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A380 & 787: Last major tube & wing designs?

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Thought it would be interesting to see what you all thought on this matter.I feel that the A380 & 787 are the pinnacle of conventional "tube with wings sticking out" designs - at least when it comes to the two major commercial aircraft manufacturers.I think that the sucessors to these two planes (probably already on the CAD & CATIA screens of both companies) will be blended wing-body designs.http://www.twitt.org/bwb1.jpgI feel that in our lifetimes we will certainly see this next generation of airplanes take flight.The only disadvantage for us airplane nuts will be....a reduced number of windows!!!!Noooooo http://www.nextgenerationrecords.co.uk/boa...es/icon_eek.gifWhat say you all? :)

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---> What say you all? I'm with stupid ! :) lolBecause:1) ur example aircraft has exessive fuel consumption as the wing-area is too big.2) Risk. If the A380 would have or will be a failure, than Airbus is bankrupt. The A380 is a die or win project.U wanna risk everything ?3) Save of investment.The current flying-tubes are extemely successful in economics.A 3000 miles trip with an A320 is extremely cheap.Beat the seat per mile price ! Nobody cares how a plane looks like, the costs are important. $$

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>1) ur example aircraft has exessive fuel consumption as the>wing-area is too big.>I didn't know they had aircraft designs in Ur? Back then people dreamed of flying but didn't try to make machines to do it.This drawing is actually a concept study that has been in existence for several years. It won't have excessive fuel consumption at all if properly designed.>2) Risk. If the A380 would have or will be a failure, than>Airbus is bankrupt. The A380 is a die or win project.>U wanna risk everything ?>Someone called U may be willing to risk it all, aircraft manufacturers do it all the time.Boeing risked the company on the 707, again on the 747, and now on the 787.Airbus won't go bankrupt if the A380 fails, the terms of their "loans" from the EU state they don't have to pay them back if they don't want to so development is effectively free for them.>3) Save of investment.>The current flying-tubes are extemely successful in>economics.>A 3000 miles trip with an A320 is extremely cheap.>Beat the seat per mile price ! Nobody cares how a plane looks>like, the costs are important. >And that's why a different design is needed to reduce cost further. The ONLY reason manufacturers so far have all gone with the tube with wings design is because it's easy to calculate all the forces on it on paper. Different shapes were too difficult to calculate in the 1930s and ever since inertia has prevented them from being more than a fringe phenomenon.Yet the Northrop and other flying wing designs have excellent performance and fuel efficiency. If they haven't really become commonplace that's mainly because they are inherently unstable and until recently manufacturers couldn't provide control equipment to make them flyable well. The B-2 proves that now it is possible.The Boeing BWB might yet fly at some stage. But it will take time. Boeing currently has no funds to bring it from the concept stage.

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Donny AKA ShalomarFly 2 ROCKS!!!The one disadvantage I have heard about blended body/flying wing airliners is the "elevator sensation" passengers might experience when entering/exiting turns, since many of them would be seated further from the center of the roll axis.

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I totally disagree. The beauty of the current concept is the adaptability of the design to modification. Any form of flying wing will be almost impossible to easily modify. Each flying wing would have to be a completely new design from the ground up. I think the current tube and wing design will continue.The next logical step will be a stretched version of the A380. :-eek The current A380 only requires 70,000 lbs thrust out of each engine yet Rolls have the Trent already pushing out 90,000 lbs static thrust. I can't believe that Airbus Industries haven't got uping the size of the A380 burried deep in the drawing office somewhere. :-lolJust my wild thoughts; economics runs the aviation worldRoger

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------------------------------------------------------------------------The next logical step will be a stretched version of the A380------------------------------------------------------------------------Definetly :) From what I've heard they had that planned when the A380 was being developed. Im sure like the 747 this thing will be stretched, squeezed & freigthered.And mark my words - there will be an A380 bizzjet too!Personally I will be a bit surprised if after the age of the A380 & the 787 that the next passenger airliner will not be a BW design like the B2 bomber.Im not an aerospace engineer but am I right in assuming that such designs are less draggy, carry more & produce gobs of lift?http://oea.larc.nasa.gov/PAIS/bwb1.jpg:)

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That is possible.But it could be countered by changing the interior layout.Instead of having the passengers on one deck and cargo/luggage underneath, you could put passengers on two decks and cargo/luggage out to the sides. The farthest parts would hold the fuel.Given that there likely would be no windows the psychological effects of rolling would likely be less as well.

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Most of the pictures shown of future aircraft are just the fertile imaginations of artists displaying scant regard for the technical problems or economic viability of their designs.The Flying wing concept is not new. It has been around for half a century but the inherent problems of the layout will restrict it from commercial use.So long as liquid hydro-carbon fuels hold out I think the tube and wings will be the way aircraft design goes. You would be surprised at just how small the profile drag of a fuselage is. Even on something like the 747 which cruises at M 0.85 (faster than the 707 ). By just simple streamlining the drag is reduced to only 5% of the value of the flat cross-sectional area. There is no huge drag benefit to be gained. This is why speed brakes are so prevalent on aircraft. Normal drag would take ages to slow the aircraft.The blended wing/fuselage designs seen on high speed military aircraft that you mention, probably (IMHO) has more to do with AREA RULE and transonic flight than anything else.The race is on for Hydrogen powered aircraft. This change in fuel type is what I think will dictate the next major major shift in airframe design.BUT I don't think this is likely to happen in the lifetime of anyone reading this post. :-)Just my 2c worth.Roger

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Hydrogen isn't a real alternative to hydrocarbons.The energy content is a lot lower, thus it requires far larger fueltanks.Airbus and Boeing both have (or have planned) prototypes.The Airbus prototype is an aircraft based on the A310 (I think it was, might have been an A300) with a huge bulge on the fuselage effectively doubling its volume.90% of that volume is given over to fuel, leaving no room for passengers or cargo, yet the range is only a few hundred nautical miles.

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>I feel that the A380 & 787 are the pinnacle of conventional>"tube with wings sticking out" designs - at least when it>comes to the two major commercial aircraft manufacturers.I prefer the "Flying Tylenol" analogy, myself... :( :-lol(Gotta love the movie, Airplane! :()

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>Hydrogen isn't a real alternative to hydrocarbons.Hydrogen is the ONLY viable (neglecting nuclear for obvious reasons) alternative.Hydrocarbon fuels are a finite resource. >The energy content is a lot lower, thus it requires far larger>fueltanks.>Airbus and Boeing both have (or have planned) prototypes.>The Airbus prototype is an aircraft based on the A310 (I think>it was, might have been an A300) with a huge bulge on the>fuselage effectively doubling its volume.>90% of that volume is given over to fuel, leaving no room for>passengers or cargo, yet the range is only a few hundred>nautical miles.All the above is true and that is what will dictate airframe design.If the problems are insurmountable then mass air travel will cease to exist and sea travel once more reign supreme."Necessity is the mother of invention" :-)

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Two questions about hydrogen:How much energy is needed to produce hydrogen compared with the energy hydrogen generates?What is the source of the energy needed to produce hydrogen?

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>Two questions about hydrogen:>>How much energy is needed to produce hydrogen compared with>the energy hydrogen generates?>>What is the source of the energy needed to produce hydrogen?I'm no tree hugging greeny, but my basic understanding is that in the conversion of energies the basic law of conservation of energy applies. "energy cannot be created or destroyed, but may be readilly converted from one form to another"This implies that it will take more energy to produce Hydrogen than the energy the hydrogen contains. There is no such thing as 100% efficiency. I have no idea what the actual efficiency is but it is immaterial to the debate. All it will do is determine the cost.I'm not 100% sure of this but I suspect electrical energy used in electrolyis might be the way hydrogen is commercially produced. But that is just a guess. Do a search on the net.

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I've found 2 reports on life cycle costs prepared by the National Renewable Energy Laboratory, a US government agency.The first deals with the Steam Reforming Process process which converts natural gas into hydrogen and carbon dioxide - a green house gas! It shows an efficiency of 65%-75% in creating hydrogen - ie you get 65-75% of the energy in the natural gas back in the hydrogen.The second deals with wind-powered electolyis. This shows an efficiency of about 1300% - ie you get more energy back that you put in, given the wind energy is free. How many windmills would be needed to create significant amounts of hydrogen reliably?Other reports suggest a further 30% of the hydrogen energy is needed to compress or cool it ,and that losses are about 5%/day due to evaporation. To this needs to be added the energy to distribute hydrogen, and the losses in actually converting into useful energey in the eventual vehicle.It seems there are a number of questions still to be answered.

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>The first deals with the Steam Reforming Process process which>converts natural gas into hydrogen and carbon dioxide - a>green house gas! It shows an efficiency of 65%-75% in creating>hydrogen - ie you get 65-75% of the energy in the natural gas>back in the hydrogen.>And how much energy does it take to run the process? Sure you get 70% of the energy contained in the gas into the hydrogen but you need to use more energy to run the process...>The second deals with wind-powered electolyis. This shows an>efficiency of about 1300% - ie you get more energy back that>you put in, given the wind energy is free. How many windmills>would be needed to create significant amounts of hydrogen>reliably?>Completely bogus figures. The efficiency of wind turbines is incredibly poor. The energy input to build them (making the parts, transporting the assembling them) and maintain them is so high that over their lifetime they hardly break even.The efficiency mentioned is 1300% ONLY if it is assumed that the energy gained from that turbine is free and doesn't cost anything to produce which is patently untrue.Another major problem is indeed the number of windmills needed and the space they'd take up.It is estimated that in order to supply half the fuel demands of the UK you'd need to cover the entire UK and its continental shelf with windmills of the most efficient type currently available spaced 100 meters apart.>Other reports suggest a further 30% of the hydrogen energy is>needed to compress or cool it ,and that losses are about>5%/day due to evaporation. To this needs to be added the>energy to distribute hydrogen, and the losses in actually>converting into useful energey in the eventual vehicle.>Yes, more problems making hydrogen far from the "clean" fuel that it's hyped to be.Add the insurmountable problem of sheer volume and you see how uneconomical the whole thing becomes.The Airbus example is a good illustration of that.The problem isn't that the engines are so hungry that they need a lot of fuel. In fact in number of molecules needed they may even need less for the same amount of thrust.But the storage of hydrogen needs far more space and infrastructure (and thus weight) than does the storage of most other fuels.Thus it is impractical to use in any place where large volumes are needed and no access to a pipeline to a distribution network exists (such as in aircraft).Cars have the same problem, their range on hydrogen is a lot less for the same volume of fuel thus they need larger tanks and still need to be refueled more often.>It seems there are a number of questions still to be>answered.>The 1960s idea of nuclear propulsion may be the answer. Miniaturisation has made reactors smaller and shielding more efficient by now.This could allow aircraft to potentially carry their own nuclear reactors to either drive the engines directly or to extract hydrogen from thin air.

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