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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".
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.
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.
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!
"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
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.
And this is the exact same thing as these spinning sound waves generated by these rockets?
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.
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!!!
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."
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!
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.
nothing to see here, this reply is just to remove an incorrect mod.
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.
5kHz isn't exactly low frequency sound
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.
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!
What uses 0.2hz waves for acoustic communication? Even an elephant on sulfur hexafluoride doesn't get that low.
And so the old question foes, "If a tree falls in the forest and there is no one there to hear it, does it make a noise?
Well by the definition of sound there are three components:
Hence the phrase, "In space no one can hear you scream.". Now that was a movie, but it is never the less true. We have all seen the experiment where you take an electric bell, place it in a vacuum chamber. As the air is pumped out the, softer the sound of the bell gets until it can no longer be heard.
No medium, no pressure wave, it's that simple. Now there is liquid fuel in pipes, that is being pushed hard into the combustion chamber by pumps. Ever seen what happens to a jet engine during a compressor stall? The high pressure exhaust comes out he front! YIKES, not a good thing at all. Now those pumps are pushing the liquid fuel and oxidizer into the combustion chamber against combustion pressure. The ONLY thing preventing the combusting fuel and oxidizer mix from going right back UP those pipes and making the whole damn thing blow up are the pumps. I would imagine that all sorts of pressure waves are transmitted back up into the inner working of the rocked via the medium of the fuel. Imagine if the pump "stalled" ie the pump vanes out paced the fuel supply? The pump impellers would effectively stall and pressure in the delivery lines to the combustion chamber would drop and allow back flow until the pump caught up and started pushing fuel again, I think this would definitely cause some pressure waves all over the place. It would also cause lots of vibration, perhaps enough to cause failure,
Hey KID! Yeah you, get the fuck off my lawn!
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.
What they need is an Oddball at launches to demand people stop sending out "negative waves".
Take Nobody's Word For It.
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.
If the waves reach the ear drum and are interpreted, would they become sound? Sound is vibration through a medium that is perceived by something. If I make waves in a jump rope at the right frequency, I'm pretty sure I can hear it. Just because the device (human ear) isn't sensitive enough to detect it doesn't mean it isn't sound.
Layne
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!
If you are an English major and a tree falls in the forest and there is no one there to hear it, there is no sound.
Physicists define sound as compression waves traveling through a medium, like air. So a Physicist does not need an observer for the sound to exist. as long as the falling tree starts a series of compression waves in the compressible media around it (air, water, ground) there is sound.
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.
Dictionary.com says the definition of "sound": Def. 2. mechanical vibrations transmitted through an elastic medium, traveling in air at a speed of approximately 1087 ft. (331 m) per second at sea level. Merriam-Webster, "sound": 1.c. mechanical radiant energy that is transmitted by longitudinal pressure waves in a material medium (as air) and is the objective cause of hearing OK, then what about the word "noise":
Dictionary.com again, "noise": Def. 2. a sound of any kind Merriam-Webster, "noise":
Hmmm... the closest definition is: 2.b. any sound that is undesired or interferes with one's hearing of something So, no mention of a detector other than only on the Merriam-Webster definition of "noise" might a detector be needed.... although that is subjective on whether you desire the sound of a tree falling. Otherwise, a "detector" is not necessary for sound to exist. Plainly, it is nothing more than vibration. Since it would seem impossible for a tree to fall without making vibrations, it *must* make a sound. Does it make a noise? That is dependent on your subjectiveness of the sound it makes at worst.
Yes, I am being nitpicky.
"They said I probly shouldn't fly with just one eye," "I am Bender. Please insert girder."
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.
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.
Not so sure of that....
Since what I know about I learned in both physics class and in the US Navy when I undertook SONAR training.
I will agree that a pressure wave is a pressure wave, but does light make a sound? Depending on your POV it is either a wave or a particle, So if in the examination of light, if one considers it as a wave with a compression and rarifraction, a given frequency if you will, either as visible light or in the ultraviolet, visible or infrared spectrum, is it therefor a sound as well, or simply a pressure wave, or is it, as it has been commonly named in agreement for lo these many years, just light?
I would think that "sound" is an organic principle since only organic beings, at least as far as I know, are the only things that can perceive it as such, because we have a sensor tat will translate those pressure waves into an electrical impulse that is then perceived by an organic processor, namely the brain.
Suppose one sets up a transducer that has the capability of detecting, say the ultraviolet spectrum and then displays that spectrum on an oscilloscope. There is a medium, there must be even if light is traveling through space, their must be a source as the light exists and is detectable, it is perceived by the transducer and is shown to exist on the oscilloscope, but is it sound?
I can only conclude that is must not be, but I could be wrong.
I therefor conclude, that sound cannot exist, without an appropriate receiver that classifies it, as sound.
Dubito, ergo cogito, ergo sum
Hey KID! Yeah you, get the fuck off my lawn!