
A new way to remove ice buildup without power or chemicals - dnetesn
https://phys.org/news/2018-08-ice-buildup-power-chemicals.html
======
oh5nxo
Not directly related to ice, but...

A fellow lives near a new wind farm, and a TV transmitter. Both the windmills
and the TV tower are in direct view. He, and I assume also others on that
area, have had great trouble receiving a good picture. Even the technicians
from the broadcasting company are scratching their heads. 100m rotating blades
create awful changing reflections.

It would help if the blades were coated by some absorbent material. Just the
sharp edges, if the material is too costly.

The defence forces have even banned wind farms from certain areas, I read on
the papers last week. Too much interference on radar.

I don't know what the current situation is with fellows TV reception. I assume
careful aiming of TV antenna has helped.

~~~
gravypod
There are a few companies that specializes in removing that noise from radar
systems used in planes. Apparently it isn't easy.

You might try and look for a ground wave vhf antenna and see if you can pick
up something from the TV station. 100m is very close

------
userbinator
_The top layer is an absorber, which traps incoming sunlight and converts it
to heat. The material the team used is highly efficient, absorbing 95 percent
of the incident sunlight, and losing only 3 percent to re-radiation_

Is there anything to prevent the surface from getting _too_ hot? Solar is
powerful, but as anyone who knows of the dangers of fresnel lenses and
magnifying glasses can tell you, it can sometimes be _too_ powerful.

~~~
analog31
The good news is that the heat isn't concentrated on a single spot, it's
spread out quickly over the surface. In contrast, a lens concentrates the
light to a small spot. It's the localized heating that causes things to catch
fire.

And the heating isn't a one way street. It's either converted to the melting
of the ice, or re-radiated at longer wavelengths.

------
adrianmonk
That layer of insulation seems like a double-edged sword. It would keep
incoming heat from being wasted on the interior, but without it, the internal
heat of the object can keep the surface from freezing as quickly.

So, for example, if an object is moved entirely into the shade for 10 minutes,
perhaps in certain cases without the insulation it would not freeze but with
the insulation it would.

Also, it might be harder to use an internal heating element for the cases
(like night time) where the solar approach isn't good enough.

------
sinab
This is pretty cool, I wonder if this could be used on roofs in places where
ice dams [0] are a big problem.

An alternative and cheaper system which my team and I developed in our
undergrad senior capstone was to use drip irrigation mounted to roofs (and
organic deicing fluid) to mitigate ice dams. This was accomplished by dripping
fluid down the roof to "cut" channels into the ice dam to allow the water
built up behind the dam, to drain off of the roof. I think you could possibly
do something similar by placing strips of this 3-layered material vertically
oriented on a roof to melt channels in the ice dam..

[0]
[https://en.wikipedia.org/wiki/Ice_dam_(roof)](https://en.wikipedia.org/wiki/Ice_dam_\(roof\))

------
baybal2
At power output produced by APU of a large airliner, electric deicing looks to
be almost free.

For smaller planes, things are different. Pneumatics is an acceptable
compromise, and piezoelectric that is soon to come to the market will have
almost no flaws besides the upfront cost.

------
DoctorOetker
From a thermodynamic perspective, roughly speaking fuel based engines convert
the flow of heat from a high temperature heat bath to a low temperature heat
bath into work. The higher the difference between the temperatures the more
work can be extracted. It would seem to me that _in theory_ the vehicle
surface area could be used as the colder heat bath for improved efficiency.

I am not claiming any actionable specific device or configuration design to
improve the efficiency though!

------
zrm
Would this work to deice heat pumps in winter? There are obviously some
factors working against it (low temperature, shorter days), but maybe with
enough surface area?

------
WhiteMonkey
Would these layers be thin enough to be translucent?

~~~
analog31
My thought is that in order to be thick enough to absorb sufficient sunlight,
they also have to be thick enough to look black.

------
plantain
Not so useful if your airliner flies at night as well

~~~
serpix
Or above 50degrees latitudes

------
aldoushuxley001
That's actually incredibly useful. The aviation industry and any pilots must
be stoked.

~~~
petermcneeley
This probably wont work well if all in cloudy days or with any kind of
snowfall (due to very low amounts of incoming irradiance). Also, just the
aluminum coating in this 3 layer material weighs 586 kg for a 747 wing area.

~~~
neltnerb
Wow, that does seem like a huge amount. On the other hand, 184,567 kg is the
empty weight so it's "only" a 0.3% increase. Maybe not so bad since they don't
need to carry deicer anymore?

~~~
cpncrunch
They dont carty deicer anyway...they use bleed air from the engines.

