Human-Powered Flight

[flying saucer]

This is a terrific old school documentary called "The Light Stuff". A team tries to build a human powered aircraft capable of travelling between two points in Greece. The planning and preparation is really amazing. Also love the line the narrator uses at the end. 

Here is part one:

Part 1 NOVA The Light Stuff (human-powered flight)

You'll have to find each successive part in the related videos..

[pmackenzie]

Very cool.
I remember this well from when it was on TV.

The "chief aerodynamicist" Mark Drela is a well known modeller.
He is responsible for three of the most influential glider designs ever: the Supra for F3J, the Super Gee for Discus launch and the Bubble Dancer for RES.
The Ava is essentially a commercial version of the Bubble dancer.
Plans for all three, and several more of his are available on the Charles River web site:

http://www.charlesriverrc.org/articles.htm

Well worth looking over to see how the structure has been optimized to the task at hand.

The program they mention in the video for designing the airfoil became X foil, which is used by just about everyone these days to design new wing sections
http://web.mit.edu/drela/Public/web/xfoil/

With Xfoil the wing can be completely optimized for chord, twist and airfoil. There are different airfoils as you move from root to tip.

Pat MacKenzie

[piker]

I'll take a look at the video a bit later today, but in the meantime I wanted to share what I was doing on Friday afternoon.

There's a group from U of T that are going for the AHS Sikorsky Prize that requires a 60 second flight with 3 metres altitude reached at some point during the flight, AND while staying within a 10 metre box with a HUMAN POWERED HELICOPTER!  The guys are very close, and I was there on Friday as they had planned to go for the record.  Didn't happen, but they're very close.  I wouldn't be surprized is they go for it this week.

Atlas Trimming Flight: 5 feet, 30 seconds

These are the same guys that built the human powered ornathopter:

http://www.aerovelo.com/gallery/featured-videos/

We (Cervelo) are interested as a sponsor.  They're using our lightest bike frame for the bike part of the helicopter.  We are also helping them with some computational fluid dynamics analysis for the human power vehicle (ground) that they're working on to set a new speed record in that discipline.

BTW, when I arrived at the flight test site on Friday, Jack Humphreys was there.  As it turns out, he's the official deligate to the FAI to observe the record attempts.  There's also the FAI duration record available which currently stands at 65 seconds, I believe.

Here's the site for the U of T guys:

http://www.aerovelo.com/

Oh, and Mark Drela has created some airfoil sections for Cervelo in the past for things like forks, seat stays, etc.  They're intended to work with the airflow interactions around the spinning wheels.

Robert

[flying saucer]

Good info guys, also good to see these types of achievements and challenges are still up for grabs and being pursued.

With all the advances in materials and design, the human powered helicopter does seem a bit dated and clumsy to me. I would've looked into a much smaller, higher rpm 4 rotor design that has more mass (and therefore momentum).  Almost like an exercycle at a gym, give it the beans for a second or two and it winds up to a good speed and keeps spinning. Then perhaps employ some type of variable pitch device to change the AOA of the rotors.

[pmackenzie]

If you know a bit about momentum theory of propulsion, bigger is the way to go for efficiency.
A smaller rotor will require much higher velocity of the air being pushed down for the same thrust, and the energy in the flow is lost.
Plus you will have ground effect benefits with such large rotors.

Rob, how are the controls done? Are they using the little "elevator things" at the tips to twist the blades to change pitch?
Is it all electronic?

That Drela is a busy guy.
I have some data on a human powered boat prop he designed that I carved the plug for.

Pat MacKenzie