OT: The future of aircraft propulsion

[Poopskadoop]

When the inherent limitations of the prop engine were discovered, the inevitable next step was to develop a radically new engine that was not susceptible to the weaknesses of the propeller, thus the turbojet was born, followed by the turbofan, etc.

 

Well, it's been over 60 years that we've had this technology, and we've been pushing it to the max. I know a lot of you have very technical knowledge about jet propulsion systems. :) What do you think will be the future of aircraft propulsion? Will we ever see the day when a fighter aircraft can achieve mach 2 without dumping its entire fuel load over the course of a few minutes?

 

I once read something about a nuclear powered jet engine, but it was deemed impractical for some reason. Are there any other possibilities? Better fuels? Better materials for the combustion chamber?

[britgliderpilot]

When the inherent limitations of the prop engine were discovered, the inevitable next step was to develop a radically new engine that was not susceptible to the weaknesses of the propeller, thus the turbojet was born, followed by the turbofan, etc.

 

Well, it's been over 60 years that we've had this technology, and we've been pushing it to the max. I know a lot of you have very technical knowledge about jet propulsion systems. :) What do you think will be the future of aircraft propulsion? Will we ever see the day when a fighter aircraft can achieve mach 2 without dumping its entire fuel load over the course of a few minutes?

 

I once read something about a nuclear powered jet engine, but it was deemed impractical for some reason. Are there any other possibilities? Better fuels? Better materials for the combustion chamber?

 

Combustion chamber isn't the problem - because the flame burns slowly you burn it within a stream of faster moving air, effectively insulates the combustion chamber walls.

 

The problem is the first stage turbine - which actually comes into direct contact with the hot gases. They're up to and above 2000 Kelvin now, not much more is possible with metal (even air-cooled and ceramic-coated), and AFAIK ceramic is still too brittle.

 

There are certainly advances to be made, but they're incremental at this point. Putting F-119/F-135/EJ200 tech into a commercial engine is still possible, and expect to see it a couple of years down the line.

 

 

Don't know of anything truly revolutionary in the pipeline at the moment. Just further advances of the turbine concepts.

 

The obvious problem with nuclear engines was the fallout and the shielding. Difficult.

 

Hydrogen-fuelled engines work for zero-emissions, but then you have the problems of carrying refrigerated liquid hydrogen. Not to mention the problems of actually producing all that hydrogen in the first place . . . .

[Force_Feedback]

Not to turn this into some flaming thread, but why does the EU want to tax airlines for emissions? I mean, in my country, the total percentage in CO2 emissions from aircraft (all kinds, also the ones on transit) is slightly below 1.5%, and that for such a small country with a large airport and lots of traffic. In my vision it is some cheap trick to earn some cash. And if they want to screw someone, why not take on the automotive branch, which accounts for 69% of mobile pollution.

I know it's slightly OT, but why bother to invoke such taxes when the engine and airliner manufacturers try their best to minimise emissions already?

Sounds the same like not being allowed to fart, because of the methane, while a single cow farts up more methane than like 300 humans :s (Heh, what an example :P)

[leafer]

Laser? Saw something about NASA researchers working on using laser as a mean to move objects into space. I don't remember the scientist's name, but he demonstrated the technology and it's pretty interesting.

[Pilotasso]

What about that super fast spinning ring technolgy that apears to decrease gravity to objects on its axis of rotation?

 

Now that a total out of this world concept.

 

Laser propultion, I dont see it hapening. Depends on an established source of light external to the craft. Thats an awfull way to to travel, not only accleration takes a long time but to get anywhere you would have to depend externaly for your propultion for ages, literaly.

Its wouod be only viable for inter system travel, its too slow for inner system space. And then if something happens on earth your drifting on space forever. And its a one way voyage too.

 

I think this is one of these white elephant dreams that happen when simply theres not enough maturity yet to realize the full consequences of its aplication.

[hitman]

http://en.wikipedia.org/wiki/Pulse_detonation_engine

[Pilotasso]

LOL nice new Avatar.

[EscCtrl]

There are plenty of ideas out there but none of which will be seen soon - the newest stuff to be introduced to civilian aircraft would be fly by wire controls and electronically driven systems - whilst this doesn't sound like much it would increase reliability incredibly and decrease weight.

 

Ideas like using magnetically driven gearing for frictionless and stronger control as well as the fact you cannot break the gears as there are no teeth or points of contact - it is one of the current breakthroughs in the A380 projects

 

 

 

Keeping on topic in terms of future propulsion systems the ideas that I think will have a big impact will be Ion jets and the RAM jets including SCRAM jets of various forms (perhaps one day we will have nuclear powered SCRAM jets?) there is a lot of potential there and it seems the next logical step from jets - the only problem is the lack of slow speed power.

[Pilotasso]

^^^^Your a little late on that score. Airliners already have FBW for some time.

[EscCtrl]

Heh so I did some reading on the Pulse Detonation Engine and it got me thinking - with advances in engine material and engine control would it one day be possible to build an engine that starts off as a PDE i.e. encloses the fuel mixture by shutting off the front and detonating the force that ensues out the rear until the plane achieves a desired supersonic speed whereby the engine is reshaped (through hydraulic rams or the future equivalent (electromagnetic gearing as i mentioned earlier) to take on the shape of a scramjet (probably by opening the front valves and aligning them accordingly) so air is automatically compressed without the need for the detonation to be controlled (or for any real detonation, instead replace it with a constant fuel supply and combustion process?

 

This would solve many problems - though would be incredibly complex

 

 

 

 

P.S. if that makes sense to anyone and has not already been thought of its copyright of EscCtrl 2007 :P

[TucksonSonny]

Not to turn this into some flaming thread, but why does the EU want to tax airlines for emissions? I mean, in my country, the total percentage in CO2 emissions from aircraft (all kinds, also the ones on transit) is slightly below 1.5%, and that for such a small country with a large airport and lots of traffic. In my vision it is some cheap trick to earn some cash. And if they want to screw someone, why not take on the automotive branch, which accounts for 69% of mobile pollution.

I know it's slightly OT, but why bother to invoke such taxes when the engine and airliner manufacturers try their best to minimise emissions already?

Sounds the same like not being allowed to fart, because of the methane, while a single cow farts up more methane than like 300 humans :s (Heh, what an example :P)

 

Did you know that all the farting cows and pigs together in my country (Belgium) produce more CO2 emissions than all the cars together produce! ;)

[leafer]

LOL nice new Avatar.

 

According to the adults over der at simhq, avatar is for pre-teens, juveniles, wussies, strippers and crackheads. So which one are you? :D

 

So I'm thinking about replacing my avatar with something... Humm....what could it be...Hey! Neone has some lame quote I could use for my sig? Oh wait, I'll just take one from simhq. :D

[Prophet]

Did you know that all the farting cows and pigs together in my country (Belgium) produce more CO2 emissions than all the cars together produce! ;)

 

I thought that was methane?

[Poopskadoop]

There are plenty of ideas out there but none of which will be seen soon - the newest stuff to be introduced to civilian aircraft would be fly by wire controls and electronically driven systems - whilst this doesn't sound like much it would increase reliability incredibly and decrease weight.

 

Ideas like using magnetically driven gearing for frictionless and stronger control as well as the fact you cannot break the gears as there are no teeth or points of contact - it is one of the current breakthroughs in the A380 projects

 

 

 

Keeping on topic in terms of future propulsion systems the ideas that I think will have a big impact will be Ion jets and the RAM jets including SCRAM jets of various forms (perhaps one day we will have nuclear powered SCRAM jets?) there is a lot of potential there and it seems the next logical step from jets - the only problem is the lack of slow speed power.

 

Ion jets? Sounds like science fiction. How would that work?

[Poopskadoop]

I think the biggest limitation future fighters will face is the human body's g-tolerance and the tolerance of the the structure itself under high g. Still, being able to cruise at mach 3 would offer a considerable tactical advantage. :pilotfly:

[Mizzy]

We all know what the propulsion of the future is and its been around since the mid 1960s!!

 

Basically its using dylithium crystals for the warp engines and warp factor 8.

 

When we move from fossil fuels and discover crystolic fusion (as opposed to double AAs) this will help us to reach Star Command.

 

Hope this helps anyone who was in doubt about the future travelling arrangements.

 

Mizzy.

[Groove]

I saw once a report on tv about american efforts of building a nuclear powered engine. the project stopped in the early 60s, its obvious why ^^