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MIT Designs Aircraft That Uses 70% Less Fuel Than Conventional Planes
greenrainbow writes "Today a team of researchers at MIT unveiled their design for an airplane that uses 70% less fuel than conventional aircraft. The MIT design comes thanks to a NASA-funded initiative to increase fuel efficiency, lower emissions, and allow planes to take off on shorter runways. The team accomplished all of NASA's set goals with their innovative D-series plane, lovingly referred to as the 'double bubble,' which has thinner, longer wings and a smaller tail, and engine placement at the rear of the plane instead of on the wings."
Having a viable prototype design that's gone through simulations and the like is a lot more than artists renderings. What the hell do you think they do to make an airplane? Take some steel, rivets, and aluminum out to the hangar and just see where things end up?
"People who think they know everything are very annoying to those of us who do."-Mark Twain
There is no scale provided so you wonder what they are calculating on, is it fuel per mile per passenger? Anything else would be irrelevant.
The two designs carry the exact same number of passengers as the planes they are hypothetically replacing, the 180-passenger 737 and 350-passenger 777, so there's no difference in this case between miles per gallon and passenger-miles per gallon. :)
The enemies of Democracy are
While I'm sure you can devise a design which, as part of greater fuel economy, flies slower (turboprops might be just that...) - it won't really work for existing aircraft, like mentioned by you 737s. Airlines take care to fly them at optimal speed, not the greatest speed; optimal for fuel economy.
For example Rynair (which cares greatly about lowering costs...), some time ago, changed the guidalines for cruising speed by...2 or 3 km/h. Accidentally in this case it was lowering it, but might have been just as well an increase; what works best for given airplane / engines / routes / weight combo (didn't stop local journalists from proclaiming "Ryanair will fly slower to save fuel", which was technically correct, but....)
One that hath name thou can not otter
One way they save fuel: flying slower than current aircraft.
No. While they do fly slightly (10%) slower than existing aircraft, they do that to mitigate engine stress.
will customers accept that?
Well, they seem to "accept" waiting 2-3 hours in security lines, so I'm guesing yes.
why not just fly current 737s a bit slower right now, to save on fuel?
You honestly believe that flying a 737 10% slower will reduce fuel consumption by 50%? I can tell you that if an airline reduce their costs anywhere close to that much, they'd do it in a heartbeat.
According to the article the proposed 737 replacement has standard wing length and is suitable for existing airports.
The type D is specifically designed to work with existing airports without drastically changing the terminals.
The type H, however, would require changes to current airports. The article says that these designs are planed for a 2035 deployment, though, so plenty of time to make the requisite changes, if the airlines so chose.
The FAA has prohibited overland supersonic flight except for explicitly-approved military flights for decades now. Even the military has to get permission when outside of established supersonic corridors, most of which are controlled by the FAA. (Many people are often amazed at how much authority the FAA has over military flights within US borders.)
NASA has conducted a great deal of research into quieting sonic booms, either by deflecting them upward or by canceling them out. I imagine those will be or have been factored into MIT's proposals.
You can never go home again... but I guess you can shop there.
Not exponentially! No! Something that is rising exponentially is rising as 2^x, which is like hitting a brick wall compared to something rising quadratically, which, if your math is right, is how fuel costs would rise with increasing speed. And your math seems right.
Disclaimer: IANAL. This post is, however, legal advice, and creates an attorney-client relationship.