A New Way Forward for De-Ice?

[Rotorhead]

Check this video out. I wonder what the practicality of having this type of 'heated pipe' in the leading edge to act as anti/de-ice would be? Albeit probably expensive, it seems as though it wouldn't take too much more power than 20A across both wings. Although it would add weight, I would assume it would be marginal compared to the TKS at ~9.2lb per gal. Also, I imagine the upkeep would be considerably less as long as it has allowances to move with the wing in flight.

Seem to be too good to be true? Either way, pretty cool nerd stuff.

What's Inside the Worlds' Fastest Heat Conductor? - YouTube

[GeeBee]

It is cool stuff but the laws of thermodynamics and heat conductivity cannot be repealed. It takes huge amounts of heat to de/or anti-ice a wing. Even 20 amps at 24 volts is 480 watts of heat. In SLD that would not cut it for a second let alone 30 seconds to get out. If you look at most jets, they are running 400 degree air out in 4 inch ducts to the wings at 30-50 psi. Think about how much heat that represents. I have to say most people underestimate the amount of heat required in icing conditions. I've flown in conditions where windshields with continuous 120 volt heat thermostatically set to 90 degrees have gone opaque from ice.  If you ran these pipes, while it is an excellent heat conductor, the aluminum wing would have to absorb the heat and radiate it across its entire area, a huge radiator, unless you put in an insulated leading edge. With that then you have the problem of "run back", that is water running off the warm surface onto a cold soaked structure. With TKS you have the advantage that the TKS fluid is running back across the wing and protecting a large portion of the structure.

I have to say, not having flown TKS until my Mooney, and having flown boots and magnificent bleed air systems coming out of 80K of thrust (each side), out of arctic airports, I am highly impressed with the TKS system. Yeah the fluid is a little heavy, but its coverage and effectiveness is way better than boots and the run back problems with bleed systems just does not exist if you operate the system correctly.

 

[carusoam]

From an ordinary PP’s point of view... (pure humor follows...)
 

Congrats on finding a technology with a very cold future...   

Aluminum makes a pretty good conductor too...

Copper makes a better conductor than aluminum in case we want to make some experiments....

If we took a strand of copper and coated it with a plastic layer, like insulation... we could deliver magical energy from a source near the front of the plane.... then we could distribute that energy at the molecular level, all over the place.... (more on that later)

Big challenge....

Our whole plane is made of very conductive aluminum... yet we still get ice...  

 

By watching the video, the pipe could transfer energy at about 10X the rate of copper...

What is missing is the giant source of heat energy... it takes a lot to warm the leading edge... and all the stuff that impacts it...

Let’s say you had a big heat pipe that took the heat energy from the oil cooler and piped it to the wings instead....

Then you might realize... all the ice you melted at the leading edge ran back and re-froze a few inches behind the leading edge...

Thinking forwards a bit more.... eureka! You could build a whole micro-network of heat pipes... on the wing....

 

Hey wait a minute....

If the heat got there in 30 seconds instead of three seconds... what’s the big deal..?

The heat pipe delivers heat quickly from point A to point B...

• it doesn’t generate the heat...
• it doesn’t distribute the heat...
• it doesn’t keep the melted ice from re-freezing...
• it doesn’t even keep the heat from leaking out the side of the heat pipe...
• 

 

Now, compare to TKS...

• A concentrated anti-freeze gets distributed at the front of the important surfaces...
• The anti-freeze gets diluted as it runs back and continues to melt ice, and keep ice from sticking and forming to the surface...

Or conductive surfaces....

• Lots of electricity required...

Wait there’s more...

What if we used a highly resistant material like a ceramic coating?  Could we get the wing warm enough in the hangar that ice wouldn’t want to form on the wings? (Technical dead end)

or... that same ceramic coating not only caused a deep shine to the paint, it formed such a smooth surface... the ice couldn’t stick... (interesting possibility)

 

It’s Friday... and these are only PP ideas.... discuss at your leisure... 

It’s going to take a few good ideas working together to keep ice from forming on the airplane...  similar to a few good ideas that it takes to keep from running out of fuel...

What other ideas do we have to move this technology forwards?

Best regards,

-a-

[N201MKTurbo]

We have had good ways of moving heat around for a long while, when it comes to de icing with heat, the problem is generating the heat, not moving it.

Edited December 7, 2020 by N201MKTurbo

[EricJ]

Heat pipes have been around for a long time and have been used in electronics to conduct heat away from critical components for at least 35 years.   In the late 1980s A manager of mine tried to get a sample (made from aluminum, but looked just like the one in the vid, otherwise), from one of our vendors and give it as a present to another manager we didn't like very much and tell him it was a coffee stirrer.   Unfortunately we were unable to secure a sample at that time. 

As mentioned, they're just good at conducting heat, they don't generate it.   You still need a lot of heat generated somewhere to warm things enough to prevent or remove ice.    In jets/turbines this is often done with bleed air.   In WWII some aircraft used portions of the leading edge for intercooling.   On a small aircraft there's typically not a lot of excess power available to thermally de-ice, so chemical (TKS) or pneumatic (boot) systems are used instead, which require far less input power.

[exM20K]

1 hour ago, GeeBee said:

It takes huge amounts of heat to de/or anti-ice a wing. Even 20 amps at 24 volts is 480 watts of heat

The electro-thermal system in the early Columbia planes was a failure IIRC because of the alternator size and reliability requirements.

I too prefer TKS to boots.  I hate vacuum pumps. They fail, and if steam gauges and boots in IMC, you’re right properly screwed.

-Dan 

[jaylw314]

1 hour ago, GeeBee said:

It is cool stuff but the laws of thermodynamics and heat conductivity cannot be repealed. It takes huge amounts of heat to de/or anti-ice a wing.

The thing is, we have a constant source of 1400 degF heated air coming out the exhaust valves of our motors.  I imagine that's plenty to melt a thin layer of ice on the wings.  Of course getting that heat to the right place safely might be a wee tricky...

[carusoam]

Getting the excess heat away from the exhaust valves would be nice...

We currently use oil to do that...

Some of the heat transfer is limited by the valve’s stem...

 

Some fancy valves use Sodium filled stems to help with the heat transfer up ...  sounds like a turbulent heat pipe sort of... 

 -a-

 

 

[Scott Dennstaedt, PhD]

On 12/4/2020 at 8:34 PM, EricJ said:

Heat pipes have been around for a long time and have been used in electronics to conduct heat away from critical components for at least 35 years.   In the late 1980s A manager of mine tried to get a sample (made from aluminum, but looked just like the one in the vid, otherwise), from one of our vendors and give it as a present to another manager we didn't like very much and tell him it was a coffee stirrer.   

I have an ice cream scoop that uses body heat in a similar way. Hmmm?  I think I'll try it out after dinner tonight! 

[carusoam]

Scott is not only a brilliant weather guy...

That ice cream scoop could be greatly improved by this technology..!

We have the heat in our hands, and more in the water faucet if needed....

Just, the aluminum scoop in its current cast aluminum design can’t deliver the heat fast enough to the tip of the scoop!

The heat pipe could be gigantic for the ice cream scoop business... 

 

Anyone have a number for that scoop factory?

When you see the Dennstaedt Scoop in every ice cream store... remember, it started here on MS in 2020!

The second best part... No STC required!

Best regards,

-a-

[aviatoreb]

Isn't forced excess heat the basic idea behind de-ice already used in large jets?  But that this mostly does not work for the smallest of the corporate jets because there just is not enough excess heat - eg the cirrus jet uses boots?  Or was it tks?  And certainly here is not enough excess heat in piston engines.  Temp is not the relevant number.  BTU is., isn't it?

E

[GeeBee]

BTU's/min

There is not a lot of excess heat in bleed systems either because you are taking that heat from the compressor which diminishes overall thrust. For instance, the DC-9/MD80 series does not have sufficient bleed capacity to protect both the tail and the wings at the same time, so it uses a timer to direct back and forth.  Newer engines have a more compressor capacity and do better, but nothing is free. Next ask about "Enroute Icing Correction" for Boeings because the vertical stab icing.

 

 

 

[Awful_Charlie]

Remember Thermawing? Never really took the market over despite the promises, and needed an additional 7500W (that's 300A at 28V) alternator

Edit: 2008 Aviation Consumer review

Edited December 7, 2020 by Awful_Charlie
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[EricJ]

3 hours ago, aviatoreb said:

Isn't forced excess heat the basic idea behind de-ice already used in large jets?  But that this mostly does not work for the smallest of the corporate jets because there just is not enough excess heat - eg the cirrus jet uses boots?  Or was it tks?  And certainly here is not enough excess heat in piston engines.  Temp is not the relevant number.  BTU is., isn't it?

E

De-icers in turbines that use bleed air take away from the output power, since they reduce the supply of compressed air to the combustor.   So it's not excess heat; you seldom get something for nothing.   That said, bleed air is a pretty efficient way to use available power for other tasks which is why it was used for a lot of things for a long time. 

[McMooney]

I always wondered why not run the exhaust pipes along the leading edges  and against the fuel tanks.

figured you'd have an enormous amount of heat available

[Hank]

21 minutes ago, McMooney said:

I always wondered why not run the exhaust pipes along the leading edges  and against the fuel tanks.

figured you'd have an enormous amount of heat available

Because wet wings leak????

[McMooney]

6 minutes ago, Hank said:

Because wet wings leak????

who knew

[Awful_Charlie]

Well, I suppose an aircraft on fire won't need to worry about the icing aspect

[aviatoreb]

1 hour ago, McMooney said:

I always wondered why not run the exhaust pipes along the leading edges  and against the fuel tanks.

figured you'd have an enormous amount of heat available

Besides the fire...

my guess is while it seems like a lot of heat, it’s not enough is my guess.

 

[N201MKTurbo]

Don't you think this would have been tried, like 100 years ago back in the air mail days? Do you all think you are the first to think of this?

[carusoam]

redirecting exhaust?

The thermo dynamics don’t work so well...

Our open ended, short exhaust pipes work really well because they have so little back pressure....

The real benefit... our exhaust pressure goes from high to low in a few inches... the adiabatic cooling that comes with the pressure drop is gigantic...

This is the reason that EGT sensors need to be mounted with precise locations for best data...

If we start adding length to the pipes... the back pressure starts to Rob huge amounts of power...

Add a bunch of insulation.... weight challenge...

 

Or just look at the exhaust pipe on our cars... that far end isn’t hot at all....

Plumbing radiator fluid around the wings Would be interesting for a moment... but re-freezing ends the fun pretty quickly...

PP thoughts only, not an airplane design engineer...

Best regards,

-a-