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Airplanes use enormous amounts of fossil fuel. After Peak Oil fuel costs will keep rising. When we become unable to afford this anymore, we'll have to find an alternative.
Energy needed to keep an airplane moving at high speed is to overcome friction or air resistance. Lower the speed and you'll
have much much lower fuel consumption.
I propose giant airplanes that are gliders with very small engines that travel around 60 mph. Two designs come to mind:
1. looks like a giant glider, with a prop and small engine.
I don't know if it is possible to make very large wings that are strong enough. This might be a problem, so design #2:
2. a vast mesh of gliders, all connected to each other, either at the wingtips or tailfin to wingtip. Propellor engines are placed where useful.
These airplanes should be able to carry at least a 100 people and travel at about 60 mph. Imagine, you could travel from New York to LA in 40 hours!
Obviously this wouldn't be so handy on routes that have good railway or ship lines, but perhaps good for travel across areas that have both land and water.
NY to LA via car
http://maps.google....1384,82.441406&om=1
a hop and a skip... [MoreCowbell, Jul 06 2006]
Glider_20transport_20system
[xaviergisz, Jul 06 2006]
tic-tac-toe plane
http://scaled.com/p...ical_transport_attt
not a motoglider though. [FlyingToaster, Jul 12 2012]
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I like the leap of logic to " at least a 100 people and travel at about 60 mph ". No math required. |
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But it certainly would be nice to travel without all that subsonic roaring in my ears. |
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...the restroom is up in the third glider, just walk across these tailfins.... |
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Sounds liked a fully baked airship. Oh, the humanity! Must remember not to paint the dirigible skin with rocket fuel this time. |
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but [strange], the racing stripes don't work
if they're made out of normal paint. |
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This is not an airship or blimp. It's a very large airplane that has the wings to fly at low speed. It will have enormous wingspan. Similar in design to a glider, but powered. |
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If regular shaped wings of that size are a problem (I don't know if they are and I don't even know how to design this) we need an alternative design. The mesh is just one idea to overcome this possible problem. A biplane (or triplane etc.) glider design would be another option. |
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Unlike a blimp, such an airplane does not require the containment of large amounts of hydrogen or helium and it should be able to attain higher speeds. |
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[jmvw], wings have to be able to push air.
mesh wings won't cut it. you could use a
fabric covering though. i'd pay for a ticket
across the country in a biplane or even
triplane. |
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Why would you want to send a ticket across the country in an airplane? Wouldn't it be easier to just mail it? |
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but that's not recursive enough for me
[jmnw] |
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//Sounds liked a fully baked airship. // Airships rock! If the Hindy (not attempting to spell it) handn't gone down in flames, dirigibles would probably still be used today for travel. I wish they would make a comeback. Trains are good for scenic travel but a blimp would give a nice view. |
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[return to topic] According to Google you can drive from NY to LA in 46 hours (see link). If you pay $3.00 a gallon for gas it would cost $344 in fuel (assuming average of 25 mpg). Depending on how long you drive each day and how many people are travelling, food costs would vary. In the end I think this is less expensive than developing a new method travel that doesn't save much time in the end. |
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Jet aircraft travel fast because they fly at high altitudes where air pressure (and hence air resistance) is low. The speed and altitude of airplanes is chosen for optimal efficiency. |
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I think road transport is a better target for increasing travel efficiency (see shamelessly self-promoting link) |
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After a while though, you just have to quit stalling. |
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A litle googling showed that 60 mph is airship speed and that speed record for gliders is 166 km/h, about 100 mph. |
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xaviergisz: are you saying that the speed of airliners has not been set by the desire to go fast, but by optimum fuel efficiency to cover a certain distance? |
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[jmvw], I meant economic efficiency which includes fuel efficency as well as other factors such as speed, passenger capacity etc. |
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Damn, [MoreCowbell], it takes longer for that link to load than it would to drive that distance. |
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[+] an underappreciated post. I doubt the mesh thing would work and it'd be pretty pointless, but a biplane might be feasible (extra tip drag and vortices but you'd still get more wing out of the deal). No idea how big you can make a motoglider. |
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This was mentioned in an episode of e². It was
claimed (and it seems reasonable to me) that
reducing speed would create a disproportionately
large reduction in fuel consumption. In other
words, this is a good idea, even if not taken to
such an extreme. |
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It should be sold on price. You should be able to
choose to travel at (say) Ÿ the speed for
somewhat less than Ÿ the price. If it isn't cheaper
then it probably doesn't represent an overall
energy saving, simply because of the way the
economy works. |
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I think [tcarson] misunderstood the mesh thing.
It's a mesh made up of many connected gliders,
not a glider with wings made of mesh. The
objection still holds, though. The extra structure
(and associated mass) required to hold multiple
gliders in fixed relation to each other would be
better spent on longer wings, or just bigger
(unconnected) gliders. |
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A triplane having wing dimensions similar to a regular sailplane could probably carry 3-4 people in tandem in a slightly elongated fuselage. Given the very low chord there wouldn't be any interference between the wings but motor power would have to be increased. |
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A mesh wouldn't work depthwise (ie: you couldn't have too many wings or structures behind each other) but side-to-side, say with the motors each mounted in the middle of a wing between fuselages: with central, computer-assisted control of all flight surfaces and engines... that would only be limited by the strength of wind-shears and the width of thermals and downdrafts. |
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I would guess, though, that if you melted down the
triplane and made it into either (a) three small
monoplanes or (b) one big monoplane you would get
an increase in performance, by almost any measure. |
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The only benefits I'm aware of of multiple wings are
the structural efficiency of vertically stacked wings
acting as a truss, and greater lift per wingspan. For
fuel efficiency, four wings good, two wings (slightly)
better. |
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The bi/triplane bit is reactionary to watching gliders' wings flex: obviously there's a limit to how much of a span you can put on those things. |
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High-aspect wings should be better biplane wings regarding lift efficiency as far as I can tell: the tip vortices are less, and the wings' airflows won't interfere with each other (as much as on a lower AR biplane). |
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[edit: so you'd think I'd be able to find one on the 'net wouldn't you, oh well. There were plenty of biplane gliders that looked like WWI vintage aircraft without engines, but no modern 'glass biplane sailplanes at all, save one model which had the tips joined together] |
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