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New Jet Engine Tested 258

SpaceAdmiral writes "A revolutionary new jet engine has recently been tested in Australia. It is hoped that the engine, designed by UK defense firm QinetiQ and capable of Mach 7.6, will pave the way for ultra fast, intercontinental air travel. Scramjet (supersonic combustion ramjet) engines have no moving parts and take all of the oxygen they need (to burn hydrogen fuel) from the air, allowing for larger loads than rockets which must carry oxygen for fuel."
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New Jet Engine Tested

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  • by xmas2003 ( 739875 ) * on Sunday March 26, 2006 @04:37PM (#14999387) Homepage
    Here's the main page [uq.edu.au] about the University of Queensland (Australia) Centre for Hypersonics program that is running this program. The BBC article mentioned is pulled from their press release. [uq.edu.au]

    First application for Mach 7+ won't be passenger travel, but military (if not already used) where it will not only be fast, but louder than heck - after all Jet Noise is the Sound of Freedom! ;-) [komar.org]

    • UQ has been working on SCRAM jets for the last 30 years. It's a black hole for research money and is driven entirely by who wants to do a post-graduate thesis in hypersonics at the time. Don't expect anything except more research out of their program.
    • by reporter ( 666905 ) on Sunday March 26, 2006 @05:52PM (#14999637) Homepage
      The circumference of the earth at its equator is about 25000 miles [lyberty.com]. A passenger jet traveling at mach 7 (about 5000 miles per hour) can circle the globe in about 5 hours.

      More to the point, the distance between San Francisco (in California, USA) and London (in England) is about 5000 miles [indo.com]. That same passenger jet at mach 7 can bring its passengers from London to San Francisco in about 1 hour. The trip would be much cheaper than that offered by a subsonic plane because 1 hour is only enough time for cheap snacks like airline peanuts and Coca-Cola whereas a 14-hour flight would mean an expensive (but low-quality) dinner tray.

      On the other hand, a 1-hour flight would facilitate global infidelity. An errant British businessman could fly to San Francisco, have dinner and sex with his squeeze, and then return to London within 4 hours.

      • That and your forgetting about the time differences.

        My favorite quote was from an US AirForce pilot of SR-71's. he Liked the SR-71 as he could have lunch in London, and land in time to have a late breakfast with his family in Los Anglos. That was Mach 3.

        All I have to say is that is some massive Jetlag one would have to deal with.
      • And then you get stuck in traffic, customs, and luggage claim for the 5 hours after your flight. We have the real-world version of Niven's "Long Shot" - a vehicle so fast that the setup/takedown time vastly exceeded it's useful travel time, so as such it was generally useless compared to a vehicle that went a tenth as fast.
      • Well, I hate to spoil the party, but we already have the technology for Mach 3+ flight (since, say, 1960: http://en.wikipedia.org/wiki/SR-71_Blackbird [wikipedia.org] and it's not like we've solved the problems with creating cost-efficient passenger versions of that yet.....

        I wouldn't be reserving those tickets for Mach 7 too soon, considering how much harder that's gonna be. Unless the return "go-one-mile-straight-up-and-then-slam-into-the-gr ound" trip appeals it a loooooong way off.

        Super fast maglevs will be first - bet
  • Dude! (Score:2, Insightful)

    by LazLong ( 757 )
    This was covered earlier!

    http://science.slashdot.org/article.pl?sid=06/03/2 3/2011251 [slashdot.org]
  • by cabinetsoft ( 923481 ) on Sunday March 26, 2006 @04:39PM (#14999394)
    The scientists had just six seconds to monitor its performance before the £1m engine crashed into the ground.
    'nuff said... just like my GF driving my car...
  • not new. (Score:5, Informative)

    by Kr3m3Puff ( 413047 ) * <`moc.ylleknostik' `ta' `em'> on Sunday March 26, 2006 @04:39PM (#14999398) Homepage Journal
    Scramjet's are a revolutionary "new" type of engine, they have just been difficult to get from the concept to pratical stage [wikipedia.org].

    The biggest problem is a way to compress enough oxygen at top speeds to feed the fuel reaction without needing to carry oxygen on board (which would be a rocket).
    • Rocket Engines (Score:3, Insightful)

      by suso ( 153703 ) *
      Scramjet's are a revolutionary "new" type of engine, they have just been difficult to get from the concept to pratical stage.

      From what I've seen in all those documentary films showing people testing rocket engines, they were also difficult to get from the concept to the pratical stage.

      New ideas bring new challenges.
      • I'll keep saying this every time scramjets come up.

        Scramjets are neither new nor really useful technology. Testbeds have been flying since the late 60's but the major problem with scramjets is that they are a very complicated solution to a very narrow problem. Decades of research have only shown that hypersonic combustion is extremely complicated & that more money is needed to "solve" the problem.

        First off, thay cannot begin functioning unassisted. They need rockets to get them up to hypersonic speeds s
        • Scramjets are neither new nor really useful technology And yet, When I was kid, ppl were talking about the impraticality or the impossiblity of going to the moon, or even building and flying a 747. And yet, we now see the 380 being built, with a very real possiblity that Boeing will create a good BWB that carries even more.

          The more knowledge that we gain, the sooner the use of it. I would guess that in my lifetime, we will find some very useable materials WRT to the skin.
  • by Anonymous Coward on Sunday March 26, 2006 @04:40PM (#14999405)
    " Scramjet (supersonic combustion ramjet) engines have no moving parts and take all of the oxygen they need (to burn hydrogen fuel) from the air, allowing for larger loads than rockets which must carry oxygen for fuel."

    What??? I'll sue right now. This infringes on the name for my patented propulsion "Spamjet" (tm) system.... a revolutionary aerospace technology by which vehicles set up Hotmail accounts, and then propel themselves across the world by converting the lengthening promises of penis spams into actual thrust.
  • ALL of the oxygen? (Score:5, Interesting)

    by thirdrock ( 460992 ) on Sunday March 26, 2006 @04:55PM (#14999449)
    Scramjet (supersonic combustion ramjet) engines have no moving parts and take all of the oxygen they need (to burn hydrogen fuel) from the air, allowing for larger loads than rockets which must carry oxygen for fuel.

    All jet engines take the oxygen they need from the air. Only rocket engines leaving the atmosphere require an onboard source of oxygen. Even the U2, which flew at > 40,000ft got it's oxygen from the surrounding air.

    And the Scramjet is a jet engine, not a rocket engine. The difference you were looking for is that scramjet engines do not require a turbine to compress the surrounding air. This allows the engine to move at a much faster speed because turbine engines have an upper speed limit before the stresses pull them apart.

    Also, theoretically if the compression was high enough the scramjet could burn jet fuel (kerosene) but there is probably technical difficulties with injection (ie. avoiding hot spots and detonation).
    • by Napoleon The Pig ( 228548 ) on Sunday March 26, 2006 @05:59PM (#14999661)
      I'm not even sure where to start with this one...

      1. Turbines in a jet engine are located after compression and combustion occur. Compression is due to compressors located after the inlet of the engine and before the combustion chamber where fuel is introduced and ignited. From the combustion chamber the high pressure, high temperature exhaust is then fed through the turbines which then generate power for quite a few different things including running the compressors.

      Engine Theroy: Suck, Squeeze, Bang, Blow.

      2. Jet engines do not work at very high speed not because of stresses in the compressors/turbines but rather because of the problems with supersonic flow. For supersonic aircraft the airflow into the engine is slowed to subsonic speeds using inlet geometry to control the oblique and normal shocks in the flow. Yes, theoretically you could spin the compressor faster than it's mechanical stress limits but that would occur a lot longer after the engine stopped working due to the flow.

      3. The reason hydrogen is used as fuel for the scramjet is because the pressure tolerances for the engine are extremely small. The compressed flow must maintain supersonic speed, contain enough heat to ignite the fuel, and have enough time to have initiation and reaction occur inside the combustion chamber before it's ejected out the exhaust nozzle.

      The reason they're comparing a Scramjet to a rocket engine is because having a Scramjet would dramatically reduce the weight of orbital flight by not having to carry its own oxidizer. For example: 75% of the weight of the Space Shuttle during launch is stored in LOX used as fuel.

      However the feasibility of using a Scramjet engine for a single stage to orbit vehicle poses problems of its own. Way too many to list here. But solutions might be found to these problems as technology increases.
      • Engine Theroy: Suck, Squeeze, Bang, Blow.

        ... a theory that also applies to Microsoft development and prostitution.

      • Soooo, a SCRAM jet doesn't suck?
      • great post. here's some more info.

        http://en.wikipedia.org/wiki/Scram_jet [wikipedia.org]
      • As over 75% of the shuttle's accelleration is exo-atmospheric where scramjets are useless, this is a good thing. Adding a poorly accelerating scramjet to the rockets needed for take-off + accelleration to scramjet speeds and the rockets needed to function outside the atmosphers only buys you a vehicle that will never attain orbit.
      • 2. Jet engines do not work at very high speed not because of stresses in the compressors/turbines but rather because of the problems with supersonic flow. For supersonic aircraft the airflow into the engine is slowed to subsonic speeds using inlet geometry to control the oblique and normal shocks in the flow. Yes, theoretically you could spin the compressor faster than its mechanical stress limits but that would occur a lot longer after the engine stopped working due to the flow.
        That's not right. Otherwise
      • Engine Theroy: Suck, Squeeze, Bang, Blow.

        Now, I don't know who this Theroy-girl is, but if she looks anything like Charlize Theron and that's her motto then, hell, just send her my way!
    • by agingell ( 931397 ) on Sunday March 26, 2006 @07:58PM (#14999997) Homepage
      FYI The record for air breathing aircraft (not rocket) is 85,068 feet, set in 1976 by a Lockheed SR-71 jet-powered aircraft. This was broken by the NASA helios solar powered (not air breathing) flying wing 96,500 feet in 2001
      Concorde was the highest flying commercial airliner with an operational ceiling of 60,000 feet.

      The SR-71(AKA blackbird had very specialised jet-engines which operated in a semi ramjet mode.

      The biggest problems with a scram-jet is trying to make it a scram-jet, i.e. the airflow through the engine has to remain supersonic. The shock wave angle decreases with mach speed, at low mach numbers it is too wide. This means that you have to have an impossibly large diameter and short engine to maintain supersonic flow. When you get hypersonic (above mach 5) the shock waves get much closer to parallel to the direction of motion, hence you can have a reasonable length and diameter on your engine. The length is the critical problem, as it is necessary to combust fuel and expand the working mass (air) within the engine in order that it can do any useful work. This is very difficult as mach 5 is 1701.45 m/s so if you have a 2m engine tube you have roughly 1.2 milliseconds in which to compress, burn and expand your fuel! The rate of flame propagation in kerosene is just not high enough to get even close at this kind of scale therefore hydrogen is realistically the only fuel which will work as it has the highest flame propagation rate, even hydrogen is difficult.

      Scram-jets are a very interesting technology, but there are others like air breathing rocket motors which use the liquid hydrogen to cool the intake air so that it can be compressed sufficiently to be fed into the rocket combustion chamber. This is a pretty good technique although the heat exchangers are pretty difficult to build. The have the advantage that you just bleed in more and more O2 as you leave the atmosphere until they are running in pure rocket mode.
      They do have the disadvantage that they can realistically only operate with a max velocity of about mach 5.5 when air-breathing as above that you get 0 net thrust and they are fairly complex. Air breathing rockets make single stage to orbit possible without ridiculous fuel to weight ratios.
    • Even the U2, which flew at > 40,000ft

      Try greater than 60,000 with a ceiling somewhere in the 70s.

      The SR-71 can fly 80,000+.

      There are even stories about towers giving clearance to 40,000 to SR-71, with the controller snidely stating, "it's yours...if you can get there." Whereby, the pilot replies back, "...affirmative...85,000 to 40,0000, followed by a nice chuckle."


      • There are even stories about towers giving clearance to 40,000 to SR-71, with the controller snidely stating, "it's yours...if you can get there."


        Kind of an odd thing to say when the ceiling on a 747 is about 12.5 miles or 65,000 feet.

  • by Silvers ( 196372 ) on Sunday March 26, 2006 @05:16PM (#14999521)
    Can anyone tell me why this engine is revolutionary? NASA has been testing these types of engine for some time.

    For example, the X-43 which hit mach 9.6.

    [url]http://www.nasa.gov/missions/research/x43-mai n.html%5B/url%5D [nasa.gov]
    • Actually on January 11, 1967 we launched a Castor/Scramjet on a test flight from Vandenberg AFB in California. This was the only test of this combination, followed years later by the NASA X-43 project.
      • Heck, when I was in junior high, (late 60's) I built the Estes Space Transport, or whatever the heck they called it. In it's blurb sheet it talked about an air-breathing plane that shifted to scramjets after takeoff, launching a rocket upper stage once it got to speed. Of course the Estes thing just launched a little glider, while the main rocket came down on a chute.

        But they were talking scramjets back in the 60's.
        Then again, my older brother had a plastic model of the nuclear-powered bomber well before th
  • "recently" ???? , only on slashdot is four year old news "recent" ,sheesh !

    Peter Macinnis journeyed to Woomera to watch the July 2002 test of the University of Queensland's HyShot scramjet. He was lucky enough to watch history being made - the test was the world's first successful scramjet launch.

    http://www.abc.net.au/science/slab/hyshot/default . htm [abc.net.au]

  • Results: (Score:4, Funny)

    by OO7david ( 159677 ) on Sunday March 26, 2006 @05:23PM (#14999548) Homepage Journal
    I'll bet it was a smashing success [slashdot.org]
  • Mach 7? (Score:5, Funny)

    by Z1NG ( 953122 ) on Sunday March 26, 2006 @05:46PM (#14999611)
    Five blades is plenty for me. I want to keep my skin atleast.
  • Didnt NASA just do this recently?

    Still cool, but id not say its 'new'.
  • by DerekLyons ( 302214 ) <fairwater.gmail@com> on Sunday March 26, 2006 @07:33PM (#14999925) Homepage
    Scramjet (supersonic combustion ramjet) engines have no moving parts and take all of the oxygen they need (to burn hydrogen fuel) from the air, allowing for larger loads than rockets which must carry oxygen for fuel.
    Unhappily when you go from handwaving theory to practical application - they don't work all that well. You trade the weight of the fuel for the scramjet for the weight of the turboject to get the ramjet up to speed, and for the weight of the ramjet to get the scramjet up to speed... plus the fuel for both.

    Furthermore - a scramjet is nearly useless as the first stage of an orbital launcher, because it wants to cruise at a steady speed. An orbital launcher wants to be steadily accelerating. The weight of the rocket fuel saved is less of a penalty than the increase in mass needed for structural reinforcement and insulation. Further yet, rocket fuel is cheap in bulk, it would be nearly twenty times more expensive expensive to fill it with unleaded down at the local mini-mart, scram jet fuel is expensive, even in bulk. (And we haven't even gotten to billions of dollars needed to build the aerodynamic stage.)

    Scramjets are a solution looking for a problem, not an answer to any question.

    • Furthermore - a scramjet is nearly useless as the first stage of an orbital launcher, because it wants to cruise at a steady speed. An orbital launcher wants to be steadily accelerating.

      I'm no rocket scientist but I thought scramjets actually want to maintain a steady speed RELATIVE to the air density (i.e. in thinner air, it has to move faster).

      Sure, if it was going HORIZONTALLY it would optimally maintain the same speed, but wouldn't the decreasing air density as one moved up in the atmosphere naturally
    • by jd ( 1658 )
      ARLA - an alternative rocket launch assist system - uses a ramjet as the second "stage" (the first stage is given as a gas cannon, but a magnetic linear accelerator would work better for manned flight). They propose a rocket on top of the ramjet, but you could easily have a scramjet on the ramjet, then a rocket on top of that.

      You don't need turbines to get a ramjet to sufficient speed. A ramjet will operate at 400mph - well within the limits of a propeller engine (I believe the Rolls Royce Merlin could mana

    • by asuffield ( 111848 ) <asuffield@suffields.me.uk> on Monday March 27, 2006 @02:30AM (#15001087)
      Furthermore - a scramjet is nearly useless as the first stage of an orbital launcher, because it wants to cruise at a steady speed. An orbital launcher wants to be steadily accelerating.

      That's not really true - or at least, it's highly confusing. All jet engines are accelerating whenever they are not idling: they exert a force on the craft causing it to accelerate at a rate of the force exerted divided by the mass of the craft. The apparent acceleration of the craft is reduced by drag and gravity. An orbital launcher has two requirements: that it gain sufficient height to reduce drag to near-zero, and sufficient velocity to actually be in orbit. There's numerous paths that will get you there and few of them involve 'steady acceleration' - a conventional 'great big rocket' launcher has steady thrust, but apparent acceleration to a ground observer is constantly changing with height, since the effects of drag reduce at higher altitudes.

      A scramjet does not cruise at a steady speed. It runs at a fixed level of incoming air pressure. It has to run at that level because a scramjet does not contain moving parts to control the air flow. That means, as the surrounding air pressure decreases, the scramjet goes faster. It effectively operates at a fixed speed for a given altitude, and goes faster as you get higher. This is ideal for an orbital launcher.

      However: the first stage of an orbital launcher is the one that gets it off the ground. A scramjet is completely useless as the first stage because it doesn't do anything when you aren't moving.

      A scramjet path to orbit looks rather different to the old 'big rocket' system. You start with a conventional turbojet aircraft, which takes off and lands normally, using a horizontal path and wings. That's the first stage. You use it to climb to turbojet cruising altitude, and maybe accelerate to your maximum operating velocity (about mach 2 to mach 3). Then you fire a ramjet engine (or small rocket booster - this can be a solid rocket) to get you up to mach 5, which is the breakeven point for a scramjet. Then you fire the scramjet as the third stage, which carries you from mach 5 up to about mach 10 or 12, and most importantly, to near-orbital altitude.

      At this point, the orbital craft that was piggybacking you breaks away, and boosts to orbit on one of the conventional late-stage rocket engines, like those used by the shuttle once it has discarded all its booster engines and is in the final orbiter configuration. It's already nearly there, so it doesn't need much fuel. The conventional aircraft that got it up here descends again and lands under turbojets, just like every other jet craft; the orbital craft has its own crew and operates independently.

      The two advantages of this design are that it should be largely reusable (because you haven't discarded half the craft on the way up), and it requires significantly less total thrust to get up there. A 'big rocket' craft has to fight the force of gravity all the way up; an aircraft with wings is supported by aerodynamic lift, and merely has to accelerate. The disadvantages are that jet aircraft have more drag than rockets (but aircraft fly all the time; this isn't a fatal problem, it just reduces the advantage), and nobody knows how to build a useful scramjet aircraft yet (the X-43 testing craft just prove the scramjet concept, they aren't useful in their own right). Whether or not anybody can build such a craft that can lift a useful payload weight to orbit is unknown, but the theory says it should be possible.
  • I'm guessing that these things have engines that burn quite cleanly, but does anyone have a good handle on the environmental impact of zorching around at more than Mach 7?
    • The only way to get to mach 7 efficiently is to use an assisted ramjet with hydrogen fuel. From start to finish, everything is burning hydrogen and oxygen (producing water). As 80% of the atmosphere is nitrogen, you will get nitrates forming as well, which (in the presence of water) will then convert to a very dilute nitric acid. It'll add a little to the acid rain, but far and away less than conventional jet fuels and VASTLY less than ship fuels.

      (As ships spend most of their time in international waters, m

  • For passenger transport, doesn't a supersonic maglev running in an evacuated tunnel make more sense?

    Well, as much sense as any ridiculous method you can think of to keep the super-rich on their meeting schedule...

  • SssshhhhhJet? (Score:3, Insightful)

    by Doc Ruby ( 173196 ) on Sunday March 26, 2006 @09:35PM (#15000280) Homepage Journal
    Is anyone working on quiet jet (or other fast) engines? If we want "flyign sportscars", their quiet features are more important than any other except safety. Who wants to get caught up in the "sidestream noise pollution" wars of the mid-21st Century?
  • in concocting goofy company names.

    QinetiQ sounds like the fusion of Qbert and Compaq. They ought to move out to Silicon Valley, so they can rub shoulders with the guys from qoop [qoop.com]. Or perhaps New York would be better, given that pando [pando.com] makes their home there.

  • Maybe some experts here (about sc/ramjets) can answer a question that has always nagged me:

    If the ramjet has no moving parts, and the diagrams of its cross-section always make it look like a fairly symmetrical constriction, why does the exhaust propel the thing forward? I.e. why doesn't the ignited fuel and hot air expand equally from both ends of the thing, and cause it to go nowhere?

    Is it the asymmetry because of the direction of the ram air stream? Or is it because the fuel is lighted just aft o
    • (Warning, very handwaving explanation which most likely has technical inaccuracies but paints a basic picture.)

      Basically, a ramjet relies on the inertia of an existing flow of air into its inlet to provide compression. That air continues to move to the back of the engine, and usually after the combustion chamber there is an expansion nozzle which allows the heated exhaust air to essentially push the engine forward with more force than it is resisting the incoming airflow.

      As a result, for proper operation,
  • pointlless travel (Score:3, Interesting)

    by Anonymous Coward on Sunday March 26, 2006 @10:28PM (#15000437)
    Instead of getting people to consume more (faster) travel and burning up the ever decreasing oxygene of the atmosphere in the process, maybe the emphasis should be directed more on things like *reducing* the need for air travel? Just like instead of encouraging road travel, the opposite should be happening. Global warming, remember? Overly dependence on foreign oil etc?

    Besides, when there were problems with making the Concorde profitable that flew at a mere mach 2, how in the hell is it going to be possible to create an aircraft that would be stable enough on ground level to take off and land, and still be profitable? The quantum leaps the material science has to make to meet such needs are huge.
  • First off, there's a description and history on the wiki scramjet page [wikipedia.org] and here's a description of scramjet operation [wikipedia.org].

    IANARS (I Am Not A Rocket Scientist), but as I understand it, one of the problems in making a working scramjet is How do you go fast enough to compress the air enough to get it to warm up enough to reach combustion temperature?

    Questions:

    1. Why not heat the air before it gets to the combustion chamber?
    2. Why not heat the fuel (e.g. hydrogen) so that it is closer to combustion temperature?
    • Actually, the big problem is mixing.

      A ramjet slows the incoming air via a shock across the inlet (and the various reflections). A supersonic ramjet still has shocks, but they don't slow the incoming air enough to run the way a ramjet works (if they did, you'd lose a LOT of energy in the pressure drop across said shocks).

      If done right, you get your mixing properly, then you use shock heating to ignite your mixture, and extract the momentum with a nozzle on the engine exhaust.
    • Im guessing that hotter air and hotter fuel are less dense, so you loose thrust and efficiency.

      Also, scramjets are eventually going to operate in thinner sections of the atmosphere, so there isnt enough oxidier to perform the heating except at those high speeds/compression ratios.
  • It is hoped that the engine, designed by UK defense firm QinetiQ and capable of Mach 7.6, will pave the way for ultra fast, intercontinental air travel.

    But it won't. You seen the price of fuel these days? Boeing hasn't done research into hypersonic travel in years; every R&D penny they've got is going into fuel-efficient mach .84 cruisers. Maybe some giant Aussie aerospace firm will be interested...

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