Hard Light Productions Forums
Off-Topic Discussion => General Discussion => Topic started by: Flipside on October 10, 2005, 04:01:42 pm
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http://news.yahoo.com/s/ap/20051010/ap_on_sc/supersonic_jet
Aparantly, the first serious attempt at high speed commericial travel since Concord, and part of a joint venture between Japan and France to create a Concorde II.
Considering the first test crashed in the outback, I love the Japanese sense of humour....
"Everything was very good and the aircraft landed ... normally," Saito said in a telephone interview.
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Nice to see someones working on it. :)
If it's fairly efficient Japan would have a use for it.
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Lots of research has gone into dampening the sonic boom as well. Hopefully they are taking advantage of that work to make this also the quietest supersonic airliner ever.
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And perhaps we'll one day actually have economy-class supersonic passenger flights for those of us who'll never get a chance to ride the Concorde.
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I'm waiting to see a passenger airliner use the PDWE...
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Given it's Japanese, I have a strong suspicion that it also turns into a giant mecha when you need some extre firepower.
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Of course...whay do you think it chrashlanded the first time!
the stupid pilot forgot that in mecha mode it can't fly!!!
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If the japanese ever come up with a air superiority fighter that transforms into a mech, they'd deserve to rule the world ;)
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(http://www.billygalaxy.com/pics_for_web/mkcaptainscarletimaisuperso.jpg)
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Originally posted by Flipside
http://news.yahoo.com/s/ap/20051010/ap_on_sc/supersonic_jet
Considering the first test crashed in the outback, I love the Japanese sense of humour....
"Everything was very good and the aircraft landed ... normally," Saito said in a telephone interview.
I don't think that's the complete quote. ;P They trunctuated part of it and left in the essential details. That's what they do with quotes all the time when short of space.
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Faster planes means faster engins. Faster engins means closer to (warpspeed) and (subspace engins of FS1).
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...if you ignore a little thing called the laws of physics, specifically general relativity... sure.
Or we just do things Ork style: red goes fastah!
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"Leela, put these flame decals on the ship so it goes faster!"
"What system of logic did you use to determine that?"
"We're 8."
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Originally posted by Charismatic
Faster planes means faster engins. Faster engins means closer to (warpspeed) and (subspace engins of FS1).
As you approach C, your effective mass approaches infinity. Therefore, it's impossible to accelerate to C.
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Actually faster plans means you need *stronger* engines.
On the issue of said engines: our jet engines aren't really good for supersonic flight.
The reason is we can't yet correctly model how air flows at such speeds. The really bad part is therefore we can't design engines that work with pure supersonic airstreams.
What we do is slow the intake to subsonic speads, burn it in the reaction chamber and hope the exhaust goes even faster than the supersonic air in front of us.
(Naturally this means we turned the kinetic potential of the oncoming air into wasteheat - and energy we will have to put back in to have any thrust).
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Originally posted by Charismatic
Faster planes means faster engins. Faster engins means closer to (warpspeed) and (subspace engins of FS1).
He's completely right.
Name me one plane where the engines move slower than the rest of the airframe when in flight.
Ha!
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A crashing one?
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Crashing isn't flight.
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Originally posted by Flaser
this means we turned the kinetic potential of the oncoming air into wasteheat - and energy we will have to put back in to have any thrust
Ramjets.
No moving parts. Just a Venturi.
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Ah...explanations, explanations...anyway:
Ever heard of inertial systems - how they should be interchangable and to do so you must apply certain new inertail movements/forces to an object when switching (and a physicist babbling about lightspeed and so on started it all with the fact light doesn't behave in that manner).
Long and coplicated story short and simple:
-You speak of a system where the air is stationary and the plane along with the engine moves through it.
-I spoke of a system where the plane and the engine are stationary and the air moves around them.
Both systems are correct and give the same answers.
The reason I used the later system is 'cause it better shows the energetic problem of a subsonic engine.
@aldo - You're copletely missing the point.
The air rushed toward the engine at a supersonic speed (or in the first model, the engine goes in the air at a supersonic speed).
However we can't handle air at those velocities - so in the air intake we force the air to expand inside the engine slowing it down to subsonic speeds.
(...and in the process we introduce a horrendour ammount of drag. In the first system this 'loss' of the air's energy is drag on the whole aircraft from the engine)
The process is far from efficient and we loose energy thanks to the pesky second law of thermodynamics.
@Descenterace
You're right - that's one of the solutions.
However there's a problem: we still have ain't no clue on how air behaves at such speeds.
Therefore the whole engine's desing can be summed with a sinlge word: GUESSWORK.
Is it bad? Yep, it's a massive 2 dimensional desing, a huge box (by using a box, we can simplfy all calculations to a plane, the crossection of the box, and therefore things are esier to calculate) that's darn hard and problematic to integrate into any sensible aircraft.
However the only way to learn what really happens is that: GUESSWORK.
The testflights then either proove or deny the clarification.
So, while current ramjets designs are far from the solution, they're the means to achieve the much needed understanding of supersonic airflow dynamics.
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Untill they start fitting Pulse Wave Detonation Engines to commercial jets, I don't care what the Japanese do :)
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so in the air intake we force the air to expand inside the engine slowing it down to subsonic speeds.
Yep, one of the many weird facts I learned in Missile Class. Even ramjets had to do that too, but I think now they have overcome the issue of supesonic airflow through the engine (but not one with blades inside)
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Originally posted by Clave
Yep, one of the many weird facts I learned in Missile Class. Even ramjets had to do that too, but I think now they have overcome the issue of supesonic airflow through the engine (but not one with blades inside)
The term for those is 'Scramjets', which have been tested by NASA and are not exactly ultra-new technology.
Flaser's on something of a red-herring hunt though, because at a flight regime of mach 2 or so I believe ramjets are more efficient than scramjets.
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So let me get this straight: It's going to take them another twenty years to make a plane that already existed thirty-five years ago?
Now that's what I call progress!
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Originally posted by Shrike
The term for those is 'Scramjets', which have been tested by NASA and are not exactly ultra-new technology.
Flaser's on something of a red-herring hunt though, because at a flight regime of mach 2 or so I believe ramjets are more efficient than scramjets.
I'm not arguing wheter any given technology is more efficient than the other.
All, I say is that our supersonic planes use engines that are unsuited for such operation.
As for ram/scramjet I said these tests are one of the few that can give us true insight into supersonic aerodynamics.
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Rockets.
;)
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Originally posted by Flaser
@aldo - You're copletely missing the point.
The air rushed toward the engine at a supersonic speed (or in the first model, the engine goes in the air at a supersonic speed).
However we can't handle air at those velocities - so in the air intake we force the air to expand inside the engine slowing it down to subsonic speeds.
(...and in the process we introduce a horrendour ammount of drag. In the first system this 'loss' of the air's energy is drag on the whole aircraft from the engine)
The process is far from efficient and we loose energy thanks to the pesky second law of thermodynamics.
What the hell are you on about? It's a bloody throwaway joke, get a grip man!
(I'm well aware of the laws of diminishing returns, entropy, e=mc2 and soforth.)
Seriously; the physical parts composing the engine, must move at the same speed through the air as the airframe they are attached to, otherwise... well, they won't be attached to the airframe. Hence, while he's completely off his nut to suggest you can just pump in more and more energy (or whatnot) without penalty, on a literal sense an engine can go no faster, nor slower through the air than the rest of the aircraft. If engine is travelling at 100m/s and the rest of the airframe is travelling at 10m/s - you imagine it (it sounds a bit like rrrrippp...crunch...aaaahhhohgodimgoingtodie....boom!).
Jeebus. I really should not have to explain that, I really shouldn't. Sometimes I think we really do need sarcasm tags.