern blimps don't fly in wind above 15 mph.
Would be airship makers, always seeking funding, make wild claims written as if they actually have airships, but never build one, let alone prove their performance. There are very good reasons why the skies are not filled with these relics.
While the use of airships is initially attractive, especially for cargo operations I suggest that airships and severe weather do not mix very well. While it may be possible to operate in clear weather on a nice summer day, operations in winter where snow and icing are considerations may prove impracticable. Summer thunder storms can be violet to all flight operations and are generally avoided where possible with air traffic control redirecting traffic. The time it takes for a large, lumbering air ship to circumnavigate an extended line of weather could double the normal trip time.
Couldn't airline companies and plane manufacturers get involved more in designing and manufacturing wind turbines and then paying for them directly to be installed. No need to fuss around with carbon trading.
The gram-years of jet exhaust at 30,000' is something like 10X that of jet exhaust at 10,000 feet. Yes, flying lower does increase the number of grams of pollution by about 30%, but flying lower greatly decreases the number of years it stays in the atmosphere.
- - - Learned while working at Boeing
Re: 10X reduction by flying lower
As far as light craft are concerned, Leik Myrabo has some really interesting ideas and research in that area. I suggest anyone interested in truly innovative solutions read his book, Lightcraft.
Gary 7
Some investigation last year determined that US airlines use 10% of all fuel used for transportation to benefit 1% of the population. Never was able to determine how much more polluting they are but their engines are certainly contributing much more than our highly regulated car engines which emit about 1000 times less pollution than unregulated engines pre 1967.
How about drastically reducing flying?
Rewind about 100+ years to the era when men though only birds could fly. The dogma has now drastically changed and any human can now board a huge aluminum can and fly at the expense of enormous amounts of jet fuel. Ask yourself if such expense is justifiable or sustainable? Compare the energetics of traveling by water, land and air and the answer will be that humans can't fly, not without overheating their planet.
This conclusion is devastating to the airline industry but should we really sacrifice the planet so that they can meet their growth projections? How about branching out into other forms of transportation like bullet-trains. For me, door-to-door going through SFO and LAX end up taking about as long as driving to LA from SF event though the actual flight is only about 1:30 hrs, the overhead of airports and security, etc... makes flying only reasonable for long distance trips. With a proper train network flying can be significantly reduced without compromising consumer "needs".
Re: How about drastically reducing flying?
The solution to atmospheric pollution from aircraft is staring us in the face - literally. It's the computer you're reading this on.
I have flown on business exactly once in the last decade. However, I teleconference several times a day. Not only does this save time and money, it is far more effective in actually getting work done.
For pleasure travel, take your electric car. Convert airplanes to something useful - like beer cans.
Re: How about drastically reducing flying?
Come on. Teleconferencing is not the solution. There is a huge tourist industry out there that depends on air travel. It would be a much bigger industry if air travel was cheap, fast and efficient. And I will not even go into the air cargo industry. We need cheap ways to ship goods and people as fast and as far as possible.
Re: How about drastically reducing flying?
When talking about saving the planet, the tourist industry gets a very, very low priority.
To the engineer, the subject isn't eliminating air travel, just drastically reducing it. Getting rid of the 80%+ of seats filled by tourists and 'business' travelers on non-essential trips would do that.
The problem is that aviation just can't be cleaned up. Even if 100% biofuel was used, it still transports CO2 to the stratosphere where it stays for a very long time. That's unsustainable.
Bill D
Aerospace engineer and commercial pilot
Re: How about drastically reducing flying?
<i>The problem is that aviation just can't be cleaned up.</i>
That's because everybody is thinking inside the box.
Your industry only requires a voice or data, so telecommuting or email works fine. Mine requires that I or another engineer physically be on location and interact with the issue at hand.
Guest (reb)
With such an extremely difficult problem one needs to "think different". Air traffic reduction is the only possible method to achieve the goals. Combine new, high speed monorail electric trains with smart grid distribution lines instead of crowding the skies further. Add fast product distribution to it's use and reduce the overnight delivery air fleets. The costs could be amortized over a much longer lifespan of a low environmental impact.
Absolutely. Electrified rail is the minimum polluter on a ton mile or passenger miles basis. Europe has proven this.
However, fixed right-of-way systems go from A to B and nobody lives at point A or wants to go to point B.
So, thinking outside the box...
Why not expand transport of personal electric vehicles by passenger rail. Drive to the train station, park your electric car or motorcycle on a special rail car and enjoy the trip from inside the train. On arrival, drive your own car to your real destination. That way there's no electric car "range anxiety".
Conceptually wonderful, however, it takes at least 2 times longer (actually more like 3 to 5+ times) to do a train trip versus air. More important, it is much more expensive. Compare the fares for the "Autotrain" from DC to Orlando.
Can hydrogen be used for fuel for aviation. Just water vapor as exhaust. Water vapor would be easier to cleanup.
Hydrogen could be used, but it really needs to be liquid hydrogen for the highest density. That requires better insulation technology. Think vacuum container (dewar flask) type fuel tanks probably constructed out of carbon nanotube fabric (strong, lightweight). Indeed if you could construct the entire "plane" / "airship" out of CNT you could have a lot more flexibility with respect to travel speed, amount of pollution, etc. Hydrogen isn't going to work for classical planes until they solve the storage problem for automobiles.
Let's keep our feet on the ground
Gentlemen,
I believe we must go back to basics on this discussion. Let's pave a common ground from which we may all post our comments:
1) Aviation industry's top-concern is fuel burn reduction. And there's nothing to do with environmental concerns here: 20% to 30% of an airline's operational cost is fuel cost. It's an economic issue here, and aviation industry has already done a big effort in the last 50 years: modern aircraft burn around 70% less fuel per ASM then 1955 models.
2) Aviation industry's top-concern keeps beeing fuel burn reduction: 787 is marketed heavily on fuel reduction. Bombardier C-Series is not taking off mainly due to not being able to prove fuel burn reduction claims made by the manufacturer. Again, economic perspective is the driver.
3) Aviation accounts for 1.5% of all carbon emissions in the world. Yes, just one point five percent. This is data from a 2006 European Comission study regarding fuel burn from all sources. Road vehicles, for instance accounts for 52,8%.
Regards,
Meneghelo
True, aviation currently contributes only 1.5% of the worlds CO2 - but it leaves it in the STRATOSPHERE where it stays for 100's of years. Most surface CO2 gets recycled into plants and rocks in much less time. Worse, aviation leaves H2O vapor in the stratosphere significantly increasing cloudiness which holds in heat.
This isn't theory, atmospheric scientists got solid data when aviation was shut down for three days after 9/11. Some estimates have aviation as the cause of 30% of global warming.
Fuel burn reduction is a good thing but the gains will be small. Most of the "low hanging fruit" has already been picked in that area. The best route is to go big. Both turbine engines and airframes get more efficient as they get bigger.
Thinking very much outside the box
You need to think along multiple lines here. A recent PNAS article pointed out that the U.S. has 14x its current electric consumption available as renewable wind power (all it takes is the turbines and transmission lines). Once constructed those costs are largely sunk costs (so electricity cost per kWH should trend towards zero). If you have very cheap electricity you move from traditional tunnel "boring" to tunnel cutting (e.g. automated robotic plasma torches). Put superconducting electric transmission cables as well as bullet trains in the same tunnels so you can get cheap renewable electricity and low cost fast city-to-city transportation. (All of this is off-the-shelf technology that simply requires funding).
For "green" (renewable) air transport fuel, you want "biofuels" (existing technology) plus enzymatic or advanced chemical conversion to the cleanest chemical fuel. Change current "messy" fuel "mixes" to a single hydrocarbon (e.g. nonane, octane, etc.) so that the engines can be optimized for minimal pollution. Ultimately propane or LNG might be the least polluting choice. It is worth noting that current biofuels aren't even close to the limits. Plants currently convert solar energy at 2-4% efficiency. Advanced photobioreactors (which is what cyanobacteria or algae ponds could approach) is more in the 10-15% range.
For "green" (non-atmosphere polluting) fuel you may need to switch to hydrogen and that requires a totally new aircraft infrastructure (see earlier post). If you really want to stay out of the air entirely and have the fastest travel times you are going to need evacuated sub-sea-surface tunnels with Maglev trains. Those could be considered "near term" technologies simply requiring some engineering and funding.
Now it is interesting that since many of the "barriers" here are investment funding (not engineering) and that if really "pushed" the technologies and investments should result in infrastructures that tend to drive costs (and profits) towards zero the real problem is capitalist economies. Very few "organizations" (corporations / governments / etc.) operate in ways designed to drive themselves out of business.
With the advancement of today's engines and aerodynamics, we should see more efficient planes soon. But again, it will take a long time before we can be fully upgraded. That is the major con about industry, it takes forever before a new thing comes in. But we should all be fine by 2020, when we fully replace all the old planes with the new advanced planes.
Manufacturing in the United States is in trouble. That's bad news not just for the country's economy but for the future of innovation.
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Mapou
357 Comments
How Aviation Can Come Clean? Hum. Let Me Count the Ways
Right up my alley, thank you. There is only one way that the aviation industry can come squeaky-clean (no emission whatsoever) and that is to abandon the erroneous paradigms and primitive chemistry-based propulsion technologies of the baby boomer century and forge a bold new future. How can it do that? What else is there besides the same old stuff? Well, there is the realization that we are literally swimming in energy, lots and lots of clean energy. A recent reevaluation of our understanding of the causality of motion leads to the inescapable conclusion that we are immersed in an immense lattice of energetic particles. This huge energy field can be tapped into for both super fast propulsion and energy production. Soon, we’ll have vehicles that can travel almost anywhere at enormous speeds and negotiate right angle turns without slowing down and without incurring any damage due to inertial effects. Floating cities, earth to Mars in hours, New York to Beijing in minutes… That is the future of energy and travel.
My advice to aviation is this. Soon, there will be very little distinction between ground, air and space transportation. It will all be based on the same advanced technology. You would do well to carefully examine the writing on the wall from all angles and prepare yourselves for radical change ahead.
You don’t understand motion, even if you think you do:
http://rebelscience.blogspot.com/2009/09/physics-problem-with-motion-part-i.html
Reply
nishant kumar
12 Comments
Re: How Aviation Can Come Clean? Hum. Let Me Count the Ways
Wow!
You should be a science fiction movie director, with that dazzling imagination of yours.
Yet, your comment seems to be slightly incongruous. Please forget the fantasy, and live in reality. It must be acknowledged and accepted, rather than diverting from the main issue, that global warming is a real problem, and the aviation industry is a huge contributor to this problem. I think this article adresses some important issues, whilst injforming us about the changes that are hopefully about to take place in the aviation industry. The message is simple yet powerful, if there is a joint effort to improve the energy efficiency of the aviation industry, then the entire world will substantially benefit from it. As far as I am concerned, I believe that the aviation industry must be taken seriously, since I don't see any evidence or signs of your imaginary prediction in the coming future. No flying cities, or high-speed transportation systems.Neither, do I believe that the aviation industry is ever going to disappear. As the article suggests, biofuels is an optimistic prospect for the aviation industry, and the demand is growing 4percent anualy. The aviation industry needs to act today, rather than tomorrow to make a difference in carbon emmisions. Biofuels is an excellent way of transforming before oil peaks and global temperatures rise.
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Mapou
357 Comments
Re: How Aviation Can Come Clean? Hum. Let Me Count the Ways
Wow!
'Wow!' does not come close to doing it justice.
You should be a science fiction movie director, with that dazzling imagination of yours.
Maybe. But I prefer reality because it's stranger than fiction.
Reply
ranadrew
31 Comments
Re: How Aviation Can Come Clean? Hum. Let Me Count the Ways
I want some of what he's smokin'!
Reply
Mapou
357 Comments
Re: How Aviation Can Come Clean? Hum. Let Me Count the Ways
You do, indeed.
Reply