This is just Plane cool......

[RickM]

12 feet long and 5000 mph. Very cool.

http://story.news.yahoo.com/news?tmpl=story&cid=513&ncid=703&e=9&u=/ap/ap_on_go_ot/hypersonic_jet

[911ctS]

Thats awesome! I love when they come up with stuff like this (and tell us about it).

[RickM]

Yeah, scooping up the oxygen and simutaneously combusting it with the fuel is very cool stuff. Kind of a jet/rocket engine.

[ZOA NOM]

Yeah, but how fast can it stop?

[RickM]

As fast as it can crash...."then coast for a few minutes before crashing into the ocean off California."

That's pretty quick.

[john70t]

There was a crazy german bomber in WW2 (another of the frantic super-weapons that never got developed) called the America Bomber that was supposed to do the same thing: one-way bomber that would get up in space and bounce on the stratosphere around the world.
This project was along with the Me262(first jet), the Go229(wood! radar-proof delta shape jet much like the stealth), the V1(first ramjet), and the V2(first ICBM) amoung others.

Tech junkies should also check out Nicolai Tesla, who's vision back in 1930s was a free worldwide wireless communications infrastructure(umm...the internet?).

Amoung his accomplishments was
-the first AC hydro-electric plant at Niagara Falls (Edison tried to make DC electrical grids work and used AC to fry dogs as an example of how dangerous his rivals tech was)
-the florescent bulb
-the radio (Marconi worked for him and stole the idea. Teslas patent was first and more complex)
-continuous artificial lightning 112 feet high going up from the earth
-the death-ray currently being developed for tommorowsanti-missle satelites
-a pocket sized earthquake machine
-the static charge machine where on can saftley shoot out of their fingertips
-probably a bunch of other things
-and of course, the Tesla coil which powers your car.
Sadly, he died pennyless and alone, and wasen't even mentioned in the Smithsonian until recently

[UconnTim97]

Can I put that engine in my 944?


JK....lol

[island911]

If the high-risk flight is successful, it will mark the first time an exotic jet engine, called a supersonic-combustion ramjet or scramjet, has propelled a plane at so-called hypersonic speeds.

First!?. . .hmmm. . .are they sure about that?

Kelly Johnsons brilliance put together a scram jet, way back. Whether it was hypersonic (+mach5) or not is classified.

However, from this image someone ought to easily figure its design speed.



. . . this looks like it would have to fit in a 15° mach-cone (30° from wing edge to edge)

So, M=1/(sin15°) =3.86 . . .considering I measured the angle, there, with a 30-60-angle (not being too accurate) I would say the design speed, of the D12 drone, was likely mach4.

hmmm, and we're just now looking at breaking the scramjet/hypersonic speed threashold? . . .seems we've been slacking for the last 30 years!

[juanbenae]

i get jokes,,, plane, not plain....

[bell]

there was an interesting article on pulse detonation engines (different from scramjets) in popular science a few months ago..........very interesting stuff........

[island911]

missed that article, but pulse-jets are old-news.

the beauty of the scramjet is that they are very high compression engines. . . their "compression stroke" is a focused shock-wave/sonic boom.

[on-ramp]

so what if it can go 5000mph? that's nowhere close to the speed of light.

186 000 miles per second.
However,
the speed of light depends on the material that the light moves through - for example: light moves slower in water, glass and through the atmosphere than in a vacuum. The ratio whereby light is slowed down is called the refractive index of that medium.

which leads me to my next observation. Why are the planets round and not cubicle?

[Superman]

One of those SR71 planes, complete with the third "piggyback" engine, is at the Boeing Museum of Flight. There is also an SR71 cockpit you are welcome to sit in. Guys, I dunno about you but I never wanted to be a fire fighter or a police officer..... but astronaut or test pilot, you betcha.

The SR71 engine did utilize a strategy of compressing the air coming into the engine by virtue of a cone that extends out the center of the engine. This did creat a 'ramjet' effect, probably not quite the same as this SCRAM technology, but effective enough in the low-to-mid mach numbers.

[MFAFF]

The SR-71 has a sort of twin cycle engine....the intake produced the majority of thrust, in the order of 70% when crusing a M3+ with the combined exhaust/ reheat section producing a further 22%, leaving the J-58 engine producing only 8%.
However without that core engine producing the thrust the ramjet cycle could not be sustained. At lower speeds the bypass tubes running around the engines are not working correcty and their % contribution dimishes to leave the J-58 working as a jet engine.....

The D-21 recon drone was powered by a ramjet engine, a hollow tube that uses the compressive effects of M1.25+ airflow to compress the air and a simple fuel pump and igniter system to burn the fuel to produce thrust. However it still needs a shock cone, the cone you see in the inlet, to moderate the airflow to below M1 within the combustion section. The cone itself needs mechnaical adjustments etc and a control system to make it work.

The SCRAMJET takes this one step further and does away with the inlet shock cone. The whole idea is to burn the fuel in a supersonic airflow.....getting rid of all the moving parts of the engine entirely....

Imagine trying to get your lihgter to burn whilst holding it out of your P-car window a 150mph.....

The exhibit in Seattle is a M/D -12 combination.
The M-12 'mothership' is derived from the A-12 Balckbird, forerunner of the SR-17 and the D-21 Tagboard drone vehicle. This was designed as a free flying drone, destined for covert overflights of hostile territory (Gary Powers anyone?). Once its preprogrammed flight was done it was designed to jettison the camera module to be recovered inflight from a parachute and then self destruct.

Following an inflight collision between a M-12 and D-21 at launch resulting in the drowning of the Launch control officer the program was cancelled.
The D-21 was adapted to be carried aloft under a B-52 with a booster rocket pack, as will be the X-43. Two operation missions were launched, one drone vanished entirely and the other, altohugh succesful in ejecting the module it was lost during the recovery.
After that the program was abandonned.

[island911]

Originally posted by Superman
. . .

The SR71 engine did utilize a strategy of compressing the air coming into the engine by virtue of a cone that extends out the center of the engine. This did creat a 'ramjet' effect, probably not quite the same as this SCRAM technology, but effective enough in the low-to-mid mach numbers.

The cones (note: staight cone sweep) on the SR71 are adjustable to keep the shockwave OUT of the engine intake. (the air on the backside, of a sonic wave, will be subsonic . . .the cone keeps the engine feed with sub-sonic air)

The cone (note it has parabolic sweep) on the drone is such, that the shockwave is focused into the engine intake. (thus the sonic-compresion ram . ..scramjet effect)

[MFAFF]

The cone, on both the SR-71 and the D-21 is adjustable to maintian the shock wave in exactly the correct position.

As the behaviour of the shock wave is dependent on the air temp, the humidity, the exact angle of attakc of the cone etc etc it is constantly shifting and the cone needs to respond, albeit by fractions of an inch.

The SR-71 powerplant functions as a partial ramjet at M3+.
The Maraquardt ramjet in the drone is a pure ramjet, needing subsonic air within the combustion chamber to sustain combustion.

The SCramjet, Supersonic Combustion ramjet does what is says on the tin....the combustion cycle takes places in airflows greater than M1.

The intake cones are designed to capture a shock wave from the tip to the inside of the intlet tunnel. It is then reflected down onto the cone afterbody within the inlet and a series of 'standing shock waves' serve to slow the air down whilst compressing it.

Whilst this creates sufficient compression in the ramjet to sustain combustion, in the J-58 engine the turbojet core is still needed to ensure the reheat section, used continously in supersonic flight remains ignited and can use the highly compressed air which has been diverted around the core engine and dumped upstream of the a/b nozzles.

If for some reason the shockwave in the J-58 loses its focus, and it 'escapes' the lip of the inlet the resultant loss of thrust and increase in drag is sufficient to slam the pilot's head against the canopy.
The inlet is said to have suffered an unstart an the cone needs to be cycled inwards before moving outwards again to recapture the shock wave.

[DanTheCat]

The SR-71 is an amazing plane. Have they declassified it's top speed yet? I thought they have admitted to at least mach 5 with the SR-71.

Dan

[john70t]

The SR-71, probably one of the greatest unknown planes in history, has been obsolete for quite a while

[ronin]

Originally posted by john70t
Tech junkies should also check out Nicolai Tesla, who's vision back in 1930s was a free worldwide wireless communications infrastructure(umm...the internet?).

naah, that was the CB radio

[beepbeep]

Originally posted by DanTheCat
The SR-71 is an amazing plane. Have they declassified it's top speed yet? I thought they have admitted to at least mach 5 with the SR-71.

Dan

Fastest speed was M3.2. Material-limitation was at M3.4.