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Cloaking Technology Could Protect Offshore Rigs From Destructive Waves
cylonlover writes "Recent years have seen much progress in the development of invisibility cloaks which bend light around an object so it can't be seen, but can the same principles be applied to ocean waves that are strong enough to smash steel and concrete? That's the aim of Reza Alam's underwater 'invisibility cloak.' The assistant professor of mechanical engineering at the University of California, Berkeley, recently outlined how to use variations of density in ocean water to cloak floating objects from dangerous surface waves."
Will need lotsa beer to significantly change the seawater density around the platform.
Just sayin'
Questions raise, answers kill. Raise questions to stay alive.
Aha. Care to share your credentials in fluid dynamics with the rest of the class Mr AC...?
I, however, do know about oceanography. And I know that calling the technology a "cloak" is a joke, it's simply interference. I haven't even taken Physics III and I understand the principles behind the technology. A typical rig has water velocity sensors looking horizontally outward close to the surface and downward on the drillin' axis. Such a "cloak" would be pointless because the rig is pragmatically a fixed structure and bad conditions above are the same as bad conditions below. In short, if shit too wild, either up top or down below, you ain't drillin'. If existing patterns of surface waves were that dangerous to rigs, nobody would be rigging.
Prove me wrong.
-- Ethanol-fueled
Fair nuff. But are there wave-based 'storms' well below the surface anyway? Apart from regular ocean currents, I thought I read that once you get a few metres down it's all status quo. Certainly as far as temperatures are concerned, which don't vary by more than 3 degrees or so once you get 3 or more metres under the surface, same depth vs depth, all the way from the equator to the poles. But what I read may have been full of shit.
I am perpetually impressed by how useful mathematics derived from a few abstract axioms can actually be in modelling the real world. Further, it is always fascinating to see the strange overlaps where a single mathematical abstraction proves useful in the examination of two seemingly unrelated phenomena...
It is apparently so; but the idea that waves made of seawater and 'waves' that function as models of certain aspects of the behavior of electromagnetic radiation is always deeply surprising.
Someone getting an early jump on April 1st?
Did they get this cloaking technology from the Romulans?
It appears that the 'cloaking device' would create impulses in the water that would null out at least part of the big nasty surface wave. To do this, it has to be coupled to the surface - otherwise no energy would get imparted.
The physics of wave amplification and cancellation are well established. I imagine that we have the technology to look at the waves coming at the rig, figure out the waveforms and come up with 'counter' waveforms. I'm having problems, however, figuring out where he is going to get the energy to make the counter waves.
And for once, I have to agree with EF, it doesn't appear to be work like other cloaking' devices (where the waves are bent around the object), it just seems to be waveform cancellation. Of course the TFA has little in the way of useful info....
Faster! Faster! Faster would be better!
The last one I saw was this: http://www.newscientist.com/article/dn14829
and: http://discovermagazine.com/2012/jul-aug/06-how-to-make-anything-disappear
I'm having problems, however, figuring out where he is going to get the energy to make the counter waves.
Energy, oil companies? Not a problem. Do you know how much energy it takes to pull a several miles drill string out of the ground when comes the time to change the drill bit? Hint: the hook that grabs the string is 15 to 25 tons on triple rigs (they stack 3 pipes on the derrick when pulling out, to make things go faster).
Now, do you know how much energy it takes to drive and the size of the pumps that push drilll fluid inside the drill string ?
In order of magnitude, cost efficiently speaking, I think it would be feasible.
Everything I write is lies, read between the lines.
Furthermore, once the hole(s) in production, just use the natural gas coming out to power the "cloaking" device instead of burning it. That's the big flame you see on production platforms. They just waste it because it is to risky and not efficient (money wise) to store.
Hell, on production platforms where not much natural gas comes out, just use crude oil. Some super tanker boats run on crude oil so energy sources do not seem like a show stopper anyway.
Everything I write is lies, read between the lines.
Does this invisibility cloak make me look fat?
I was promised a flying car. Where is my flying car?
Nothing a few caterpillar generators can't do. Platforms have more than that available, they could just stop drilling and divert the power to counter-measures. :
http://slashdot.org/comments.pl?sid=3268803&cid=42071527
http://www.google.ca/url?sa=t&rct=j&q=how+many+MW+on+a+diesel+elecric+drill+rig&source=web&cd=8&ved=0CHcQFjAH&url=http%3A%2F%2Fwww.cat.com%2Fcda%2Ffiles%2F3072695%2F7%2FGP11PR6.docx&ei=YievULnYJOrg0gGSkoHACw&usg=AFQjCNEn8gYamAjnWDX7SF9lpTpqpFljpw
Everything I write is lies, read between the lines.
No credentials other than 5 years of sea duty with the US Navy. A few months of that time were spent on "rough seas". At least a month of that were on seas that came close to those described in "The Perfect Storm" - often exceeding 60 feet, and at times exceeding 80 feet. No hundred foot seas for me, 80 was enough.
Now - are you ready for it?
Neither the waves nor the swells are very random. I don't believe that anyone can predict them with very much accuracy, as of now, but they are generally predictable. Chop is another matter, entirely. If there is any way to predict chop, I can't imagine what it is. But, chop has very little energy, and has almost zero effect on the stability of a ship, or any other large platform.
I highly doubt the effectiveness of this cloaking device, but if it is somehow capable of mitigating some of the water's force, then we can and will develop the software to better predict the actions of swells and waves.
That said - I don't believe any software will be able to take rogues into account. They are named rogues, because they run counter to prevailing seas, seemingly at random.
"Windows is like the faint smell of piss in a subway: it's there, and there's nothing you can do about it." - Charlie Br
Sea conditions are felt more than a "few meters down". Anecdotal evidence suggests that a storm's actions can be felt at 500 feet, and really severe storms even further. I've never been underway in a sub, so I have no firsthand knowledge. Bubble heads will tell you that they dive when the seas are rough. The rougher the seas, the deeper they want to dive.
I don't think any storms are likely to be felt past 500 meters, or yards.
"Windows is like the faint smell of piss in a subway: it's there, and there's nothing you can do about it." - Charlie Br
Good point, I never said that kind of energy was required. I just wrote that it was available to oil platforms ;-)
http://slashdot.org/comments.pl?sid=3268803&cid=42071753
Everything I write is lies, read between the lines.
Well, it would probably just do as much good.
This sig no verb.
As I understand, to generate that cloak you need to create/modify underwater layers by changing salinity or temperature or direction. It all comes down to manipulating HUGE masses of water -- meaning investing HUGE amounts or energy. It's a cool idea but the implementation is in the regions of sci-fi.
Oil rigs are pretty good at exploding on their own without huge waves. we need something to cloak the ocean (and the atmosphere) from from the effects of oil rigs. soviet russia you're our only hope.
TFA states that no, they won't be creating impulses in the water. Instead, they noticed that
a. waves can travel on the surface, or at the thermocline.
b. waves interact with and can be influenced by the seafloor.
They propose to shape the seafloor so that the waves move from the surface to the thermocline. This means the wave is no longer visible at the sea surface.
As I understand, to generate that cloak you need to create/modify underwater layers by changing salinity or temperature or direction.
You misunderstand:
He found that by placing a corrugated or wavy pattern tuned to particular wavelength on the seabed it would cause surface waves to temporarily become internal waves.
The two layers of water are a natural phenomenon which allow the waves to be transferred underwater.
systemd is Roko's Basilisk.
Those ocean researchers should really check whether Sandy Island is not actually covered in an invisibility cloak.
I have not RTFA because that's how it is but there's another fine way to change the density of water, you inject air. They can store air pressure in a weighted cylinder, water columns... etc etc
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
The soon to be over used buzz word of 2013..
---- Booth was a patriot ----
While the technology might have the same basis as these cloaking efforts, this should more properly be described as "shields".
http://alternatives.rzero.com/
He found that by placing a corrugated or wavy pattern tuned to particular wavelength on the seabed it would cause surface waves to temporarily become internal waves.
The two layers of water are a natural phenomenon which allow the waves to be transferred underwater.
"Tuned to particular wavelength..." how is that a natural phenomenon?
then they won't smash against it? They'll just pass right through, because the rig is, umm, invisible?
They should apply it to cloaking cars. Then there'll be no accidents. Very practical.
Long, long ago when I was young, I used to read adventure tales.
All those that happened at sea had the mandatory storm scene of course -- and each time, classically, the pirate captain (or whatever novel hero) suddenly decided to drop oil on the terrible sea, which by this way turned way cooler.
Mind you, I even tried this myself!
Now, of course, you need, and will waste, oil. I understand it's not fashion nowadays...
Herve S.
Not single pure damping frequency of circular ripples on ocean floor as depicted in simple diagram. Ogg say using single frequency like silly noise cancellation experiment where complex wave beat at edges of cancelling cone to make frog whisper artifact or low frequency beat that make heavy furniture walk around room and make dust bunny dance.
Ogg say use simulation to find most potentially harmful frequencies to oil platform and plot bell curve around them and make concentric patterns of bumps on sea floor not simple ripple, the bumps' separation along radius correspond to harmonics of range of harm frequency. Ogg say put shallower bumps with wider separation around outer edge of sea floor and dense but high bumps immediate surround oil rig and under it.
Because Ogg say only fool want to cancel single favorite wave frequency because nature love to laugh at fool who do so, nature just whistles off key and the fool's brick house go down and fall on piggies inside. Nature love to generate wave with fundamental logarithmic base off by tiny fraction to drown Egyptian surveyors whose brains full of cubits loving of whole numbers.
But Ogg ashamed because in place of egghead math smart magic that will not work Ogg use maths to introduce Gaussian harmonic and what is more Gaussian than a bunch of rocks so Ogg back to rocks again, yes pile a bunch of irregularly shaped rocks on ocean floor just like do on surface by peoples who have no need for maths because they just know to pile up rocks to resist the ocean. Rocks different shape they know Gaussian distribution better than Ogg.
Rocks really smart. Ogg say, rocks rock.
<blink>down the rabbit hole</blink>
Music tends to produce a pretty random array of waves, yet I've seen active acoustic stuff (bass traps) in studios that fixed all the deleterious waves that would ruin the recording. Same principles at work, methinks.
Maths FTW!
They feared that it could be used to suppress protest or support unpopular rule.
The diesel electric rig I used to work on had indeed 10 of them and it was a plain on land rig. That rig wasn't the biggest either. Bigger = able to go deeper.
Also, as another poster as noted, if you read TFA, that kind of power might not be needed at all. The "cloaking" device would be installed at the bottom of the ocean and it is not clear how much power it would require if any...
Everything I write is lies, read between the lines.
I know the pics show the device on the bottom but seemingly that would work only for shallow water rigs and not for the deeper platforms. Still would need large amounts of power (I guess). And dealing with a 100 MW power plant (or the output of same) on the bottom of the ocean is a pretty big engineering challenge.
Nice to have some real numbers and a better diagram.....
Faster! Faster! Faster would be better!
As typically happens here on Slashdot, most of the comments deliberately ignore the technical content and make bad irrelevant jokes and/or trash the researcher for being stupid. The person who wrote the original paper is clearly a very intelligent and accomplished academic and doesn't rate this kind of mindless attack. You don't get on the faculty at UC Berkeley by being less then competent.
The "cloaking" description was clearly written by the semi-literate incompetent hack who wrote the fluff piece that quoted the original research. They were trying to tie this research into the recent publicity on electromagnetic cloaking with microwaves and did a very bad job. Any criticism or analysis based on the idea of cloaking is obviously bogus and irrelevant.
From what I could glean from the garbled information, this technique is applicable for the conditions found in deep water oil drilling platforms. It seems that it could decrease the energy of large waves by channeling some of their energy into the water density boundary layer below the rig, providing an extra margin of protection. I doubt that it would diminish waves at all frequencies, but it would be tuned for the most destructive energy band. If it is practical it would be very useful.
Ogg is dumber then a box of rocks. If dumping a bunch of random sized rocks on the ocean floor would protect an oil rig then they would already be doing it. These things are so expensive that if this worked it would be cheap insurance and standard to the industry. To the best of my knowledge dumping rocks is done in shallow water to protect coastlines and harbors, not in deep water. Even if Ogg knows how to spell "Gaussian harmonic" that doesn't mean he is refuting the content of the academic paper. The dumb description just says "ripples", which could actually be a structure like Ogg described. Ogg is throwing stones at a straw man. Ogg's critique is at the same level as a chimpanzee throwing it's shit at something, and has a similar intellectual content.
Why is Snark Required?
I don't see why people are assuming this would need a ton of power. How much power does a mirror consume, or a quarter-wave-plate? Changing the impedance of the water locally, or otherwise changin its dynamics, so that the wave energy takes a less destructive form as it passes the rig doesn't require power on the scale of the waves.
Socialism: a lie told by totalitarians and believed by fools.
There was a SciAm article about this mentioned on /. in the last decade or so, finding some merit in altering water composition locally to create locally calmer seas.
This approach alters local impedence through the shape of the ocean floor, not the composition of the water, but it's the same basic idea.
Socialism: a lie told by totalitarians and believed by fools.