[Fineus]

Untill they start fitting Pulse Wave Detonation Engines to commercial jets, I don't care what the Japanese do

[Clave]

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)

[Shrike]

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.

[Rictor]

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!

[Flaser]

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.

[Descenterace]

Rockets.

[aldo_14]

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.