coondoggie writes to mention that NASA's Green Flight Challenge is offering up to $1.5 million for an aircraft that can hit 200 passenger miles per gallon while maintaining 100 mph on a 200 mile flight. "The Challenge is intended to bring about the development and convergence of new technologies and innovations that can improve the community acceptance, efficiency, door-to-door speed, utility, environmental-friendliness, affordability and safety of future air vehicles, CAFÉ stated. Such technologies and innovations include, but are not limited to, bio-fueled propulsion, breakthroughs in batteries, motors, fuel-cells and ultra-capacitors that enable electric-powered flight, advanced high lift technologies for very short takeoff and landing distances, ultra-quiet propellers, enhanced structural efficiency by advances in material science and nano-technology and safety features such as vehicle parachutes and air-bags."
I was seeing sports cars advertised at 100 MPG at 100 MPH back in 1995. There were several listed in the Brands Hatch F1 program, as I recall. (Anyone who still has a copy like to verify that?)
The current record for fuel economy at regular road speeds in a car is something like 6000 MPG. The current record for fuel economy in any petrol-driven engine without assistance from alternative sources is 9998 MPG.
Aircraft have an advantage in that they have no ground friction to deal with. Also, prop planes have be
That image had me laughing out loud. The [nasa.gov] link tag clinches it.
Anyway, "200mpg" doesn't necessarily mean it can do the whole journey in one gallon of fuel. Maybe you can spend a bunch of fuel to get it up to speed and altitude, then glide 200 miles on just a gallon. Gliders can travel thousands of miles on no power at all, although they don't carry passengers.
Yes, that was my point. Lift offsets gravity. But lift causes drag, which requires thrust to offset. Thrust is produced by the engines, which requires... energy!
Hence my comment, "they have to use additional energy to offset that little force called gravity".
Yes you can, and it's called a honda or a subaru or any small car that seats 4. These are passenger miles, not MPG. Hell, my piggish WRX gets 26 mpg on a long trip, so that's 104 passenger MPG if I have 3 people with me.
It's not miles per gallon it's passenger miles per gallon. That means a car carrying 5 people would have to get 40 miles per gallon. That's by no means unachievable. It's quite high for an aircraft though. I think the A380 gets under 50 passenger miles per gallon.
because aircraft can change their point to point routes only limited by rules put on their flight. To replicate that with trains would be pretty much outside the realm of feasibility.
Lets propose we could actually build such a network, it would most likely be a hub and spoke arrangement. This means that what is a direct route for a plane would be a minimum of two stops for a train. The reason flight is so popular is because of its preservation of time which to many is the most important resource they hav
because aircraft can change their point to point routes only limited by rules put on their flight. To replicate that with trains would be pretty much outside the realm of feasibility.
Not true. Trains may be confined to going wherever there are rails, but planes are limited to going wherever there are airports big enough to land.
Proper high-speed trains are almost as fast for regional transportation and far cheaper.
Lets propose we could actually build such a network, it would most likely be a hub and spoke arrangement.
Yeah, thank god noone in the airline industry ever heard of the term "hub and spoke". Can you imagine, hours of layovers or racing from one end of a mega terminal to the other because you have to get a "connecting flight". Not to mention the endless possibilities for the airline to lose your luggage.
Thankfully, all that remains firmly in the realm of fantasy.
Why not? Schools and Universities generally did better at the Micromouse tournament than "professional" engineers. Generally, it was the same class of people you saw winning Eggmobile contests. Boeing didn't win the X-Prize, and I don't believe it was any of the super-giant aviation companies that did the work on the two round-the-world record flights.
Hell, although big companies have contributed to Bloodhound (the 1000 MPH car being built in the UK), it is largely driven by super-genius inventors and engineers in a small team.
For that matter, look at who is doing well in Formula 1. Braun. A small bunch of enthusiasts who told Honda where their management could go. Look at who is quitting. BMW. The super-giants aren't guaranteed to walk off with the big prizes just because they're big companies. It happens, sure, but it's not in itself a recipe for success.
This is a prize, not a cost-plus contract. Boeing and Northrop and LockMart are free to enter, but they're looking for innovative designs on what can be a fairly small aircraft. Therefore small teams from those companies are likely to be on equal footing with smaller companies and university teams. One group I'm familiar with that could make a good showing is a small company thats based out of Stanford working on 2-man electric aircraft.
Compare it to the NASA COTS contract, where the Lockheed/Boeing grou
I think this may not be aimed at the 747 market. There is a fair push for small, light planes, which only carry a few passengers, and can be flown weekends by a person with an average income. This is probably going to be something a bit bigger than that, but it's easy to think regional-to-regional airports. There are a lot more of them there are airports that can handle a 747, and if you could make a plane that could fly from/to those cheaply it would be well worth it.
The Airbus A-380 gets roughly 100 passenger-miles per gallon, cruising substantially faster and further. Surely with only enough fuel for a short 100 mile flight, no cargo, you could cram twice as many people in it, and easily get your 200 passenger-miles per gallon. Of course, chartering one, might cost more than the prize is worth...
I wonder if there are limits on the sizes of the passengers? I mean seriously winning this prize with little people would be way easier than the same number of 6' tall obese people. Though telling NASA "the key is to only transport little people" might not make them too happy.
I wonder if there are limits on the sizes of the passengers?
The FAA has determined that the "average" passenger weighs 170 lbs for the purposes of advertising how many "passengers" a plane can carry. Thus, a Cessna 172, with 4 seats, but with a fully fueled capacity of about 650 pounds. is a "3 passenger plane" when fully fueled. You can, of course, decide not to fill your tanks all the way, or you fly overloaded.
I agree with another poster, however... 1.5 million dollars is hardly worth getting out of bed
I'm going to guess, however, that if it actually IS done, that it will be some variation of a Rutan Long-EZ, since they are widely known/touted as "the plane" for high-efficiency experimental-class aircraft.
Wikipedia says that a Long-EZ will do 1600 miles on 52 gallons of fuel. That's 61.5 passenger miles per gallon. It also typically cruises at 184mph - parasitic drag will be 3.39 times less at 100mph, but induced drag will be 3.39 times greater. I am unable to find a chart of both for a Long-EZ (here is a generic one [aviation-history.com]), but 100mph probably isn't that far off from the minimum drag speed.
I suspect it'll be some variation of a motorglider - probably one that seats at least two. They have much higher aspect ratio wings, much lower sink rates, and would probably have much lower drag at 100mph.
The Voyager around-the-world aircraft (another Rutan creation) did only 41 passenger miles per gallon (averaged across the entire flight), but they were hauling 9000 lbs of fuel towards the start (53 passengers worth). I suspect it could win the challenge right now - but it'd make a lot more sense to build a different one than to unhook it from the Smithsonian ceiling.
Sorry, I just read about the hangar requirements (among other things, a max wingspan of 44 feet). This obviously disqualifies Voyager and many other motorgliders. Probably the winner (as scored by their 1/((1/mph) + (2/Passenger-MPGe)) formula) will look like a cross between the two types of planes.
Depends how quick you are, how hot they are, and how long the flight. You'd pretty much have to get started right after take....oh, I see. Um, disregard.
Sadly, an Airbus A-380 isn't going to fit in the size requirements. The plane has to fit into CAFE's hanger. Here's the floor plan [imageshack.us].
The requirements in the rules [cafefoundation.org], Appendix B, are:
Vehicle height: less than or equal to 13 feet
Vehicle length: less than or equal to 23 feet from main landing gear to tip of tail
Landing gear footprint must fit onto CAFE Scales (See CFTC floor plan, below)
Gross weight: less than or equal to 6500 pounds on main landing gear and less than or equal to 2000 lb on nose or tail wheel
Wingspan (as projected onto a level surface), if less than or equal to 44 feet, must be capable of being
shortened to less than or equal to 44 feet by wing-folding or tip removal that can be easily accomplished in
20 minutes or less by no more than 4 adult persons of average size and strength. This
is necessary to fit typical tie-downs, hangar rows and the width of the CAFE Flight Test
Center's hangar. Any small additional projected span of winglets, tip tanks or other wing
tip device, as vertically projected onto a level surface, will be included as wingspan.
Moving four passengers the 200 miles at 100 MPH on four gallons of gas would pull it off. That would be a 'raw' MPG of 50 MPG. Or, in airplane parliance, that two hour trip would consume at an average rate of 2 gph (Gallons per Hour, the normal measurement used in the aviation industry.) A two-place airplane would need to consume half as much fuel to qualify.
A Cessna 172, with four passengers, consumes somewhere between 7-10 gallons per hour. So this would be a serious improvement. There are some 'light sport' aircraft that draw near 4 GPH, but those are two-place.
Either way, still way better than requiring a raw 200 miles per gallon.
It was a sailplane. Behind the pilot it had a pusher propeller on a pod with folding props. You could sail all day, just starting the engine when the updrafts were bad and you needed to gain altitude again.
I think the article was titled something like "Fly all day on a gallon of gas."
Motorgliders have been around longer than that, but they are just as much "sporting goods" as a pure sailplane is. The auxiliary engine doesn't give you the freedom to travel long distances at will. It does two things: it saves you the $30-$60 it costs to get airborne behind a towplane, and it means that if you run out of thermals you can make it to an airport instead of landing in a farm field and calling someone to bring the trailer. If the weather isn't soarable, you aren't taking any trips.
Seriously, use it to stimulate PRIVATE innovation and investment, instead of trying to manually command-and-control the economy. The government can't do, or direct people to do, things with half the efficiency that entrepreneurs can.
plane weighs roughly 4 times as much as the passengers (proabbly lowball)
passenger weighs 80 kg
speed=100 miph=160 kph=50 m/s
so constant power required=1/50*(4*80)*10*50=3200W
Best engine efficiency ~40%, best prop ~80%, calorific content of fuel is 38 MJ/kg=.8*4*38 MJ/gallon, so fuel consumption is 3200/(.32*3.2*38*10^6) gallons per second. So in 2 hours there are 7200 seconds, so ttoal fuel used is 3200/(.32*3.2*38*10^6)*7200
So, that is 0.6 gallons for 200 miles for one passenger
Conclusion, probably do-able, it'll cost way more than 1.5 million
This; http://machinedesign.com/article/throw-out-the-textbooks-diesel-airplanes-are-here-0619 [machinedesign.com] is a production airplane already getting 133 passenger miles per gallon
per the contest conditions. its a 4 seater in current configuration but has a 950 lb load rating with full fuel. so if we assume 170 lbs per passenger 6 passengers
would put you 70 lbs over max. lose 10 gallons of fuel and your back to overall weight. this would give you 200 passenger MPG of course two would have to ride in the luggage bay
but you would still be within the planes limits. feel free to correct me if my math is off but if not and you decide to go do it and win, well 10 grand as a finders fee would be nice!!!
I agree that the NASA administration has had problems, but what's your problem with this competition? If someone wins the competition, I'd say that's 1.5 million *very* well spent. Especially compared to NASA's overall budget.
Also- a lot of NASA's problems are due to how its budget is handled by congress. Space development is a thing of long term projects to make serious headway- but that's exactly what they never have the luxury of, since the budget fluctuates enormously.
Wow (Score:5, Insightful)
I guess really I can, if I load three other people into the car, it's not too hard. Nevermind.
Re: (Score:3, Informative)
I was seeing sports cars advertised at 100 MPG at 100 MPH back in 1995. There were several listed in the Brands Hatch F1 program, as I recall. (Anyone who still has a copy like to verify that?)
The current record for fuel economy at regular road speeds in a car is something like 6000 MPG. The current record for fuel economy in any petrol-driven engine without assistance from alternative sources is 9998 MPG.
Aircraft have an advantage in that they have no ground friction to deal with. Also, prop planes have be
Re: (Score:2)
Aircraft have an advantage in that they have no ground friction to deal with.
Yeah, but they have to use additional energy to offset that little force called gravity ;)
Re: (Score:2)
Lift. [nasa.gov]
Re: (Score:2)
Anyway, "200mpg" doesn't necessarily mean it can do the whole journey in one gallon of fuel. Maybe you can spend a bunch of fuel to get it up to speed and altitude, then glide 200 miles on just a gallon. Gliders can travel thousands of miles on no power at all, although they don't carry passengers.
Re: (Score:3, Informative)
Yes, that was my point. Lift offsets gravity. But lift causes drag, which requires thrust to offset. Thrust is produced by the engines, which requires... energy!
Hence my comment, "they have to use additional energy to offset that little force called gravity".
Re:Wow (Score:4, Informative)
Parent
Re: (Score:2)
It is called high speed train (Score:3, Interesting)
Re:It is called high speed train (Score:5, Funny)
When your train flies.
Parent
Re:It is called high speed train (Score:4, Insightful)
Parent
Re: (Score:2)
and now for a maglev that uses the earth's magnetic field, rather than a (mostly) fixed-path track.
Re: (Score:2)
Trains lack flexibility (Score:3, Informative)
because aircraft can change their point to point routes only limited by rules put on their flight. To replicate that with trains would be pretty much outside the realm of feasibility.
Lets propose we could actually build such a network, it would most likely be a hub and spoke arrangement. This means that what is a direct route for a plane would be a minimum of two stops for a train. The reason flight is so popular is because of its preservation of time which to many is the most important resource they hav
Re: (Score:2)
because aircraft can change their point to point routes only limited by rules put on their flight. To replicate that with trains would be pretty much outside the realm of feasibility.
Not true. Trains may be confined to going wherever there are rails, but planes are limited to going wherever there are airports big enough to land.
Proper high-speed trains are almost as fast for regional transportation and far cheaper.
Re:Trains lack flexibility (Score:4, Funny)
Yeah, thank god noone in the airline industry ever heard of the term "hub and spoke". Can you imagine, hours of layovers or racing from one end of a mega terminal to the other because you have to get a "connecting flight". Not to mention the endless possibilities for the airline to lose your luggage.
Thankfully, all that remains firmly in the realm of fantasy.
Parent
$1.5M? Peanuts. (Score:4, Insightful)
NASA seems to have forgotten how much aircraft cost.
Re:$1.5M? Peanuts. (Score:5, Informative)
Parent
Re: (Score:2)
Yeah, leave the professionals out of this.
Re:$1.5M? Peanuts. (Score:4, Insightful)
Why not? Schools and Universities generally did better at the Micromouse tournament than "professional" engineers. Generally, it was the same class of people you saw winning Eggmobile contests. Boeing didn't win the X-Prize, and I don't believe it was any of the super-giant aviation companies that did the work on the two round-the-world record flights.
Hell, although big companies have contributed to Bloodhound (the 1000 MPH car being built in the UK), it is largely driven by super-genius inventors and engineers in a small team.
For that matter, look at who is doing well in Formula 1. Braun. A small bunch of enthusiasts who told Honda where their management could go. Look at who is quitting. BMW. The super-giants aren't guaranteed to walk off with the big prizes just because they're big companies. It happens, sure, but it's not in itself a recipe for success.
Parent
Re: (Score:2)
ummm....you forgot Lockheed Martin???
Re: (Score:2)
This is a prize, not a cost-plus contract. Boeing and Northrop and LockMart are free to enter, but they're looking for innovative designs on what can be a fairly small aircraft. Therefore small teams from those companies are likely to be on equal footing with smaller companies and university teams. One group I'm familiar with that could make a good showing is a small company thats based out of Stanford working on 2-man electric aircraft.
Compare it to the NASA COTS contract, where the Lockheed/Boeing grou
Re: (Score:2)
I think this may not be aimed at the 747 market. There is a fair push for small, light planes, which only carry a few passengers, and can be flown weekends by a person with an average income. This is probably going to be something a bit bigger than that, but it's easy to think regional-to-regional airports. There are a lot more of them there are airports that can handle a 747, and if you could make a plane that could fly from/to those cheaply it would be well worth it.
That's it? A measley 1.5 M? (Score:4, Insightful)
I mean, the aircraft itself might be worth more than that off a production line once it's been invented.
That's like offering someone $1000 for the process of turning lead into gold. I don't know that anyone would take such a low amount seriously.
Re: (Score:2)
NASA doesn't get the aircraft. You keep it, along with the patents.
A-380 halfway there (Score:5, Interesting)
Re:A-380 halfway there (Score:4, Interesting)
I wonder if there are limits on the sizes of the passengers? I mean seriously winning this prize with little people would be way easier than the same number of 6' tall obese people. Though telling NASA "the key is to only transport little people" might not make them too happy.
Parent
Re:A-380 halfway there (Score:4, Funny)
Wait I just realized, if you are allowed to use passengers as fuel using obese people might be better after all.
Parent
Re: (Score:2)
Re: (Score:2)
What if I turn them into fuel right before landing? Though landing with more fuel than you took off with might weird the judges out a bit.
Re: (Score:2, Interesting)
Though telling NASA "the key is to only transport little people" ...
They told the world that. Seriously look up "Promised the Moon". I seem to remember a key argument in the original program was "Women are smaller".
Re: (Score:3, Funny)
Re: (Score:3, Interesting)
I wonder if there are limits on the sizes of the passengers?
The FAA has determined that the "average" passenger weighs 170 lbs for the purposes of advertising how many "passengers" a plane can carry. Thus, a Cessna 172, with 4 seats, but with a fully fueled capacity of about 650 pounds. is a "3 passenger plane" when fully fueled. You can, of course, decide not to fill your tanks all the way, or you fly overloaded.
I agree with another poster, however... 1.5 million dollars is hardly worth getting out of bed
Re:A-380 halfway there (Score:4, Insightful)
Wikipedia says that a Long-EZ will do 1600 miles on 52 gallons of fuel. That's 61.5 passenger miles per gallon. It also typically cruises at 184mph - parasitic drag will be 3.39 times less at 100mph, but induced drag will be 3.39 times greater. I am unable to find a chart of both for a Long-EZ (here is a generic one [aviation-history.com]), but 100mph probably isn't that far off from the minimum drag speed.
I suspect it'll be some variation of a motorglider - probably one that seats at least two. They have much higher aspect ratio wings, much lower sink rates, and would probably have much lower drag at 100mph.
The Voyager around-the-world aircraft (another Rutan creation) did only 41 passenger miles per gallon (averaged across the entire flight), but they were hauling 9000 lbs of fuel towards the start (53 passengers worth). I suspect it could win the challenge right now - but it'd make a lot more sense to build a different one than to unhook it from the Smithsonian ceiling.
Parent
Re:A-380 halfway there (Score:4, Interesting)
Parent
Re: (Score:2)
Re: (Score:2)
Re:A-380 halfway there (Score:4, Informative)
The requirements in the rules [cafefoundation.org], Appendix B, are:
Vehicle height: less than or equal to 13 feet
Vehicle length: less than or equal to 23 feet from main landing gear to tip of tail
Landing gear footprint must fit onto CAFE Scales (See CFTC floor plan, below)
Gross weight: less than or equal to 6500 pounds on main landing gear and less than or equal to 2000 lb on nose or tail wheel
Wingspan (as projected onto a level surface), if less than or equal to 44 feet, must be capable of being shortened to less than or equal to 44 feet by wing-folding or tip removal that can be easily accomplished in 20 minutes or less by no more than 4 adult persons of average size and strength. This is necessary to fit typical tie-downs, hangar rows and the width of the CAFE Flight Test Center's hangar. Any small additional projected span of winglets, tip tanks or other wing tip device, as vertically projected onto a level surface, will be included as wingspan.
--sabre86
Parent
Diesel (Score:2, Informative)
Such technologies and innovations include, but are not limited to, bio-fueled propulsion...
Take a Diamond aircraft and put old Wesson oil in it and Wammo! $1.5 million?! [diamond-air.at]
Their aircraft seam perfect for using bio-fuels. Sure, you'll have to tweak it a bit. No problem.
Blimp (Score:2)
"Passenger miles" the catch. (Score:5, Informative)
Moving four passengers the 200 miles at 100 MPH on four gallons of gas would pull it off. That would be a 'raw' MPG of 50 MPG. Or, in airplane parliance, that two hour trip would consume at an average rate of 2 gph (Gallons per Hour, the normal measurement used in the aviation industry.) A two-place airplane would need to consume half as much fuel to qualify.
A Cessna 172, with four passengers, consumes somewhere between 7-10 gallons per hour. So this would be a serious improvement. There are some 'light sport' aircraft that draw near 4 GPH, but those are two-place.
Either way, still way better than requiring a raw 200 miles per gallon.
They had one of these in the 80s (Score:2)
It was a sailplane. Behind the pilot it had a pusher propeller on a pod with folding props. You could sail all day, just starting the engine when the updrafts were bad and you needed to gain altitude again.
I think the article was titled something like "Fly all day on a gallon of gas."
Re: (Score:3, Informative)
Motorgliders have been around longer than that, but they are just as much "sporting goods" as a pure sailplane is. The auxiliary engine doesn't give you the freedom to travel long distances at will. It does two things: it saves you the $30-$60 it costs to get airborne behind a towplane, and it means that if you run out of thermals you can make it to an airport instead of landing in a farm field and calling someone to bring the trailer. If the weather isn't soarable, you aren't taking any trips.
rj
This the kind of use stimulus funds should be put (Score:2, Insightful)
to...
Seriously, use it to stimulate PRIVATE innovation and investment, instead of trying to manually command-and-control the economy. The government can't do, or direct people to do, things with half the efficiency that entrepreneurs can.
Do the math (Score:3, Interesting)
L/D for a really good plane 50:1
plane weighs roughly 4 times as much as the passengers (proabbly lowball)
passenger weighs 80 kg
speed=100 miph=160 kph=50 m/s
so constant power required=1/50*(4*80)*10*50=3200W
Best engine efficiency ~40%, best prop ~80%, calorific content of fuel is 38 MJ/kg= .8*4*38 MJ/gallon, so fuel consumption is 3200/(.32*3.2*38*10^6) gallons per second. So in 2 hours there are 7200 seconds, so ttoal fuel used is 3200/(.32*3.2*38*10^6)*7200
So, that is 0.6 gallons for 200 miles for one passenger
Conclusion, probably do-able, it'll cost way more than 1.5 million
Whats the big deal (Score:4, Interesting)
Re: (Score:3, Funny)
If you only have one passenger and are going 200 miles on one gallon, probably nothing.
Re: (Score:3, Informative)
You're allowed to spend a gallon per passenger for every 200 miles traveled. So if you have 10 passengers you can spend 10 gallons to go 200 miles.
10(passengers)*200(miles)/10(gallons)=200 Passenger Miles/Gallon.
10(passengers)*400(miles)/20(gallons)=200 Passenger Miles/Gallon.
And so on.
Re: (Score:3, Insightful)
I agree that the NASA administration has had problems, but what's your problem with this competition? If someone wins the competition, I'd say that's 1.5 million *very* well spent. Especially compared to NASA's overall budget.
Also- a lot of NASA's problems are due to how its budget is handled by congress. Space development is a thing of long term projects to make serious headway- but that's exactly what they never have the luxury of, since the budget fluctuates enormously.
Re: (Score:2, Informative)
No they aren't null and void. These planes exist and are on the market today. They are commonly referred to as "gliders".