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Mysterious Sound Waves Can Destroy Rockets
Ponca City, We love you writes "Scientists believe that powerful and unstable sound waves, created by energy supplied by the combustion process, were the cause of rocket failures in several US and Russian rockets. They have also observed these mysterious oscillations in other propulsion and power-generating systems such as missiles and gas turbines. Now, researchers at the Georgia Institute of Technology have developed a liquid rocket engine simulator and imaging techniques to help demystify the cause of these explosive sound waves and bring scientists a little closer to being able to understand and prevent them. The team was able to clearly demonstrate that the phenomenon manifests itself in the form of spinning acoustic waves that gain destructive power as they rotate around the rocket's combustion chamber at a rate of 5,000 revolutions per second. Researchers developed a low-pressure combustor to simulate larger rocket engines then used a very-high-speed camera with fiber optic probes to observe the formation and behavior of excited spinning sound waves within the engine. 'This is a very troublesome phenomenon in rockets,' said Professor Ben Zinn. 'These spinning acoustic oscillations destroy engines without anyone fully understanding how these waves are formed. Visualizing this phenomenon brings us a step closer to understanding it.'"
It makes rocket scientists crap their pants!
This means rocket science is once again hard. You may now resume saying "Well, this isn't rocket science" until they solve this.
jX [ Make everything as simple as possible, but no simpler. - Einstein ]
and the subject line for this article has finally convinced me that cowboy neal is in fact art bell.
Is that a rocket in your pocket? Finally I could satisfy a woman! :(
I wonder if they'd be interested in analyzing the smoking ruins of at least 5 toilet bowls I have personally destroyed with mysterious oscillating rocket powered sound waves.
Fascism trolls keeping me up every night. When I starts a preachin', he HITS ME WITH HIS REICH!
When analyzing the acoustic oscillations scientists discovered something quite striking. The sine wave was exactly identical to the master recording of Britney Spears' "Hit Me Baby One More Time".
The Tacoma Narrows Bridge http://www.youtube.com/watch?v=AsCBK-fRNRk was essentially destroyed by low frequency sound waves.
Engineering is the art of compromise.
Could be implemented in a way to defend against rocket\missle attacks? Possibly in a better way than Star Wars program.
Trying to install linux on my microwave, but keep getting a kernel panic...
If you record them and play them backwards they will install Vista on your computer.
The Captain has known since 1986 that sound waves, particularly the very potent tones of Jimi at Berkeley, can destroy oncoming rockets.
Reference: Riders of the Storm
Dr No will fish them out of the water and pass the rockets on to SMERSH....I don't like the sound of that!
Between the falling angel and the rising ape
I remember reading about Nikola Tesla using sound waves to demolish a building or something like that.
Wow, he invented Britney Spears also?
Table-ized A.I.
The new result here isn't acoustic instabilities; those have been known for a long time. The interesting result is a new set of imaging techniques that give a better understanding of *why* they occur, rather than simply observing on pressure traces that they *do* occur. After a bit more research, this may turn into techniques to more reliably avoid them in the design stage, rather than having to go through various tweaks on the injector / combustion chamber to remove them should they appear.
This is very cool work. Of course, it's rocket science, not rocket engineering, so it's unlikely to impact new designs for several years yet.
House Atreides was not available for comment.
"The price good men pay for indifference to public affairs is to be ruled by evil men." ~Plato (427-347 BC)
Come on, an expert on rocket fuel technology named Professor Ben Zinn?
I can't help but wonder if understanding this won't lead to some powerful weapons... think about it a sonic cannon, that might make some interesting CNN coverage during war time.
well hey, thanks for posting. something you might have heard about somewhere about a subject you very likely have no knowledge about whatsoever. i can guess that by the complete lack of anything useful in your post. let me go way out on a limb here and guess that your age is 14 years or less. 15 tops. in the future, be useful or silent. thanks!
I bet given enough strength, your fart can break the toilet too.
"The New Age. The New Beginning."
So is gangsta rap going to be the new missile defense? Instead of dedicated stations, we could have a volunteer rapid response unit consisting of Honda Civics.
Rocket-cons inferior...
~ Old Warriors Society
*Blank stare* - "These go to eleven."
Light the blue touch-paper and retire immediately.
Should read:
and bring scientists a little closer to being able to understand and generate them.
I wonder if these sound waves might be put to good use... such as setting off a series of timed explosions creating a "traveling wave" that induces rotation... This might come in real handy if, say, the core of the earth were to stop spinning for some reason... hmmmm... oh crap, this justifies a terrible movie.
They told us
All they wanted
Was a sound that could kill someone
From a distance.
Instead, it killed the rockets!
Heavy Metal can destroy even rockets now.
Rocket engines typically have a round cross section, which, if it doesn't aid the production of these circular waves, probably does little to dampen them. I wonder if the "inside out" design of a linear aerospike engine suffers from the same problem.
When our name is on the back of your car, we're behind you all the way!
Sim-harmon-mosh :) You had to be there around '93 to get it.
"The fight for freedom has only just begun." - Geert Wilders
...will the Civics play Soulja Boy, and will "Superman that" be slang for attacking an incoming warhead?
You can hold down the "B" button for continuous firing.
For crying out loud (sorry;) we are talking ROCKET SCIENCE HERE!!!!
sig sig sig siggy sig
Yeah, yeah, we've been through this before. Dr. No, evil genius with his own Caribbean island, guano empire. Bond on the beach with Honey Rider, bang-boom, no more "interference" with our rockets. Guess we throw the Russkies a bone on this one, in the name of our newfound cooperation.
This phenomenon sounds very similar to Pogo Oscillations, which incidentally caused the engine 5 shutdown on the Apollo 13 Saturn V.
http://en.wikipedia.org/wiki/Pogo_oscillations
Could this exploding power be used to generate power?
The summary makes it sound like this is a new and mysterious phenomenon. It isn't.
Resonant frequencies inside the fuel pumps and associated plumbing is one of the major problems of getting a real rocket engine run in a stable cycle. This is a 50-year-old problem. There are also 50-year-old solutions, mostly involving re-shaping the plumbing so that resonances are dampened.
See also Pogo oscillation and the famous case of Apollo 13.
Doesn't everything have a frequency at which it breaks? I mean, human rib cages, crystal glasses have been known to break with just the right tone. In the case of a former engine of mine (non-rocket), it was right around 133Hz (8000rpm/60seconds=133 Cycles per second).
The game.
While the power of standing waves is well-documented, (see the aforementioned Tacoma Narrows Bridge) this story is commonly considered to be an urban legend, as far as I can tell. They did try it on Mythbusters, though. There were issues with Tesla's designs, so they were forced to build their own. While they were unable to even slightly harm a small-scale model, they did have some success making an actual suspension bridge vibrate. Still, vibration is far from destruction; while much damage to buildings during earthquakes is due to standing waves, in those cases we are talking about faarrrr greater amounts of energy than Tesla's oscillator.
Fear the penguin.
I can now revive my hopes having a wierding module...and that my name will be a killing a word!
This is amazing. It's incredible how the accoustics of a barrel can make the physical state of a metal to something that's entirely unknown because it is being bombarded with such energy that it is entirely unknown. The heat radiation that it gives off, as well as the amount of energy released as light, those waves are just bouncing off. Of course, I surely don't mean that it may be a complete possibility, but we simply don't know. What if a total chaotic environment throws off the marks of physics once more to a completely different level, the sound spectrum, the beyond. String theory is portrayed as strings or strands of energy in acoustic resonance with itself, or not, some are broken, making some sounds as neutral. Maybe I'm getting off track here. Whatever, this is all new, so let's begin!
I know, its the sound village ninjas from Naruto upto their old tricks again!!!
The point of Tesla's experiments were that you didn't need a huge amount of force, just a small force at just the right frequency for the particular object. The small oscillations would reinforce the previous ones and grow into a more powerful force that eventually cause collapse... Even mythbusters gave this a plausible.
Looks like an audio engineering issue. While not being a rocket engineer myself, I assume the combustion chamber is somewhat symmetrical. It is likely acting as a resonance chamber and increasing the amplitude of the soundwave to the point of physical damage. I shattered the rear window in my '96 Camaro twice with a 1200W Fosgate and a single 10" bazooka tube. Tell NASA to crack the window when they turn up the bass!
Perhaps this knowledge can be used to build an anti-rocket defense system.
McCain/Palin '08. Now THAT's hope and change!
So THAT'S how the Doctor's screwdriver works...
Of course. I never denied the theory behind it, and I do know they listed it as plausible (see "some success making an actual suspension bridge vibrate"). My point is simply that Tesla didn't actually destroy a building. He simply showed that it is theoretically possible.
Fear the penguin.
http://www.rastko.org.yu/rastko/delo/10896
[Nikola Tesla:] "I was experimenting with vibrations. I had one of my machines going and I wanted to see if I could get it in tune with the vibration of the building. I put it up notch after notch. There was a peculiar cracking sound.
"I asked my assistants where did the sound come from. They did not know. I put the machine up a few more notches. There was a louder cracking sound. I knew I was approaching the vibration of the steel building. I pushed the machine a little higher.
"Suddenly all the heavy machinery in the place was flying around. I grabbed a hammer and broke the machine. The building would have been down about our ears in another few minutes. Outside in the street there was pandemonium. The police and ambulances arrived. I told my assistants to say nothing. We told the police it must have been an earthquake. That's all they ever knew about it."
Watch Out, Mr. Smith
Some shrewd reporter asked Dr. Tesla at this point what he would need to destroy the Empire State Building and the doctor replied: - "Five pounds of air pressure. If I attached the proper oscillating machine on a girder that is all the force I would need, five pounds. Vibration will do anything.- It would only be necessary to step up the vibrations of the machine to fit the natural vibration of the building and the building would come crashing down. That's why soldiers always break step crossing a bridge."
Whenever my x-girlfriend started singing, it would destroy my rocket, she had a voice like a crow. Wait, that isn't what we're talking about is it?
Houston, ...(beep)...
Whats the story on the center engine cutoff??
It can surely destroy those loud bass hipsters right? xkcd:bass
All you've got to do is to wrap the rocket in sound deadening materials - or negate the sounds by amplifying the same sound out of phase.
What's so hard about that?
Rocket science.... Hrumph!
Don't be apathetic. Procrastinate!
We Fremem have known the secret Bene Gesserit ways of harnessing destructive sound waves for centuries.
"My own name is a killing word. Will it be a healing word as well?" - Paul "Maud'Dib" Atreides
These killer sound waves come in really handy when some obese Harkonnen swine tries to make off with YOUR spice!
Four throats. Very powerful.
If my call is important, why am I talking to a recording?
"excited spinning sound waves" sounds like something which will be sold next year to the owner of the car ahead of us.
Honest question. Isn't sound merely an organic perception of certain frequencies of vibration? Talking about sound waves seems to only make sense in the context that it affects the ear. I assume these rockets broke apart due to intense vibration, not the particular noise that was being made.
Combustion instability is an old problem with rocket engines. The Saturn V main engine had serious combustion instability problems, which were fixed by trial and error testing. The Apollo booster people had to resort to setting off small bombs inside engines on test stands to induce instability, then trying different patterns of holes in the plates the distributed fuel to find a stable configuration.
The SR-71 engine had serious combustion instability. That, too, was fixed with something of a hack, an automated "sympathetic unstart" system which, when one engine had a stall, would stall the other one, then restart both.
Better simulation tools in that area can't hurt. Not many big supersonic engines are designed any more. As Scott Crossfield pointed out just before he died a few years ago, every aircraft that went significantly over Mach 3 is now in a museum.
Talking of rockets and waves, I was at the launch pad at the Baikonur cosmodrome on Tuesday and our crew almost got arrested for using Motorola walkie-talkies. They told us we had been interfering with telemetric systems and the live TV feed from the rocket.
Farting in an enclosed area under a quilt will result in the almost immediate destruction of any relationship.
Yeah, my karma sucks....but so do the mods.
Ok, before parent gets any farther this has to be de-bunked. Sound waves did not destroy the bridge. A sound wave, in any medium consists of a compression and a rarifraction ., that is a leading pressure wave followed by a area of lower pressure that propagate in a known fashion. The intensity of a sound wave obeys the inverse square law.
What happened to the Tacoma Narrows Bride was caused be an error in aerodynamic calculations on the part of the design engineer. Air passing around the bridge deck acted exactly like air does when presented with a crude airfoil, it formed an area of low pressure leeward of the bridge deck and a low pressure area leeward and below the bridge deck. Th resulting high pressure and low pressure vectors imparted a twisting moment to the bridge deck.
The twisting moment was resisted by the torsional rigidity of the bridge deck. This caused the deck to twist to and build torsional tension. The twisting caused the aerodynamic profile of the bridge deck to change. The resulting change allowed the bridge deck to revert back to its original shape and aerodynamic profile, rinse and repeat. Thus the repeated twisting caused enough of the riveted and bolted joints to fail which led to a cascade failure as the remaining joints failed under the bridges weight and twisting motion.
This was not "low frequency sound waves" although the structures oscillations did cause some very low frequency sounds waves, it was destroyed by nothing more then bad aerodynamics.
Hey KID! Yeah you, get the fuck off my lawn!
"Mysterious sound waves" like years of speeches by a lying president who cancels NASA programs, lies about a Mars mission, and instead converts NASA to Star Wars "missile defense"?
--
make install -not war
Those weren't sound waves. Waves on a jumprope aren't sound waves and neither were those on Tacoma Narrows Bridge.
This racetrack instability is actually a well known problem with annular combustion chambers such as those used with the toroidal aerospike engine. One of the main virtues of vortex engines, like Orbital Technologies or the ultracentrifugal one invented by Roger Gregory and myself, is that the coriolis effect distorts the wave front sending it into the wall of the combustion chamber. In theory, at least, this should disrupt the resonance enough to prevent destructive standing waves. Experiments have not been conducted to test this theory yet to the best of my knowledge.
Seastead this.
Emanates from 'American Idol' and the mouths of annoying redneck singers Miley Cyrus and Jessica Simpson.
This has been a problem since the start of rockets. When I used to make them in the 1980's and 90's, we used to call it a ballistic or acoustic "anomaly". Shows how much we knew by how we characterized it. All we knew was that is was rocket design-specific and had something to do with the internal physical configuration and burn profile. We also knew it could be a sure death to a program since there were no known ways to eliminate it. (Although I think some used anti-resonance rods in the old days.) Trial and error sometimes worked, but that's how all rocket motors are developed to some extent! Sometimes your lucky; sometime not.
What they need is an Oddball at launches to demand people stop sending out "negative waves".
Take Nobody's Word For It.
The Cosmic Fart.
or
Moby Dick (as in 'Thar she blows!')
Sonic Screwdriver? I THINK SO!
For you see, I am a professional acoustician, and now I have PROOF that playing with sound IS rocket science!
Browsing at +1 - no ACs, I ignore their posts. So refreshing!
wobbly bridge
And did you exchange a walk on part in the war for a lead role in a cage? - Pink Floyd.
I'm not a rocket scientist, but I think they call it harmonic oscillation. Everything has a resonant frequency, hit it and it will "blow up". Think of the glass shattering in the Memorex commercials.
Living in Florida, I have seen the Shuttle launch a few times in person.
From about 7 miles away, that thing literally "shakes the sky".
I also like auto racing. The Gatornationals are drag races which include those Nitrous burning funny cars and dragsters. You can get 20 feet away from them down by the fence when they launch. Now those things do not just "shake the sky" --- THE SHAKE YOU. It feels like the dang time-space continuum is being warped and you are too. It is absolutely worth the price of admission (bring earplugs).
So those sound waves getting destructive really are a serious issue!
- I live the greatest adventure anyone could possibly desire. - Tosk the Hunted
Reading this story and the linked article at Georgia Tech made me flash back about 10 years to when I first discovered Slashdot.
Great article, classic Slashdot!
I know TFA is about the imaging technique using a simulator... but now that they can analyze the problem... why not see it as a happy accident and attempt to harness the energy that is causing the problems?
Maybe in addition to finding a way to stop the pressure waves they should also be looking for a way to enhance them and direct them... preferably in a way that creates additional propulsion or possibly a standing wave of some sort.... would be really cool if this led to a method of hovering... the military would love that, rockets that could station keep in mid-air waiting for the right time to strike.
For the rest of us, speeder bikes here we come, w00t
A fool throws a stone into a well and a thousand sages can not remove it.
Oh look! It's a rocket!
.... stupid rocket.
BRRREEAAAAAAK!!!!!!!!!! JYNX!!!!!!! heh heh
My favorite pass time is recording records, remember them?, that would break my friend's latest hifi record player.
I'm probably not the only one who realizes what this means: we can defend ourselves against nuclear war with the power of ROCK AND ROLL!
Sonic Disruptors next?
Or, can we mount it on a Humvee, and call it mass extraordinary interrogation?
I am the unwilling control for my Origin.
Sounds like these oscillations if harnessed for good could increase the thrust of engines.
As a graduate student studying acoustics, i'm surprised that this is a new discovery. They're pumping a lot of energy into a cylindrical cavity and getting azimuthal modes. Maybe its a poorly written article and the point is not the waves but the modeling techniques. Either way, i was under the impression that GA Tech has some knowledgeable professors doing research in acoustics. I hope that they're yelling at the rocket scientists for this publication.
Seems from what's known about it now, it's destructive. But if better understood, what's to keep engineers from making it actually do something useful? Might be a way to design a resonance chamber to pump fuel or something like that.
Also understanding the phenomenon in more detail is likely to help designers of ramjets and valveless pulse jets. I'd even take a guess that the latter depends on this phenomena to actually work in the first place.
If you propagate and direct them outside of the missile, you get a stripe of sonic destruction! :]
Is the problem simply that waves of a certain frequency reinforce when bouncing back and forth between the walls of the rocket engine? Art Garfunkle and former president James Taylor had a similar problem while recording. They installed some bass traps in the corners and made sure there were no parallel surfaces ... But I'm sure you Slashdotters could care less about our resort town ways.
... also, I can kill you with my brain.
Just to make it funny again.
The RIAA has initiated court action against the US Department of Defense for unauthorised reproduction of a copyrighted work...
I am government man, come from the government. The government has sent me. -- G.I.R.
... After changing your trousers, of course.