The Aviation Thread [Contains Lots of Awesome Pictures]

Cold Fussion

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Yes per nautical mile they use less fuel because they are flying faster at a higher efficiency level of the engine, per unit time they burn more fuel operating at 3600km/h then they would at 500km/h. This is exactly what efficiency means.
 

Labcoatguy

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No, fuel efficiency is measured by distance per amount consumed (e.g. MPG) or its inverse (e.g. l/100km). Fuel use per unit time is pointless if speed (and therefore distance) isn't part of the final calculation.
 

Cold Fussion

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No, fuel efficiency is measured by distance per amount consumed (e.g. MPG) or its inverse (e.g. l/100km). Fuel use per unit time is pointless if speed (and therefore distance) isn't part of the final calculation.
I already said in my previous post that fuel efficiency is the fuel use per distance traveled. But That doesn't mean you use less fuel when flying faster, the amount of fuel you burn is calculated against time as it is constant. I said in my initial post that it may be more efficient, and turns out is is, but it doesn't use less fuel flying at a higher speed. The SR-71 is most efficient when flying around at mach 3, but it also uses the most amount of fuel when flying around at mach 3.
 

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The SR-71 is most efficient when flying around at mach 3, but it also uses the most amount of fuel when flying around at mach 3.
Just to clarify, are you talking about fuel consumption per unit time when you say "uses the most amount of fuel when flying around mach 3"? If so, then we're only disagreeing on terminology; I think of fuel use per unit time as a measure of consumption irrespective of efficiency.
 

Cold Fussion

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Just to clarify, are you talking about fuel consumption per unit time when you say "uses the most amount of fuel when flying around mach 3"? If so, then we're only disagreeing on terminology; I think of fuel use per unit time as a measure of consumption irrespective of efficiency.
Yes I am. I think of it the same way, and I'm saying the consumption is higher the faster it flies.
 

SpitfireMK461

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Yes I am. I think of it the same way, and I'm saying the consumption is higher the faster it flies.
Yes, but the point seems to be that it's speed would increase faster than it's fuel consumption, thus making it more efficient (that is, less fuel per distance traveled) as it gained speed. I believe this is a symptom largely of the J-58's bypass system. As it increased in mach, more and more inlet flow would bypass the core and be introduced straight to the afterburner. At low machs this is similar to a low bypass mixed turbofan, such as in use in the F-15 and other fighter jets, then essentially becoming a ramjet.

Something to say about supersonic business jets. In relation to the Concorde, it was designed with the ability to supercruise, but also with afterburners. The idea was that supercruise would be more efficient than afterburners, but after being put into use, they found the afterburner was actually more efficient at getting through the sound barrier than supercruising.

As any group at my school (or any school) that has had to design a super sonic business jet before, the gist of the problem is fuel consumption; they do a lot of consuming.
 

Ramseus

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FedEx airplane delivery service. All packages must be packed to withstand a five foot drop.

Getting to the destination faster and consuming less overall in less time is still using less fuel than getting there slower and using more fuel. Semantics don't change that.
 
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Heathrow

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Thurston TSC-1A Teal

A bit of a rare bird, this Teal was in a movie.
An e-cookie for anybody who knows which one, without Googling.

:cool:

FedEx airplane delivery service. All packages must be packed to withstand a five foot drop.

Getting to the destination faster and consuming less overall in less time is still using less fuel than getting there slower and using more fuel. Semantics don't change that.
And speaking of integrators, UPS seems to have failed a UK Government Security audit.

BBC News - UK government ban on UPS air cargo screening

Ooops, UPS. :lol:
 

flyinhawaiian

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No chit... does anyone else have the "Imperial March" (from Star Wars) playing in their head with that picture? lol
 

nsx_23

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Throw a T-50 into that pic and the world will implode with awesome.

Forgot to add - go "view image" if you want the high-res to use as a wallpaper.
 
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Cold Fussion

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Hypersonic: Paris-Tokyo in two and a half hours
By Victoria Bryan

LE BOURGET, France | Mon Jun 20, 2011 5:16am EDT

(Reuters) - Fancy travelling from Paris to Tokyo in two and a half hours? Do you yearn for the Concorde days?

Aerospace group EADS (EAD.PA), owner of planemaker Airbus, thinks it has the answer -- a hypersonic jet that flies above the atmosphere, yet takes off from a regular runway.

"It is not a Concorde but it looks like a Concorde, showing that aerodynamics of the 1960s were very smart," Jean Botti, EADS' chief technical officer, said.

By flying above the atmosphere and using biofuel to get the plane off the ground initially, the group hopes to avoid the supersonic boom and pollution Concorde was notorious for.

"When you are above the atmosphere nobody hears anything," Botti said.

The plane, being developed in collaboration with Japan, is being primarily designed with the business market in mind and could carry 50-100 passengers.

The concept project, known as ZEHST (zero emission high speed transport), comes as companies such as Virgin Galactic push forward with plans to take paying customers up on commercial space flights. Indeed, ZEHST is being developed using research from EADS' space arm Astrium.

Unlike Virgin Galactic customers, EADS says ZEHST would have a maximum acceleration of 1.2G, meaning passengers will not need any training in order to fly.

"The acceleration on people is very low, so no specific equipment or training is needed," Botti said.

The plane will take off using a regular turbofan engine, before rocket boosters kick in to start a sharp ascent, sending the plane soaring above the atmosphere.

Ramjet engines, currently used in missiles, will then take the plane up to altitudes of 32km as the plane cruises at speeds beyond Mach 4, or four times the speed of sound. After a gliding descent, the turbofans will reignite to enable landing.

"ZEHST has no novelty, it is all things that have been created before," Botti said, adding the company could have an unmanned demonstrator by 2020.

EADS boss Louis Gallois warned it could be another 30-40 years before commercial flights are a reality.

"We're not talking about a product that we launch in the next few years. We have to see security, integration of different technologies, how man reacts to it."

(Additional reporting by Tim Hepher and Cyril Altmeyer; Editing by David Hulmes)
http://www.reuters.com/article/2011/06/20/uk-airshow-hypersonic-idUSLNE75J01G20110620

I don't like how they 'intend' to use rockets. Why not use a bypass type engine like the sr-71? I'm looking at you nsx_23.
 
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Eye-Q

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zero emission high speed transport
That's interesting, I always thought "zero emission" means, well, you don't burn any fuel so there is no emission (electric cars are zero emission when they drive but the electricity has to come from somewhere, that's why they aren't really "zero emission"), but turbofan engines and rocket boosters do tend to burn fuel...

Nonetheless, in 40-50 years time (unmanned demonstrator by 2020 + 30-40 years to get the real deal) I don't think there will be any need for this because holoprojection or beaming or something else will be that advanced that you a) don't need to be on site or b) you will get there much quicker.
 
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