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Australian Scramjet Launched
CaptainAlbert writes: "The University of Queensland, Australia is reporting the (possible) success of their "HyShot" scramjet test. The BBC have got this covered too. Apparently, they're now poring over the data loggers, trying to figure out if it actually flew under its own power." We had a story about these guys a while back.
We've bought a lot of bits and pieces off the shelf from automotive shops
I think they answered their own question.
They say in the BBC article that the US first achieved the supersonic combustion bit a few weeks ago. But, IIRC, the russians tested a ScramJet a while back, also from a rocket - and succeeded. Of course, poor funding probably delayed/cut further research, which is a shame - they're excellent at experimental (vs. theoretical, simulated) research.
I don't have references, unfortunately... but I'm sure google might provide some...
And let's not forget, ramjets have been in use for quite a while - again, the russians being in advance on the west, check out their air-to-air missiles.
Anyone reminded of those supercavitation torpedoes? Yet another area where those "technologically backward" russians are by far more advanced than the west...
Just how much brainwashing do we get?
My concern is whether there is actually a demand for supersonic flight, or whether the current conventional airliners represent the 'good enough' level of technology which means there is no incentive to replace them. The current state of the travel industry makes me think it will be a long time before we see a scramjet based airliner at JFK.
In the meantime, the Europeans seem to be about to revive the Concorde. Its a bit annoying that we don't have anything to beat that. Maybe these superjumbos will be as impressive, but they won't be supersonic
Look at the shape of the vapour trail. Considering how crazily it wobbled, does it look like a successful rocket launch? Can you even imagine it doing that at Mach 5?
Ceci n'est pas une sig
But it makes sense since it was the point in the flight where there is the highest speed and best chance of engine ignition
but this also means the test engine is usually destroyed instead of being saved for the next test run
"It is a greater offense to steal men's labor, than their clothes"
Experts say scramjet technology has the potential to reduce the flying time from London to Sydney to two hours, and substantially cut the cost of space launches.
...
But the big problem is that scramjets only start to work at speeds greater than five times the speed of sound, or Mach-5.
Parte the firste: The idea is put forth in the BBC article that a scramjet could cut down flight times from London to Australia - great when you've got the hankering for an oil can of Foster's.
Patre the seconde: It is stated that scramjets only work at speeds in excess of Mach 5.
... I'm pretty sure that most people would pass out long before the scramjet would even take off - and without the aid of the beverage cart. I can see the use in space launches, but for commercial apps it is likely quite limited for the above reason.
An aside: If you're into rocket history, there is a recent biography of John Parsons called 'Sex and Rockets'. Parsons was one of the earliest innovators of rockets and solid fuel technologies associated therewith. He was among the handful of people at CalTech who helped take rockets out of science fiction and into reality. Worth the read.
Sir, could you please float back to your seat? We'll be reentering the atmosphere soon.
No, I think the Concorde is safe, for now.
- If the initial stage consumes so much fuel and the fuel to weight ratio is such a big deal in rocket science.
- Why don't they launch rockets from under water using that submarine ICBM technology and leverage the floatation benefits for better performance?
Then again maybe their is something to being a "rocket scientist" and I should stick to my knitting. I know the
A bit of Googling revealed the following:
From The Ramjet/Scramjet Engine:
- a scramjet is a kind of ramjet
- "A ramjet has no moving parts and achieves compression of intake air by the forward speed of the air vehicle. Air entering the intake of a supersonic aircraft is slowed by aerodynamic diffusion created by the inlet and diffuser to velocities comparable to those in a turbojet augmentor. The expansion of hot gases after fuel injection and combustion accelerates the exhaust air to a velocity higher than that at the inlet and creates positive push."
- "Scramjet is an acronym for Supersonic Combustion Ramjet. The scramjet differs from the ramjet in that combustion takes place at supersonic air velocities through the engine. It is mechanically simple, but vastly more complex aerodynamically than a jet engine. Hydrogen is normally the fuel used."
Scramjet research seems to be a hot topic in the aerospace world - I saw references to projects underway in the UK, in the US Defense Department, at NASA, and of course Australia, all of which have claimed some or other big advances in the past year or so.Finally, here's Scientific American article that gives a bit more technical detail.
Lots of top developments have been made by these sorts of projects while large funded defence projects fail miserably.
Look at how long the Russian's could keep people in space. And of course the ultimate
US: We spent millions of dollars developing this pen which will work in Space or underwater, what did you do
USSR: We used pencils and crayons.
Millions of dollars on one side, 5 cents on the other.
Defence is stupidity with a budget.
An Eye for an Eye will make the whole world blind - Gandhi
I assume that it'll take a while to get up to full speed (not least because I don't think passengers would like being squished by a big acceleration). So if you were going, say, London to Paris you're not really going to have much time to get up to speed. What sort of distances do you need to cover before this option becomes worthwhile (i.e. more economical)? Would London to NYC be far enough? How about LA to Tokyo?
So, how is this supposed to work? Get in your plane, accelerate up to mach 5, wait for scramjet to kick in, cruise for a while, then land. At mach 5 it takes under an hour to fly across the Continental US. Of course, you need to accelerate up to mach 5, unless you want everyone tossing their cookies you can't do that too fast. It'll probably take 1000+ miles of the trip just to get up to speed. Another 1000+ to decelerate.
;)
Basically we've reduced this to those who fly half way around the world. And how many people do that often enough to make up for development costs? It aint ever going to happen. You're better off waiting for them to invent a transporter. The number of people with the desire for this kind of service is simply way too small.
That being said, its fun technology to watch, but you'll never see it used in the commercial airlines. And no, I didn't actually read the article
.. I remember when I studying at UQ, that they had built a hypersonic wind tunnel. The stream of gas could punch holes in sheets of steel.
A mate of mine was researching how to make a mass spectrometer that could work inside/with the wind tunnel. To do the scramjet research, given the speed of the gasses, they needed to know if they could achieve combustion inside the engine rather than several kilometers behind it!
Simon
The first German rocket scientists supposedly freaked out the same way you did, when they couldn't figure out why their guidance systems still left their rockets apparantly wobbling in all directions. It turned out not to be the guidance systems at all - just the wind. The rocket paths were straight, but shifting winds at different altitudes blew them into crazy lightning-strike looking things as the rocket was still aloft. I'd be surprised if the same phenomenon wasn't the explanation for that photo.
This reminds me a little of what happens in third-world countries (I've spent many years in a couple of them). You don't need a drain system if your town is on a hillside leading down to the ocean. But every time it rains hard, the streets flood and you can't get around. No town in most developed nations would be built without a drain system, no matter how convenient the local geography. And the result, in the end, is that more gets done, in a more sustainable way.
Extrapolate that attitude, and you've got the space pen. The people using the pencils and crayons are no longer able to mount space missions without outside help.
And yes, it shows. :)
The point about the "London in two hours" thing is that it gives you a frame of reference. This is mass media we're talking about, not The Journal of Astrophysics. An enormous point about the scramjet is that if it worked, it would allow vehicles to exit the atmosphere without the heavy multiple stage disposable rockets and large amount of fuel that is currently required. In theory, this could turn space travel into a commute.
Some posters seem to be under the impression that a SCRAMjet/RAMjet powered "plane" would need to spend an hour accelerating to speed in order to keep people from passing out or heaving guts, etc.
It's not nearly that bad.
People can generally withstand sustained G forces in the neighborhood of 8 Gs if properly supported. That works out to about 200 miles per hour per second. 5G to ignite the scramjet is about 3800 mph sea level, close enough to use 4000 mph back-of-the-envelope to get 20 seconds to scramjet ignition, maybe 40 seconds to Mach 10.
A two minute climb should be very endurable.
The limiting factor is more likely to be power-to-weight ratios than G-forces.
What are the implications with regard to terrorism? Seriously. As we have seen a 747 full of fuel is very effective bomb, wouldn't one of these be so much worse due to momentum?
Except that if you have an aircraft that cruises at Mach 5 at 80,000 feet no way is it likely to be able to fly at anything like that speed at sea level. It would literally melt.
My other thought is, if they travel so fast, what mechanism will be used to slow them down at the other end? Just air resistance?
Most likely same way as any other aircraft, controlled descent into more dense air combined with deployment of flaps. Just that you'd need to start the descent a lot earlier, which isn't a problem, since you have more alititude to lose anyway. Remember that the shuttle orbiter manages to get down to 200 odd knots from orbit.
I had a high-school friend who went into the Navy and spent time on a sub. This was back in the 70's, so things may have changed since then, but...
According to him, those things were *immensely* manual. He described some valve that was part of the diving process being behind/beside his bunk. When the dive alarm sounded, he (or whoever was bunking at the time) had to turn that valve. He got to where he could do it in his sleep and never know he had touched the valve.
From my own tour of the Battleship Massachusetts, that thing was a giant machine where some of the moving parts happened to be people. It took 25 men to keep one of the 5" gun turrets firing and fed with ammo, and 125 men for a 16" gun turret. There wasn't much automation. Granted it was WWII, but it also signifies a mind-set. I've been through the Albacore and Nautilus (both 50's era, I know) and have seen nothing to refute that mindset.
I can readily believe that opening the torpedo door was someone's personal responsibility, and perhaps he was even sleeping between torpedos at the time.
The living have better things to do than to continue hating the dead.
I bet it wouldn't be too hard to get that limit relaxed to something like no sonic booms below 15,000 feet (~4500m). A military plane once passed Mach 1 less than 2,000 feet (~600m) above the house of a friend of mine (at the time, he was living about forty miles west of Detroit in a rural area). He said it was really loud and shook the Earth, therein lies the problem. Moving it higher off the ground, is IMHO, a much better solution than an outright ban. In that regulatory environment, I can imagine the major hubs having regular supersonic connecting flights to each other, with conventional flights to all other airports. Think of it as a 'backbone network' for 'people packets'.
I like to play children's songs in minor keys.
"We're all sons of bitches now." --J. Robert Oppenheimer
Ok, everyone seems to think I'm either dumb or a troll.
Hey, I understand how normal airplanes slow down. No need to be patronizing. I still think the issue of how they slow down is a valid question - I don't think it is as simple as some people are implying. For instance, the shuttle has terrible problems with heat as a result of air friction on descent.
With regards to the terrorist issue, I wasn't meaning it to be a troll, but I understand people are very sensitive about these things at the moment.
Finally, if you're going to call someone a jerk, please at least have the decency not to do it anonymously.
It all depends on the Requirements:
If what was needed was a tool to allow an astronaut to take notes while in Space, then the end result in both cases was that the problem was solved, altough the pen approach was clearly the LEAST efficient use of the available resources (time and money).
On the other hand, if what was needed was a system to deposite a fine layer of an ARBITRARY liquid or soluble substance (for example special inks), then the pen approach was the only one to solve that problem.
many times
The US Space program used ordinary pencils in space throughout the Mercury and Gemini programs. Paul Fisher, founder of the Fisher Pen Company, spent over one million dollars of his own money developing the Fisher Space Pen before he came up with a working prototype in 1965, which he submitted to NASA for evaluation. NASA approved it for space flight in September 1965, and purchased 400 pens at $2.95 each in December 1967. The Soviet space program adopted them in 1968.
Why is it that the proponents of "one nation under God" are so eager to get rid of "liberty and justice for all"?
My favorite version of the rocket car story:
http://www.ddave.com/rocketcar/
Read it. Yes, it is long - but it is arguably the best story on the internet...
So - is this the truth about the rocket car? Or is it...something else?
I leave that for you to decide in the end...
Reason is the Path to God - Anon
Accelerating at 1/10g (3.2 ft/sec/sec) to keep the passengers comfortable:
Mach 5 = 3000mph at high altitude = 4400 ft/sec
Time to reach this speed: 4400/3.2 = 1375 sec = 23 minutes
Distance covered while accelerating: 1/2(4400)(1375) = 3,025,000 feet = 573 miles
And your deceleration is going to be at least as long, so it's not worthwhile on trips much shorter than LA-NYC.
If the customers can be less comfortable, accelerate at 1g and your acceleration covers 57 miles in 137.5 seconds. But the ticket is going to be very expensive -- the plane has to go faster than most fighter jets BEFORE it can turn on the scramjets. So it needs ungodly big conventional engines, or else rockets. And the seats have to swivel around because you really don't want to hang from your seatbelt in 1g deceleration for 2 minutes.
Someone mentioned accelerating at 8g. This only takes 7 miles -- you could launch from an electromagnetic catapult to scramjet speed, IF the scramjets will run in thick air at low altitude. Of course, your passengers need a thorough physical, and there is still that deceleration issue.
Scramjets are not for airliners. The military applications should be obvious -- and you can use something like the space shuttle boosters in that case. Other than that, they might be useful for space launches -- get to Mach 5 with solid-fuel rockets, then use the scramjets to get to the outer fringes of the atmosphere at Mach 15 or so before you have to switch back to rockets. (The trouble with rockets is that they carry their own oxygen, which outweighs the fuel...)
Having said that, the current thought in naval design is a balance between low manpower automation USS Yorktown Smart Ship and the arsenal ship and manpower for flexibility and most importantly, damage control
Somewhere, something incredible is waiting to be known. -- Carl Sagan
Seriously.
The point of the scramjet is that you don't need to carry a supply of oxygen onboard once you reach those speeds, which are NOT that fast if you consider orbital velocities. That's a HUGE weight difference.
The idea is that you get enough compression at those speeds that you can force enough oxygen into the chamber to burn fuel without the need for a supply of liquid-oxygen. Of course, you may still need that liquid oxygen in space, when you have no atmosphere.. but still.
The whole point is to save fuel on the way up.
A working scramjet is MUCH more efficient than a non-scramjet.. why else do you think they are doing this?
The intended application is a) super fast flight (missiles, cargo) and b) Space launch.
The high speeds needed to start the scramjet engine are not such a problem. The scramjet elimenates the need to carry MASSIVE amounts of oxygen to run the engine at these speeds. In a scramjet, once you reach mach 5 or so, you can stop using onboard oxygen... so you can either launch with less on board (less weight, more efficient) or keep more on board for when you leave the atmosphere behind you (longer trip, more maneouverability, more efficient)
This is definitely the best tall tale of the 20th century. (If you're browsing at too high a level to see the parent post, it just gives this URL:
http://www.geocities.com/Baja/Canyon/7665/)
How do I know it's a tall tale? They welded the railroad cars to the Impala's frame. Then they used air shocks to rase the Impala, so that when they let the air out, the car body would come down and press the crossbar down on the tracks to brake it. But just exactly where did they attach the shocks? The only way that would work is if the railroad cars were welded to the springs, but then I think it would come apart before it got very far. Also, the pipe-mount for the rocket was welded "to both the rear railroad car and the frame."
Other things. Assuming a JATO bottle sold as surplus in the 70's probably originated pre-1950, it probably wouldn't have been that powerful (to drive a 1-1/2 ton car 0-200 in 2.2 seconds). Few WWII planes were all that big, and I don't see where you could attach something that powerful without damaging the plane...
But it's a hell of a story.
During that era, they certainly were. I had a look at an Australian Oberon diesel submarine from the era (it's moored at the maritime museum in Sydney), and to make it do *anything* was incredibly complex. Firing a torpedo required adjusting half a dozen different valves, manually loading the torpedo from storage, and so on.
As well as the controls on the bridge, though, they were duplicated in various other parts of the ship, so if the bridge controls were damaged you could launch a torpedo from the crew quarters, IIRC. They basically slept next to them.
Of course, these days you could replace most of that with a controller and some relays. It'd be interesting to have a look at a Collins-class sub to see how much of the fire sequence is now automated.
Any sufficiently advanced technology is indistinguishable from a rigged demo
--Andy Finkel (J. Klass?)
From this article
"We've had to build all sorts of ancillary equipment, and do it on the cheap. For instance, one of things we had to do is ensure that the payload's spin was correct. To get the spin balance right we bought a second-hand car tyre balance from Bob Jane. It works beautifully!"
Apparently it didn't do what it should have after all. http://www.uq.edu.au/news/index.phtml?article=2567