
An airfoil that will never stall, no matter the angle of attack - andrewfarah
http://www.propulsivewing.com/
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awjr
Rather than kill the site (as the video is a downloadable 27mb file), I've
uploaded it to youtube
[https://www.youtube.com/watch?v=frgCQVGOdgs&feature=youtu.be](https://www.youtube.com/watch?v=frgCQVGOdgs&feature=youtu.be)

I'll delete it in a couple of days once this drops off HN.

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simonblack
There is a difference between stalling due to high angles of attack, and
having too much drag from cross-sectional resistance on an unstalled wing to
be able to lift. The practical outcome is the same however, not enough lift to
overcome the weight.

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Alupis
Or not enough airspeed, which is the most common stall condition real pilots
face (caused by a variety of scenarios such as too much altitude, runway
approach too slow, etc).

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Aerohead
Hey guys, I worked on this program as an intern in my senior year of college
(2012-2013). There are 5 units of the mini-PW's out right now for testing, and
I've built all of them. I can answer any questions you might have and I'll do
my best to explain the aerodynamics behind it if anyone is interested!

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TheLoneWolfling
What does the list-to-drag ratio versus AOA curve look like?

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TheLoneWolfling
*lift, sorry about that.

And I'd actually be interested in both the lift curve and the drag curve, as
well as lift/drag.

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AlexeyBrin
The title is a bit sensationalist - _An airfoil that will never stall, no
matter the angle of attack_. They did CFD simulations that _shows_ their wing
not stalling at extreme angles of attack (not at any angle).

Also, they are talking about a _wing_. An airfoil is a wing section not the
actual wing.

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ibisum
An airfoil describes the stall characteristics of the wing.

Camber, chord, edges, angle of attack .. these are all described by the
airfoil and are key to flight control, including stall handling. How an
airfoil gets itself out of the stall state is of great interest to designers.

Airfoils which utilize the Magnus effect (as in this case) do have different
stall characteristics. Its not incorrect to refer to the airfoil in that
context.. a bit like calling a soccer ball not just a sphere but also a wing,
too, which in fact it is to most airfoil designers .. ;)

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callesgg
Not entirely correct as turning it over 90 degrees does not apear to work.

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fit2rule
I'm reminded of some of the other attempts to utilize the Magnus effect:

[https://www.youtube.com/watch?v=kgOAwzG9Fd0](https://www.youtube.com/watch?v=kgOAwzG9Fd0)

[https://www.youtube.com/watch?v=_BDCcSR1pJ4&list=PLB851DC7DF...](https://www.youtube.com/watch?v=_BDCcSR1pJ4&list=PLB851DC7DF2995130)

[https://www.youtube.com/watch?v=acXvl-8xrBM](https://www.youtube.com/watch?v=acXvl-8xrBM)

Very interesting flight mechanics are possible when designers try to utilize
this effect, and its exciting to see this little-known technology come to the
forefront as more and more folks enter the 'drone-fleets are the new network'
age ..

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ridgeguy
This reminds me of the Boeing YC14 blown wing (1). It looks a little like a
fully structure-contained implementation of that concept.

(1)
[http://en.wikipedia.org/wiki/Boeing_YC-14](http://en.wikipedia.org/wiki/Boeing_YC-14)

~~~
Crito
Kind of reminds me of a lot of ekranoplan designs.

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larrydag
I wonder how it performs when there is power failure? Does it glide well?

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Aerohead
Absolutely not. To glide well, you need big ol' wings. There's a concept
called aspect-ratio, which is basically the relationship between the wingspan
(left to right) and wing chord (front to back). High AR = better for gliding.
Conversely, and in the case of the mini-PW, when you have virtually no
wingspan, you aren't going to glide very far. We affectionatly referred to
power loss as "brick mode".

~~~
larrydag
So i suppose you could design a trade-off or balance. Increase AR while
reducing the size of the mangus effect airfans.

~~~
Aerohead
Well ideally we wouldn't lose power to begin with but yes. The PW is
essentially a powered wing to begin with, so losing power leaves you with just
a wing. The real design benefit here is that with the powered wing, you can
make the win extra thick. And I can tell you, that internal space is huge.
Plenty of room for any kind of payload.

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lotsofmangos
Cool, is fairly similar to the fanwing configuration.
[http://www.fanwing.com/](http://www.fanwing.com/)

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staz
Could a (2010) be added to the title? The website don't seem to have been
updated since then

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Aerohead
The website hasn't been updated in a while, but I assure you that development
is still going on.

