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High-Tech Electro-Defroster

Zonk posted more than 8 years ago | from the you-can't-get-rid-of-ice-fast-enough dept.

109

DahBaker writes to mention a News.com story about an ingenious way to de-ice a surface. From the article: "Dartmouth College engineering professor Victor Petrenko, not to be confused with one of the Champions on Ice, has devised a way to use a burst of electricity to remove ice caked on walls or windows. For surfaces coated with a special film, the jolt gets rid of ice in less than a second, far less time than it takes to hack at it with an ice scraper. While drivers might find easy-cleaning windshields convenient, the technology--called thin-film pulse electrothermal de-icing, or PETD--could have significant economic impact if widely deployed. It could, for example, cut the costs of repairing power lines downed by ice storms and keep plane windshields frost-free, decreasing fuel consumption."

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109 comments

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Is it me.. (0)

Anonymous Coward | more than 8 years ago | (#15136169)

Or is slashdot not working?.. I don't see any comments for the last five hours.. that just doesn't happen ever, heh.

Re:Is it me.. (4, Funny)

MyLongNickName (822545) | more than 8 years ago | (#15136222)

Everyone was out on a hot date, or getting ready for the celebration of Christ's resurection. This is Slashdot after all.

Re:Is it me.. (2, Funny)

MadEE (784327) | more than 8 years ago | (#15136269)

It's Saturday! You expect people to browse here when they are not getting paid to do something else?

Re:Is it me.. (1)

(H)elix1 (231155) | more than 8 years ago | (#15136432)

Everyone was out on a hot date, or getting ready for the celebration of Christ's resurection. This is Slashdot after all.

Same thing we do every April 15th, Pinky... try to get our taxes done on time. Not sure if I'd call it a celebration. I actually was reading the tax code as 'the player' rather than 'the payer' as I slogged through schedule D. Sure sign of AD&D growing up...

Is it me..A Taxing Affair. (0)

Anonymous Coward | more than 8 years ago | (#15136462)

Hehe. It's nice to know I'm not the only one waiting till the last minute (April 17)*

*Although "/." did pick a bad time to do DB.

BTW Which Unreal engine is better? 2.0 or 2.5?

Re:Is it me.. (1)

dwater (72834) | more than 8 years ago | (#15136792)

Hey, we don't all live in countries with such stupidly annoying tax systems...(anymore)

Re:Is it me.. (1)

Medieval_Thinker (592748) | more than 8 years ago | (#15136588)

The celebration of the resurrection begins at sunset. I got back from the Vigil about an hour ago.

Ah yes... six readings and four psalms...

We can say "Alleluia" again.

Re:Is it me.. (0)

Anonymous Coward | more than 8 years ago | (#15136789)

Everyone was out on a hot date ... This is Slashdot after all.

I... no... can't reconcile... cognitive dissonance too high... aaaaaa *head explodes*

Re:Is it me.. (0, Flamebait)

pjbgravely (751384) | more than 8 years ago | (#15136237)

Testing, Testing,

Comments have been down since this morning but Zonk keeps posting stories.

Re:Is it me.. (0)

Anonymous Coward | more than 8 years ago | (#15136306)

LOL, I see Moderation is working again too :-p

Oh well, who needs Karma anyway

Re:Is it me.. (2, Funny)

Anonymous Coward | more than 8 years ago | (#15136245)

It says a lot about the editors when they post three (3) Ask Slashdot questions during a period when nobody can post comments...

Re:Is it me.. (2, Insightful)

topham (32406) | more than 8 years ago | (#15136329)

I tried posting, but received a message the database was down for maintenance. fair enough, but I thought it was kind of dumb to post Ask Slashdot questions then.

As for this article.. very cool. I need it on my car. bad.

Not just plane windshields (5, Insightful)

MadEE (784327) | more than 8 years ago | (#15136175)

Assuming the material is durable enough it would be great on the flying surfaces too preventing icing which adds considerable weight and changes the aerodynamics of the plane. This would probably be far lighter then current solutions for this.

Re:Not just plane windshields (4, Insightful)

Maxwell'sSilverLART (596756) | more than 8 years ago | (#15136354)

Assuming the material is durable enough it would be great on the flying surfaces too preventing icing which adds considerable weight and changes the aerodynamics of the plane. This would probably be far lighter then current solutions for this.

Actually, this was my first thought too, but after reading the article, I'm not sure how much use it would be in aviation. As you correctly point out, the big problem with ice in aircraft isn't the windshield, but airframe icing (wings and tail); ice (or even frost) changes the shape of the airfoil, destroying the lifting capabilities of the surfaces.

With a small panel, like a windshield, the power problem is manageable, but the leading edge of an airliner's wing is several hundred square feet (even a relatively small 737 has a wingspan of over a hundred feet for the later models, and you need to go at least a foot or two back on both top and bottom). Even assuming we only work on the leading edge, that's a hell of a lot of surface, and thus a lot of power. In reality, jet aircraft use hot wings, heated by bleed air from the turbines, and they heat the water on the leading edges enough that it stays liquid all the way to the trailing edge--these systems are more correctly called "anti-icing" than "de-icing."

Smaller aircraft do use de-icing systems, in the form of pneumatic boots. With such systems, ice is allowed to accumulate until it reaches sufficient thickness to be thoroughly broken by inflating the boots, causing it to crack and fall off (deploying the boots early can result in the ice simply forming around the shape of the inflated boots, rather than their deflated shape, rendering the boots ineffective). I'd be interested to see whether this system suffers from a similar problem, or if it is effective against even trace buildups.

The problem with it in light aircraft, though, is that such aircraft tend to have very low power budgets--there's not much surplus energy around. If there were, they'd use anti-icing systems, but intermittently shedding accumulated ice is very energy-efficient, especially when compared to energetic ice prevention (some aircraft carry alcohol anti-icing solution, which is excreted through "weeping wings" to forestall ice formation, but such systems are limited in the protection they can offer, both in severity and duration of icing conditions). Thermal anti-icing is cost-prohibitive, and electrical systems in light aircraft tend to be adequate, but with little overhead--while this system is more efficient than (presumably electrical) heating, it still may not be efficient enough. I'd also be interested to see what kind of electrical and magnetic noise this system might generate, though I'm sure that's been considered.

All in all, this sounds like a neat idea, but I'm not sure it's going to find its market in aviation.

Re:Not just plane windshields (2, Interesting)

Needles (132340) | more than 8 years ago | (#15136424)

When I was in school, during one of the ASME meetings we had a presentation of a device to remove the ice from the wings. The plan was to have a series of these plates on the leading edge of the plane. during normal flight they would be inlayed into the wing and be aerodynamic. If you were in an icing condition you would start a trickle charge a bank of compactors. Then once the charge was built up a series of panels would "pop" pushing the ice off the wing. Then the caps would recharge and a second series of panels would knock more ice off. and so on. Don't know what happened to the project. anything dealing with aviation takes a long time to develop. It has only been 8 years, which is not really that long for a industry with those types of safety standards.

Re:Not just plane windshields (2, Interesting)

Hal9000_sn3 (707590) | more than 8 years ago | (#15136459)

When I was at Cessna, working in the Experimental department, we tested just such a system. That was in 1985 or 1986. One major issue was that the interference with avionics was quite unacceptable, another was that the manufacturing cost was a lot more than the pneumatically inflated de-icing boots that were the status quo. It was quite fun to hold a penny near the leading edge and have it disappear, then hear it hit the wall on the other side of the hangar. Oh, yeah. That reminds me. Metal fatigue of the underlying structure. Simply not acceptable in aircraft.

Re:Not just plane windshields (1)

arivanov (12034) | more than 8 years ago | (#15137189)

IIRC Russians had a similar system ready for the launch of IL86 in the 80-es and abandoned it later for exactly the same reasons. Too much airframe stress.

Re:Not just plane windshields (2, Interesting)

MadEE (784327) | more than 8 years ago | (#15136434)

The problem with it in light aircraft, though, is that such aircraft tend to have very low power budgets--there's not much surplus energy around. If there were, they'd use anti-icing systems, but intermittently shedding accumulated ice is very energy-efficient, especially when compared to energetic ice prevention (some aircraft carry alcohol anti-icing solution, which is excreted through "weeping wings" to forestall ice formation, but such systems are limited in the protection they can offer, both in severity and duration of icing conditions). Thermal anti-icing is cost-prohibitive, and electrical systems in light aircraft tend to be adequate, but with little overhead--while this system is more efficient than (presumably electrical) heating, it still may not be efficient enough. I'd also be interested to see what kind of electrical and magnetic noise this system might generate, though I'm sure that's been considered.

The actual pulse needed to operate the stuff according to the article is in the manner of milliseconds all but the most heavily avionics laden aircraft should be able to handle the short pulse required to remove the ice from the surfaces.

Re:Not just plane windshields (3, Informative)

aibrahim (59031) | more than 8 years ago | (#15136514)

Maybe instead of "thinking" about the issue you should have checked out the company site where they have a video of ice being removed from an airfoil in a wind tunnel [iceengineering.com] .

That seemed like a fairly conclusive demonstration of the practicality of this process for that purpose.

Now where is that damn pretty floral bonnet of mine...

Re:Not just plane windshields (1)

OverlordQ (264228) | more than 8 years ago | (#15136751)

You entirely missed the point of the GP, he didn't say that it wouldn't work, he said it'd need alot of power to cover the vastly larger area compared to that little aerofoil.

Re:Not just plane windshields (1)

theonetruekeebler (60888) | more than 8 years ago | (#15139110)

To support your claim, I note that the electrical leads leading to the test airfoil are really frickin' gigantic.

But I also note that since the huge amounts of electricity only need to be delivered for a few seconds, that the power problem may be solved by

  1. dividing the airfoils into zones and de-icing them one at a time, and
  2. using capacitors or such to deliver the de-icing burst of electricity.

Re:Not just plane windshields (1)

noidentity (188756) | more than 8 years ago | (#15136906)

"Maybe instead of "thinking" about the issue you should have checked out the company site where they have a video of ice being removed from an airfoil in a wind tunnel. That seemed like a fairly conclusive demonstration of the practicality of this process for that purpose."

Well, I'm admittedly "thinking" here, but how does a demonstration in a wind tunnel, where there is practically unlimited power available, demonstrate that such a system wouldn't overburden the plane's limited available power, the issue the original poster spent most of his post discussing?

Re:Not just plane windshields (1)

DerekLyons (302214) | more than 8 years ago | (#15137012)

Maybe instead of "thinking" about the issue you should have checked out the company site where they have a video of ice being removed from an airfoil in a wind tunnel. That seemed like a fairly conclusive demonstration of the practicality of this process for that purpose.
Maybe *you* should think rather than take at face value a few seconds of video. The video is of a model (a very small one at that) removing a one time accumulation (rather that the ongoing accumulation more typical of real aircraft). In short, the video isn't conclusive of anything.

Re:Not just plane windshields (1)

theLOUDroom (556455) | more than 8 years ago | (#15137179)

Maybe instead of "thinking" about the issue you should have checked out the company site where they have a video of ice being removed from an airfoil in a wind tunnel. That seemed like a fairly conclusive demonstration of the practicality of this process for that purpose.

Looks like you completely missed his point.

OBVIOUSLY it *could* work, the question is does it make sense to do it this way?

If, for example, in that video they have to use as much power just to de-ice the wing as it would take to get the wing to typical flying velocity, then it simply isn't worthwhile.

Here's another example:
Theoretically, I *could* switch to an electric heater in my car so that I have instant heat when I get in. In reality, the amount of power required to do thisand the wa in which it is generated makes it uneconomical.

Don't listen to other repliers (1)

jgoemat (565882) | more than 8 years ago | (#15139102)

They all seem to say how hard it would be and how much power it would take. Do you know how much power is generated on an airplane? I don't, but I assume it is more than is generated by my car, and the car has do do this for the entire windshield, and possibly side windows and the rear-window. I'm pretty sure that the area to be defrosted on a plane's wings compared with the area of windows in a car is less than the ratio of power produced on a plane compared to that of a car. It looks like the de-icing only takes a second or two, so capacitors or batteries could be used to store the charge for the de-icing. If you are going to complain about how "hard" it would be for a plane, complain about a car first.

Re:Not just plane windshields (2, Informative)

aibrahim (59031) | more than 8 years ago | (#15139138)

I can see that being an ass generates a pile of interest. It unfortunately doesn't engender any actual reasoning, just more "thinking." You people are intellectually lazy.

Maybe I should try leading by example instead.

The key is that the GP says power, but he is really talking about energy budgets. This thing needs power over a very short time. Not a huge pile of energy.

How much energy... How about a calculation... oh dear is that sort of thing even possible on /. ? I'll try anyways. One caveat, whenever I trot out numbers: I *insist* you double check before believing them.

Lets pretend we are de-icing the entire surface area of a 747-400D, 541.2m^2. This is a huge overestimate of our work loads, because we really only have to defrost the leading edges and a foot or two back.

The C|Net article linked says he only needs to melt a micron or two for it to work, so we'll aim for three microns, or 3*10^-6 meters.

Ladies and gentlemen the total volume of water we are talking about over that vast area with the assumptions I have made is 1.6 mm^3. That is only about .146 grams of water.

That means we must expend .146 calories people. That's .611 joules.

You think a plane of any sort can spare lets say 611 joules, enough energy to de-ice the wings of a 747 a thousand times a flight ?

If you really think they don't have the energy budget, maybe we can just stick a D-Cell battery on board. Of course that's overkill because a D-Cell stores 10000 joules.

What about efficiency ? According to Petrenko's site at Dartmouth [dartmouth.edu] the system is wastes almost zero heat energy because of the short time over which it operates. Basically there is no time for it to go anywhere else.

You think we can somehow draw such a tiny amount of energy on even the flimsiest Cessna ? If not, I'm not getting into the damn thing.

In any case, it turns out Goodrich Aerospace has had good results flight testing the system on propeller driven aircraft, and is preparing to flight test it on jets. No details I got that from Petrenko's page at Dartmouth too.

Are you all starting to understand how cool this technology is ?

Re:Not just plane windshields (1)

arrrrg (902404) | more than 8 years ago | (#15140655)

I *insist* you double check before believing them.

Done, and belief duly suspended. You're only off by a factor of a million, not too bad ... you should have been more suspicious when you gave the "less than a gram" figure. Multiplying the above two numbers gives 1.6 x 10^-3 m^3 = 1.6 x 10^6 mm^3. You need to pay for converting to millimeters in all three dimensions, not just 1. Which makes your figure 611 MegaJoules ... IANAAE, so I don't know if that's gonna be lying around or not, but it seems that the GP may have had a point after all.

Re:Not just plane windshields (1)

aibrahim (59031) | more than 8 years ago | (#15141237)

Well, thanks and you were right up to a point. Of course the point is rather moot, as I said before they have already flight tested the system. (Read Petrenko's page for what little there is.)

Let's forget converting units and start again.

541.2m^2*0.000003=0.0016236m^3

The density of "solid water" at 0C is 915kg/m^3. Reference [simetric.co.uk]

That means we have 1.485kg of solid water to turn to ice. That's 1.485kcal or 6.217kJ.

As someone else pointed out I forgot heat of fusion [wikipedia.org] . That works out to ~497kJ. So, our total energy for a de-icing cycle is 503.3kJ.

If we actually feel the need to de-ice the plane 1000 times in a NYC to LA flight of about five hours... well that's once every 18 seconds. I picked it to be pie in the sky high. I don't think planes of any sort run that many de-icing cycles. In any case 503MJ isn't unreasonable for a 747 at all. A 747 uses 2.5TJ in a 5 hour flight. Yeah- terajoules. What's a few megajoules one way or another ?

We could just burn fuel from the aircraft to charge a capacitor, since aviation fuels range from 33-37MJ/liter. We could consider a system that combines that with batteries too. A truck battery holds ~5MJ, so you could use those for a few de-icing cycles. D-Cell's was wrong but still, even a Cessna can do the job of deicing a 747 wing.

Energy and power are not what will keep this off new planes. Cost of refits may keep it off old planes.

I picked a 747 on purpose. It has a huge wing area. Remember that a plane really only needs to deice the leading edges during flight. The wing area of the 747 dwarfs the area of the leading edges of the wing. The total leading edge area, going back about two feet for a 747-400 is about 160 m^2.

For comparison The total wing area (both wings planform top and bottom) for a Cessna 140 is ~32m^2. Thats less than an sixteenth of the area we were calculating.

32m^2*0.000003m*915kg/m^3=0.087kg of ice, that requires 367J+29.1kJ to overcome heat of fusion... 29.47 kJ.

That can easily be handled by a car battery, and in a pinch we can use a few D-Cells. Oh, and we are again deicing the whole wing, not just the leading edges.

The real point was and remains that this is entirely feasible. The GP was wrong regarding its central point, which was that the concept was entirely infeasible due to energy restrictions.

Re:Not just plane windshields (2, Informative)

ipfwadm (12995) | more than 8 years ago | (#15140935)

Someone else already pointed out your obvious mistake in converting cubic meters to cubic millimeters, but that's not the only error...

the total volume of water we are talking about over that vast area with the assumptions I have made is 1.6 mm^3. That is only about .146 grams of water.

Isn't one of the supposed beauties of the metric system that you can deal with powers of 10? So how can it possibly be the case that 1.6 cubic millimeters is equivalent to .146 grams? That would be a factor of 10.9589. Of course, even if we were to use a factor of 10 we'd still be wrong since you again screwed up the conversion due to not working in three dimensions: there are 1000 cubic millimeters in a cubic centimeter, not 10. So if the starting number were really 1.6mm^3 (which it's not as the other poster pointed out), that would equate to 0.0016 grams of water, not 0.16, and certainly not 0.146.

So, combining the original screw-up (which made your number low by a factor of a million) with this one (which made you high by a factor of a hundred), as well as your whacked out mm^3 -> gram conversion (which made you low by 10%), the final answer should be... about 6.8 kJ. Or 6.8 MJ if you want to do it a thousand times in a flight.

But wait, there's more! You're assuming that the temperature of the ice needs only be raised by 1 degree C. The article says it needs to be raised TO 1 or 2 degrees C, but who knows what the starting temperature of an iced-up wing is. But let's say we need to raise it 5 degrees. Now we're up to 34 kJ.

But wait, there's STILL more -- and this one's a biggie! You're (conveniently) ignoring heat of fusion. Remember that from chemistry class? So tack on another 334 joules per gram of water. At 1600 grams, that's another 534kJ every time you fire off this thing, for a grand total of 567kJ per use, or so many megajoules if it's used 1000 times in a flight. Not gonna de-ice a 747 with a D cell anymore, are we?

And just as an aside, 541 meters^2 isn't as big an overestimation as it may seem at first glance, because that is not the "total surface area" of the wings, it is the wing area. You'd need to multiply 541 by 2 to get the total wing surface area, as wings have two sides - you know, a top and a bottom. You may even need to multiply it by a little more than 2 since I'm assuming wing area is just the area of the wing's planform, and not actual surface area which would be higher due to the airfoil shape, but I'm not an aeronautical engineer so I don't know.

Don't post innacurate information

How about your hideously wrong math, does that count as inaccurate information? And what about your hideously wrong spelling of inaccurate?

Re:Not just plane windshields (1)

aibrahim (59031) | more than 8 years ago | (#15141239)

I answered most of your issues in another post.

The highlights-

Powers of 10 ? Sure, but we are dealing with real materials. Real water has a density [simetric.co.uk] of 915kg/m^3 in solid form (aka ice) at 0C.

As I said in the original post, we don't have to deice the entire wing, just the leading edges and a foot or two back. For a 747 the total is ~160m^2. So yeah- it is a huge overestimate in our workload.

I did forget heat of fusion, so call it a car battery.

Its reasonable to consider raising the temp only 1 degree for two reasons. Heat of fusion is >> heat to change temp. More seriously, if there were reason to believe they had to change the temp that much they'd deice more often, that's why I came up with the ludicrous notion of deicing 1000 times a flight. That once every 18s on a 5 hour flight.

I used surface areas according to where I looked up the info, but even if I used planforms it would be fine. This is /. not Boeing. Plane wings are pretty thin. Once you do the math right there are fudge factors aplenty elsewhere. Its close enough.

Despite my 'hideously' wrong math my point remains cogent- this is feasible.

Lastly 'innacurate' is supposed to be inaccurate. Get it ? Humor, in this case self effacing. I thought the silly concept of a floral bonnet (Firefly reference to boot) just might have clued you in. I use OS X and Safari. Safari underlines incorrectly spelled words- its pretty hard to make a mistake like that.

Now if only I had mathcheck in the browser.

Re:Not just plane windshields (1)

drkich (305460) | more than 8 years ago | (#15136526)

As you say, the power consumptions might not be the greatest.

However think of this scenario. First a disclaimer, I am not in the aviation industry.

What if this technique of removing ice from wings and other surfaces were used only while they were plugged in at the terminal. No need for chemicals or the engines to be running. The cost of electricity is far cheaper than a gallon of aviation fuel.

Re:Not just plane windshields (1)

ccmay (116316) | more than 8 years ago | (#15136849)

What if this technique of removing ice from wings and other surfaces were used only while they were plugged in at the terminal.

That's not practical. The plane really needs the de-icing while in flight, because one of the major causes of aviation accidents is ice accumulation changing the shape and efficiency of the airfoil. Eventually the plane can no longer maintain altitude even at full power.

And if it's not usable in flight, what does the airline get for the expense and added weight that the plane must carry for a system it can only use on the ground? We already have good ground-based de-icing systems.

-ccm

Re:Not just plane windshields (2, Insightful)

drkich (305460) | more than 8 years ago | (#15136881)

I guess one of the points is, with the de-icing fluid carrys cost with it. One for the actual cost of the liquid, two the environmental clean up and three the man hours to do the work. And if I recall correctly, do they not actually sometimes do it multiple times before take off?

So the question is, over the life of the plane, and the number of times it will be deiced, what is the cost benefit ratio. Do we save money even with the extra weight? Or is it still cheaper with the old method? That is something for the accountants to figure out. I am sure someone, somewhere will at least do the study.

Re:Not just plane windshields (2, Insightful)

Silentnite (815125) | more than 8 years ago | (#15137416)

Since no one else here is going to pipe in with airline experiance I may as well.

When you de-ice/anti-ice an aircraft you spray it with a chemical. The De-ice is by all other virtue and for the sake of this argument just hot water. The Anti-ice is an expensive(and I mean EXPENSIVE) compound that resembles the slime left in the wake of ghostbuster's three with slimer(was that three? or two?). In order to provide an effective coating and bumping up the hold-over times(the time to get from the gate and into the air) you need a good thick coat. Mind you it slides off after takeoff once they get up to speed, but the reason its accounted for in airplane weight is the take off. Due to the excess weight of the anti-ice fluid, planes need longer to take off, and usually can carry less.

Ah, if only we could load people and bags in the air like the airforce does with fuel. Damn.

Re:Not just plane windshields (1)

RobertLTux (260313) | more than 8 years ago | (#15139413)

sorry we can only have people and baggage disenbark during flight (hopefully one of the bags is a chute of some type

Re:Not just plane windshields (1)

Silentnite (815125) | more than 8 years ago | (#15140779)

Hey there's an idea for an extreme sport. Diving BACK into a plane. HA!

flying ice (1)

openfrog (897716) | more than 8 years ago | (#15136533)

If you de-ice the wings of an aircraft flying at, say, 900 km/h, you are sending said ice toward the tail of the plane at same speed, repeating a recipe that caused, err, a major malfunction not so long ago at the occasion of a shuttle launch, aren't you? And that was not even ice, but just foam. Granted, the place will not have to suffer the penalty of a reintry into the atmosphere, but it is now understood that light debris flying fast can cause serious damage.

Re:flying ice not foam (1)

NinerSevenTango (968036) | more than 8 years ago | (#15136811)

The foam was several inches think, waterlogged and frozen solid. The vehicle was traveling at great speed. The heavy, solid, ice-laden foam had a relatively long distance to decelerate before the leading edge of the wing hit it. And the damage was to the heat resistant tile; it was the failure of the tile that brought the aircraft to its end.

In atmosphere - bound aircraft, the systems that shed ice are designed to shed it in small pieces at intervals that preclude it from building up too thick. Also, the speeds and distances are a lot smaller.

In short, they do think of these things.

What's fun is to be sitting in the seat that is in line with the propeller on a turboprop plane when the prop sheds its ice.

I never sit in the seat that's in line with the prop on those planes.

--97T--

Re:flying ice not foam (0)

Anonymous Coward | more than 8 years ago | (#15137451)

I never sit in the seat that's in line with the prop on those planes.

I don't either -- but not because of ice. If I'm anywhere near the "prop row", during the entire flight my mind keeps replaying a picture I saw years ago showing what happened when a prop blade got loose and entered the cabin. My mind doesn't seem to understand that the event happened on the ground (IIRC, because a vehicle and plane tried to occupy the same space at the same time while the plane's engines were spun up).

Re:flying ice not foam (1)

shmlco (594907) | more than 8 years ago | (#15137624)

"And the damage was to the heat resistant tile; it was the failure of the tile that brought the aircraft to its end."

I thought that, according to the findings of the review board, the damage was to one of the curved carbon-carbon panels that covered the leading edge of the wing, and not to the heat resistant tiles the cover the underside? Carbon-carbon composite is not the same thing as heat resistant ceramic tile.

Re:Not just plane windshields (4, Informative)

darthwader (130012) | more than 8 years ago | (#15136627)

(deploying the boots early can result in the ice simply forming around the shape of the inflated boots, rather than their deflated shape, rendering the boots ineffective.)

I really hope that no pilots are getting their flying advice from slashdot (just like no lawyers are getting legal advice here), but just in case: the latest research indicates that ice bridging is a myth, and you should use the boots as soon as you detect any icing, rather than waiting for build-up.

http://www.aopa.org/pilot/features/inflight9910.ht ml [aopa.org] , http://www.elliottaviation.com/wavelink/1999q1/wav art21.asp [elliottaviation.com] and http://www.faa.gov/library/manuals/examiners_inspe ctors/8400/fsat/media/fsat9818.doc [faa.gov] are good references.

http://www.pilotfriend.com/safe/safety/icing_condi tions.htm [pilotfriend.com] is a great article about all sorts of aircraft de-icing and anti-icing methods.

Re:Not just plane windshields (0)

Anonymous Coward | more than 8 years ago | (#15140661)

It's a slow change in the aviation community. Just because it looks high-tech from the ground don't mean we ain't flyin' in the 1950s! (Of course, I'm a General Aviation guy -- airlines and militaries may be in the 1970s, with some avionics from the mid 1990s.)

Re:Not just plane windshields (1)

jbf (30261) | more than 8 years ago | (#15136996)

The major problem with frost is not the change the shape of the airfoil; it disturbs the smooth airflow over the wing surface, causing turbulent separation, dramatically lowering lift.

http://www.ultralighthomepage.com/STALL/stall.html [ultralighthomepage.com]
http://www.av8n.com/how/htm/airfoils.html [av8n.com]

Re:Not just plane windshields (0)

Anonymous Coward | more than 8 years ago | (#15140533)

And why does ice dusturb the airflow over the wing surface? Because it changes the shape of the wing. Granted, it's on a micro-scale, so it may be more descriptive to say the ice changes the texture... or smoothness.

Re:Not just plane windshields (0)

Anonymous Coward | more than 8 years ago | (#15138070)

but airframe icing (wings and tail); ice (or even frost) changes the shape of the airfoil, destroying the lifting capabilities of the sur1faces.

That's actually a common misconception. Frost does not change the shape of the airfoil, rather, it only disturbs the air flow over the airfoil thereby destroying lift. Ice, on the other hand, can do both, spoil life and change the shape of the airfoil.

Re:Not just plane windshields (1)

pipingguy (566974) | more than 8 years ago | (#15136492)


This would probably be far lighter THAN current solutions for this.

You didn't think we self-important (for lack of better things to do) word Nazi pricks would go away just because of a six hour Slashdot meltdown, did you?

How about appliances? (1)

Walt Dismal (534799) | more than 8 years ago | (#15136523)

No more defrosting refrigerators! It would beat putting naked orphans with ice picks into my freezer, too. Er, not that I do that. The human remains in my garbage can were from some other pervert, officer...Not me.

This can't be first.. (0, Flamebait)

Kreigaffe (765218) | more than 8 years ago | (#15136186)

10 bucks says it's not. now to go RTFA because this sounds incredibly appealing, as I am lazy and dislike scraping my windshield. If only they could make this work with all the snow around my car, too..

Re:This can't be first.. (0)

Anonymous Coward | more than 8 years ago | (#15136313)

how is that flame bait? crappy post, yes. flame bait, no.

Re:This can't be first.. (1)

Kreigaffe (765218) | more than 8 years ago | (#15136346)

Crappy post indeed! I was sadly excited by the possibility, after all these years, of having a first post. FAILURE!

However, several of these top posts were all modded flamebait -- mine should be modded Dumb, but the other two were actually above-average for slashdot!

Well, whoever it is, let's just all hope that the good other mods burn their points to help us unfortunates who have been unfairly labeled as Flamebait -- and whoever that is, gets nuked from orbit and never mods again.

It's the only way to be sure.

cheap solar power (1, Interesting)

dokebi (624663) | more than 8 years ago | (#15136252)

from the article:
"We built a solar cell made of ice," he recalled. "While it is not as efficient as a silicon solar cell, it costs a penny a square mile."

Solar panel that uses ice! This could be very cool for people in colder climates.

Re:cheap solar power (1)

kfg (145172) | more than 8 years ago | (#15136449)

So lessee, if I've got this right I'll be able to heat my house in the winter by turning my patio into a skating rink with super bonded ice and when it gets too warm to maintain it simply reverse the polarity and zap it clean.

I think I might be willing to sign up for that.

I wonder how small you could make ice semiconductors.

"Yeah, the server's down. The CPU, ummmmmmmmm, 'melted down' when it overheated to 1C."

Maybe that's a better idea for Greenland than Brazil.

KFG

Re:cheap solar power (1)

altagir (259584) | more than 8 years ago | (#15136454)

Indeed but technology could also simply be used to simply remove ice on solar panels. I live in Quebec which has a gret deal of sun exposure but use of solar panel are of no use since they would regurlarly get covered with ice or snow. Since most our roofs are flat, a great deal of surface could be used to have auxiliary power during our chilling winters.

Mars? (1)

WindBourne (631190) | more than 8 years ago | (#15136559)

Depending on the efficiency, this might work on Mars. Particurly, if it is easy to construct.

Save the Ice! (1)

NotQuiteReal (608241) | more than 8 years ago | (#15136821)

You insensitive clod - think about the coming global warming.

You can't use the ice for making electricity - I need it for my drink!

Re:cheap solar power (1)

thatkeith (916250) | more than 8 years ago | (#15137418)

Marvellous. Just don't use it for heating, eh?

"Honey, what happened to the solar panel..?"

Re:cheap solar power (1)

solitas (916005) | more than 8 years ago | (#15138440)

Solar panel that uses ice! This could be very cool for people in colder climates.

Yeah - and ray nagin will just bitch all over the place that nobody's takin' the tech down south to help him rebuild his New Orleans-ian utopia.

Freezing rain (0)

Anonymous Coward | more than 8 years ago | (#15136277)

I think this invention would be something for Canada and the northern states in the U.S. to consider. We've seen some really nasty freezing rain [wikipedia.org] over the years. Covering core infrastructure with this defroster could save us quite a bundle of cash, even if the initial cost is expensive.

Sure, the windshields are more important. (2, Insightful)

TheDreadSlashdotterD (966361) | more than 8 years ago | (#15136285)

It could be more useful on the wings. Keeping a plane in the air might be important too.

Re:Sure, the windshields are more important. (1)

whitehatlurker (867714) | more than 8 years ago | (#15136364)

This site [dartmouth.edu] shows a range of the applications available. I'm sure that easteners would be interested in the de-icing of transmission towers [wikipedia.org] . (Too bad this won't remove trees [wikipedia.org] .)

Re:Sure, the windshields are more important. (1)

squeemey (925509) | more than 8 years ago | (#15136508)

Thanks for the link.

I am wondering what problems will have to be overcome, mostly the durability problem. How long will the product last?

It will boil down to an economics problem in the end. Continued improvements in materials will determine applications.

Re:Sure, the windshields are more important. (1)

ThatsNotFunny (775189) | more than 8 years ago | (#15136397)

Yeah, let's run a jolt of electricity... WHERE THE FRICKIN' JET FUEL IS!

Re:Sure, the windshields are more important. (0)

Anonymous Coward | more than 8 years ago | (#15136429)

Um.. the fuel system is already electronic and so are the controls.. and most jets already have some kind of defrost system running on the wings.

Scratch resistant? (0, Redundant)

bidule (173941) | more than 8 years ago | (#15136392)


This being /. and me being me, I didn't RTFA. If this is scratch-resistant and can be applied to non-glass surface, it could eliminate the anti-freeze applied to aircrafts before take-off. This would greatly reduce pollution there.

Misread (0)

Anonymous Coward | more than 8 years ago | (#15136421)

Did anyone else read this as "High-Tech Electro-Disaster"?

The video is not impressing... (1)

DasOrobas (963562) | more than 8 years ago | (#15136443)

Has anyone seen the video demonstrating the technology? Yeah, they can remove a very thick layer of ice or snow, but I'm pretty sure it would be much harder with a very thin layer, on a surface that isn't oriented at 90 degrees.

Crank Invention (1)

Doc Ruby (173196) | more than 8 years ago | (#15136593)

I'd love to see the car version chargable by cranking the charger inside. Same energy efficiency, same exercise program, but much more comfortable.

Re:Crank Invention (0)

Anonymous Coward | more than 8 years ago | (#15136952)

why bother? that's what the battery is for. you driving around in a model T?

Re:Crank Invention (1)

Doc Ruby (173196) | more than 8 years ago | (#15137747)

The energy doesn't "come from" the battery - it's just stored there. It comes from the gasoline, so this deicer will consume even more gas. And deicing is part of many Northerners' Winter exercise program.

Get a clue before posting, Anonymous pampered Coward.

Does this quote from TFA sound like BS? (1)

antispam_ben (591349) | more than 8 years ago | (#15136668)

The technology essentially takes advantages of the inherent properties of ice. Ice, it turns out, is a semiconductor, meaning that it conducts an electrical charge under certain circumstances.

This appears okay so far, but as in any popular writing about a technical or scientific subject, use of such words as "under certain circumstances" is excessively vague. One can only hope that a later sentence clears this up. But that doesn't happen here.

Unlike silicon, which conducts negatively charged electrons, ice conducts protons, the core of hydrogen atoms that are part of the water molecules.

So the article is that the proton is the charge carrier in ice conduction?

In a "P type" semiconductor doped for positive carrier conduction, it's the 'holes' that move and carry the charge, though their movement is correlated with electrons moving the opposite direction. I know of positively charged particles moving in a plasma (such as an electrical spark), but not in a solid.

Does the author (or the person who tried to explain it to him) mean that ice uses holes as the charge carrier just like P-type semiconductor, and he just messed it up/reinterpreted it as protons?

What's so frustrating about these watered-down "popular science" type articles is it's impossible to know if I'm reading something that is truly new to me, or (as I always suspect and too often find) it turns out I already know more than the writer ever will.

Can someone post a REAL article on this topic?

Short correction to text... (1)

antispam_ben (591349) | more than 8 years ago | (#15136701)

So the article is that the proton is the charge carrier in ice conduction?

should read:

So the article is saying that the proton is the charge carrier in ice conduction?

Re:Yes It Sounds Like BS (1)

NinerSevenTango (968036) | more than 8 years ago | (#15136930)

The BS detector is ringing -- fact free news article, company website with no information, and no products to buy. Sounds like a stock swindle, to be blatantly impolite about it. A few questions that come to mind, that aren't addressed anywhere; 1) As mentioned, proton conduction, instead of electrons? Huh? Is there some electrolysis going on? If so, why is it not mentioned? 2) This talk of ice being a semiconductor -- OK perhaps, but then if you put a film on a surface, then cover it with ice, then 'pulse' it, how exactly to you get current flow through the ice which is supposed to conduct current through its protons? In other words, you need something to complete a circuit. I could postulate that it is electrostatics, but shouldn't the claimant explain this? (Ice doesn't fly off transmitting antennae.) 3) It is mentioned that you need to bring the surface to very close to freezing temperature for it to work. This implies heating of the surface with these pulses, not heating of the ice. So obviously the energy density required will depend on a lot of external factors. This rather sounds like a method for rapidly heating the surface, rather than something to do with ice being a semiconductor. 4) A solar cell that costs pennies per square mile? And we are not getting free electricity from it because ? ...... 5) Any conductor that is pulsed with high enough current jumps because of the magnetic field. If it is coated with ice at a temperature near freezing, it seems likely that it could shed the ice. How much is really new here? The BS detector is on high alert. Real information, products with price tags will be required to silence it. --97T--

Re:Does this quote from TFA sound like BS? (2, Informative)

Manchot (847225) | more than 8 years ago | (#15136933)

Well, this New Scientist article [newscientist.com] from 2002 is also about Victor Petrenko, and goes into a little more depth.
 
Apparently, it is is the protons which are the majority charge carrier. If you remember your high school chemistry, there exists a small amount of hydrogen and hydroxl ions even in water with a pH of 7. Presumably, ice, which is a crystalline version of water, also has a small concentration of hydrogen and hydroxyl ions. According to the article, the free hydrogen ions (a.k.a. protons) travel between the crystalline structure of the ice, carrying current. I would guess that the hydroxyl ions don't do the same thing simply because they are much larger than hydrogen ions, and are effectively immobile in the lattice.

Re:Does this quote from TFA sound like BS? (0)

Anonymous Coward | more than 8 years ago | (#15137254)

No. It has *nothing* to do with free hydroxide or protons. It has to do with imperfections in the crystal lattice in which water molecules exist that do not have all of their hydrogen bonds satisfied. This allows protons to jump from one oxygen to another in one direction.

Proton conduction can also occur by "moving" bonds from bond protons to hydrogen bound protons -- but this only gets you so far and in a perfect water crystal I suspect you could create a capacitor.

Re:Does this quote from TFA sound like BS? (0)

Anonymous Coward | more than 8 years ago | (#15138084)

what about proton exchange mambranes in fuel cells?

Re:Does this quote from TFA sound like BS? (1)

barawn (25691) | more than 8 years ago | (#15139981)

Does the author (or the person who tried to explain it to him) mean that ice uses holes as the charge carrier just like P-type semiconductor, and he just messed it up/reinterpreted it as protons?

The holes are protons (or at least, they could be. I need to find a decent article on the process to see: let's just assume it's really the hydrogens are proving the effect, and not the oxygens, okay?). Holes [wikipedia.org] are just unfilled states in a valence band.

If you imagine pure hydrogen, for instance, the valence bands are - well - the electrons. A hole in pure hydrogen, then, is going to be located at a proton.

Now, that's still not entirely right, though, because while the hole would be located at the proton, it wouldn't be the proton, because if you talk about the hole moving, it would really be an electron moving - that is, an electron from an adjacent proton would hop over, and the 'hole' would move.

So the author is both right, and wrong.

But to be fair: the slipup that he's making is very often made. It's akin to saying 'electrons move at a third the speed of light in a copper conductor' - which is wrong. But also to be more fair - if you posted a video of the process, it really would look like a proton was being conducted along. It's not like you can tell the difference between the proton that's got an electron around it and the proton that doesn't.

High tech, how? (2, Insightful)

evilviper (135110) | more than 8 years ago | (#15136784)

I must be missing something... Maybe the article is just light on details, but I can't see how this is any more advanced than the rear window defroster standard in every car made in the past couple decades.

Electricity turns to heat, and melts the ice. Yippie. In this instance it sounds like electricity is being applied directly to the ice, possibly making this slightly quicker and more effecient, but I don't see anything revolutionary here. I also can't see how this is any less obtrusive...

Re:High tech, how? (1)

springbox (853816) | more than 8 years ago | (#15137074)

I doubt you read the article, but I'm pretty sure that your car's defrosters don't make any icy buildups slide off in large chunks instantly. Watch the video for flying ice action.

Re:High tech, how? (1)

solitas (916005) | more than 8 years ago | (#15138420)

...I'm pretty sure that your car's defrosters don't make any icy buildups slide off in large chunks instantly

Yeah, and the 'icy buildups' on _my_ windshields don't appear to be pounds-heavy solid square blocks that look like they're only adhering to the glass because someone laid a piece of warm glass on an ice block in a freezer.

A conformal, self-supporting coating of ice isn't going to drop off as prettily as his ice blocks do. Next winter: go sit in an iced-over car and start up the defroster. It doesn't take a lot of time to get the ice to release (even with warm air on the other side of the glass compared to a coating on the ice-side). You also have to disturb enough supporting ice to that the layer will slide off (not to mention having to break the 'suction' of surface against surface.

Electrically conductive coatings on glass is nothing new and it only takes the smallest time for the heated coating to melt a thin interlayer to release the ice. AND, that coating HAS to have a protective overcoat because if the oxide coating gets a scratch then it interrupts the current and you get higher current densities around the ends of the scratch and accelerated breakdown and arcing.

I used to work for a gov't contractor that supplied doors, windows, wipers, heated windows, etc. to the USN & USCG. Heated windows (non-icing for bridge & flight ops) were the biggest part of our business.

Re:High tech, how? (1)

evilviper (135110) | more than 8 years ago | (#15139640)

I doubt you read the article,

You're only completely wrong... I guess that's close enough.

but I'm pretty sure that your car's defrosters don't make any icy buildups slide off in large chunks instantly.

Sure they do. Give them a minute or so to warm up, and start driving.

On an airplane windsheild, the air is going several hundred MPH, and would work infinitely better than on a car.

Watch the video for flying ice action.

I don't have Flash installed, and I have no intention of ever installing it again.

I'm with you on this (1)

goldcd (587052) | more than 8 years ago | (#15137608)

My exceptionally boring (yet I love it to bits) Ford Focus (3 years old) has loads of tiny heating elements built into the front windscreen. I press a button on the dashboard an in about 15 seconds it's melted whatever happened to be stuck to the windscreen. Well actually it's more like what described here, it melts the layer between the ice/snow and the glass, so as you drive or use the wipers it all just comes off in chunks.
The only advantage I can see with this method is that it's a bit faster and I assume cheaper to make (I got the windscreen bundled in my package, the cost of replacing it is astronomical seemingly).

Re:I'm with you on this (0)

Anonymous Coward | more than 8 years ago | (#15137685)

The Ford Escort I bought 15 years ago already had this. And while at that time it was newish in cars of that class, larger Ford models had it even before that.
I really liked it, becuase it not only removes ice but it also very quickly clears the window of condensation. Much better than using the blower, which is not very effective when the engine is still cold.

Strange that this feature has not yet found its way into other car brands.

Re:High tech, how? (1)

necro81 (917438) | more than 8 years ago | (#15139435)

This device works on a different principle than your rear defroster. In your car, you have actual heating elements that have electricity passed through them, which in turn give up their heat to the ice. The problem is, however, that the applied heat quickly conducts away from the ice-windshield interface and into the bulk. Heating the bulk ice does no good at all. We all know how high the heat capacity of ice and water is - it takes a ridiculous amount of heat energy to melt ice into water. In addition, a rear defroster's heat is applied only along the heating elements, and it takes a long while to melt the ice inbetween the elements.

What this device does is induce HF currents directly in the ice-windshield interface - no heating element needed. It heats up the entire interface area almost instantaneously to liquid, fast enough that very little of the heat has a chance to conduct away into the bulk. The result is the near-instantaneous formation of a water layer between the bulk ice and the windshield, allowing the ice to slide ride off.

The device takes a relatively high amount of power to work. But, because it works so quickly, and in a pulsed fashion, it consumes very little energy - only as much as it takes to melt the ice-windshield interface, rather than wasting energy heating the bulk ice. Hence, it is considerably more efficient, not to mention a lot faster.

What about frost free freezer? (0)

Anonymous Coward | more than 8 years ago | (#15136827)

One of the biggest problems with frost free freezers are that they have to warm up above freezing, on a regular schedule, so that they don't frost up.

The problem is that outside/edges of frozen items also thaw a bit creating all sorts of problems. (ice crystals on your popcicles for example!)

That's why a deepfreeze(non-frost free) freezers are recommended
for longer term storage.

A quick thaw of the surfaces where ice builds up
would keep the feezer ice free and the food frozen.

Re:What about frost free freezer? (1)

ChrisMaple (607946) | more than 8 years ago | (#15139689)

I think your idea would almost work. Ice would be shed from the top and side surfaces, and fall to the bottom, ending up as a layer of crushed ice. This would have to be shoveled out occasionally, hopefully before it coalesces into a big chunk.

FriSt psot (-1, Troll)

Anonymous Coward | more than 8 years ago | (#15136893)

Champions of the Ice (3, Funny)

roman_mir (125474) | more than 8 years ago | (#15137091)

Victor Petrenko, not to be confused with one of the Champions on Ice - If you put those two into the same room, hilarity and confusion are bound to ensue, since they seem to be the Ice Champion and the Anti Ice Champion, the Ying and the Yang. We must keep them as far away from each other as possible, or there could be an anti-matter equivalent explosion.

Re:Champions of the Ice (1)

Aladrin (926209) | more than 8 years ago | (#15137622)

That comment would have been a lot cooler if you'd spelled 'Yin' right.

Road Deicing (1)

lordsid (629982) | more than 8 years ago | (#15137239)

Why not use it on roads for deicing? It gets rediculous in some parts of the country.

Re:Road Deicing (0)

Anonymous Coward | more than 8 years ago | (#15138626)

Uh, my first guess would be gravity. The ice would have nowhere to go and just freeze to the road again. OTOH, the article does say that civil engineers in Sweden tested PETD on the Uddevalla bridge and decided to use it. Maybe it just turns the ice into slush or something. So my second guess would be the energy requirements.

Re:Road Deicing (1)

HermanAB (661181) | more than 8 years ago | (#15139369)

The used the technique to remove ice from the bridge structure, not the road surface.

1c for a square mile of solar panel (0)

Anonymous Coward | more than 8 years ago | (#15137277)

The last sentence interest me - 1c for a square mile of solar panel. Just think - all the electricity need generate in north pole

Shuttle Foam (1)

LiquidCoooled (634315) | more than 8 years ago | (#15137380)

Could they use something like this on the outer tanks of the shuttle instead of foam?

Breaking and removing this ice before it becomes a huge iceball could be double plus good.

Forget the stuff about semiconductors (2, Insightful)

Flying pig (925874) | more than 8 years ago | (#15137572)

For windshields, this just seems to be all over defrosting from the inside by a fast pulse, a fast version of what Ford have been doing for years. You still have to remove the ice mechanically before it refreezes, otherwise the sheet will just stay in place and, as the article says, bond even more tightly than before (I've noticed this with Ford windshields - if you don't complete the melt cycle for some reason, you can get very firmly bonded ice.) Plus, what's the world indium supply like? And what is the chance of cracking the windshiled due to thermal shock? Heating the outside to 2 degrees C while the inside is at -10 doesn't sound terribly smart.

So I suspect that to commercialise this a lot of research will be needed. Changes to windshield composition and design. Changes to wiper design. Uprated batteries. It might actually be cheaper to fit one of those nice Kenlowe or Eberspacher heaters with mobile phone control so you can simply start the car heating ten minutes before you leave the house or the office. After all, no matter how well the pulse technology works, at the end of it you are sitting in a freezing cold car, even if you can now see through the windshield.

Re:Forget the stuff about semiconductors (1)

theonetruekeebler (60888) | more than 8 years ago | (#15139158)

You still have to remove the ice mechanically before it refreezes,

I see you've found the tragic flaw in their idea. If only there were some device that could "wipe" the windshield as you deiced it.

not new pricey answer to a nonexistent problem. (1)

Ancient_Hacker (751168) | more than 8 years ago | (#15137714)

A few drawbacks to this idea:
  • Electrically heated windshields, propellers, etc... have been around for 70+ years.
  • Jet planes spend 95% of their flying time way above or below the icing levels.
  • Jet turbines have a virtually free and unlimited amount of hot air availbale for deicing.
  • It's not affordable to load down a plane with 100's of pounds of extra generators, batteries, and/or capacitors that are only needed in very rare and usally avoidable circumstances.
  • The planes that would need this the most, little prop planes that can't climb above icing, are also the ones that can least afford the weight penalty of this deicing system. Adding even 150 pounds to a small plane can make it a non-viable flying machine.
  • Even if you outfitted a small plane with wing de-icers, it would also need pro de-icers, which are either alcohol squirters or electrical heating elements, either of which are quite expensive to install and maintain.

Re:not new pricey answer to a nonexistent problem. (3, Interesting)

necro81 (917438) | more than 8 years ago | (#15139528)

Preface: I was a grad student at the Thayer School of Engineering, where Petrenko does this research. During a power electronics class, we learned about the workings of some of this technology, and some classmates of mine designed some of the HF electronics that are behind this.

Electrically heated windshields, propellers, etc... have been around for 70+ years. Yes, but those devices have heating elements that conduct heat into the bulk ice. You don't want to spend all the energy needed to melt all of the ice, or even a sizeable portion of it, but rather melt just the ice that's adhered to the windshield or airfoil. This technology does that. It creates HF eddy currents in the ice at the ice-windshield interface, liquifying that thin layer almost instantly. The liquification happens quickly enough that very little heat is conducted away into the bulk, which means that you aren't wasting or losing much energy. What's more, the heat is applied directly to the ice - no heater elements needed. Instead of pumping XX watts of power into heater elements and waiting for enough ice to melt to easily be removed, you pump (let's say) 10 times the power for 1/1000 the time into just the ice that matters, then let gravity, airflow, and wiper blades take care of the rest. It is a far more efficient way to remove ice.

Jet planes spend 95% of their flying time way above or below the icing levels. Unfortunately, the place where icing is most likely is also the place where it is most dangerous: during takeoff and landing. Just because it is not a continuous threat during the flight doesn't mean that it isn't still extremely dangerous.

Jet turbines have a virtually free and unlimited amount of hot air availbale for deicing. The hot gasses need to be hot if they are to produce thrust. Were the gasses diverted through some complicated heat exchanger to melt ice from the airfoils of aircraft, the exit gasses wouldn't produce nearly as much thrust. Once again, this technology works only on the ice that is adhered to the surface, and so works very efficiently. Using hot gasses, like heater elements, inevitably has most of its heat conducted into the bulk, where it does little good.

It's not affordable to load down a plane with 100's of pounds of extra generators, batteries, and/or capacitors that are only needed in very rare and usally avoidable circumstances. This is not additional equipment for an airplane, it is meant to replace the de-icing equipment that some already have. Consider the cost of applying thousands of gallons of chemical de-icing to aircraft wings on the ground, or the electrical equipment needed to generate the huge amount of electrical power that goes into heating elements. If anything, this technology would have less equipment associated with it than other methods, because it uses far less energy. The amount of energy that it takes to use this equipment, even over the entire leading edge of an aircraft's wing, it relatively small compared to the power needed to run everything else, or the tremendous power output of the engines. It makes use of high-frequency power electronics, which are much more compact and efficient than traditional power electronics. True, it isn't need all the time, but there is tons (literally, tons) of equipment in an airplane that is only used occassionally. They all serve a specific purpose. I will admit that it will be expensive technology at the beginning, especially for retrofits, but most new technology is. Airbags were initially only seen in high-end luxury cars, but eventually trickled down to lower models.

The planes that would need this the most, little prop planes that can't climb above icing, are also the ones that can least afford the weight penalty of this deicing system. Adding even 150 pounds to a small plane can make it a non-viable flying machine. Once again, this is not additional equipment, it is meant to replace existing de-icing equipment on a plane. It would not, NOT, weight 150 lbs. for a small prop plane. Refer to the preface - I am familiar with this technology, and have seen it in person. It is not that large.

Even if you outfitted a small plane with wing de-icers, it would also need pro de-icers, which are either alcohol squirters or electrical heating elements, either of which are quite expensive to install and maintain. I'm guessing by this, you mean deicers for the propellers. Why wouldn't you be able to use the same system for deicing the props? All you need to be able to do is make the leading edges of the blades electrically conductive, it isn't already.

Same story here in 2002 (1)

shotgunefx (239460) | more than 8 years ago | (#15138679)

Similar articles have been posted on slashdot about his work over the years.

Here's one from 2002.
http://science.slashdot.org/article.pl?sid=02/12/2 7/226221 [slashdot.org]

There was another one from I believe 03 or 04. Talking about slip/grip tires and using pulses to defrost electrical lines.

Cool stuff if it works.

Winter: preparing us for the final frontier (1)

John Guilt (464909) | more than 8 years ago | (#15139262)

Every winter, as I survey the masses of snow that have just thwumped down on our grounds and exterior stairs, I remember my implicit assumption that the phaser was initially developed as an ice and snow clearance tool---hit the right resonances all at once, and the stuff sublimes away, or maybe goes directly to a plasma.....
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