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Human-powered Helicopter Fails to Lift Off
Peter writes "The Human-powered helicopter didn't even get off the ground. A team of University of British Columbia engineering students tried to win the $20,000 US prize offered by the American Helicopter Society. Three metres off the ground and hover for a minute was the challenge. But before the rotors were able to produce enough buoyant force they hit each other. More details: Vancouver Sun."
Does this mean Lance Armstrong will soon become an astronaut?
I've seen machines in the past that are glider-based, and a human could actually keep them in the air for a fairly long time. But a helicopter? I wonder what they're trying to accomplish here. I mean, obviously the students are trying to win $27,000, but I have to wonder what the American Helicopter Society is thinking. Vertical flight always consumes a heck of a lot more energy than horizontal. I'd like to see more effort put in to human-powerd glider projects.
But God demonstrates his love for us, in that while we were yet sinners, Christ died for us - (Romans 5:8)
The point is that this type of research could lead to more efficient lift mechanisms for conventional aircraft. Allowing longer flights with less fuel requirements.
BTW, the Australian Parlament(sp?) past the free trade agreement, so we now have software patents, yay!
it is only after a long journey that you know the strength of the horse.
IANAAerospace Engineer.
From reading their Project Status/Schedule page, it appears their problems may have arisen during the manufacturing stage:
July, 2004
It has been a while since our last update. We have been busy.
COMPOSITE SPAR MANUFACTURE/TESTING
All spars have been cooked including the tapered sections. Assembly of all this is complete for the four wings. Static testing was carried out for the assembled spars. All four eventually passed the test (see Thunderbird Projects - Picture gallery).
WING CONSTRUCTION
All four wings (for the two rotors) have been completed. This includes all wing parts (leading edges, trailing edges, suction side,
"Eventually passed the test"? Uh oh.
[There were no updates from December 2001 to July 2004]
December, 2001
COMPOSITE SPAR MANUFACTURE/TESTING
Static testing has been carried out for the CFRP spars. Static tests included both bending and torsion. A large effort was put in manufacturing the tapered mandrel for tapered composite spar production. One tapered spar has been manufactured with disastrous results. The tapered mandrel still requires some work (modifications). Composite spar manufacture continues (including straight sections).
It appears there were construction issues early in the project.
I am certainly not knocking their efforts. However, even the most elegant design can be compromised by sub-optimal manufacturing/implementation resources. I wish them the best in the next iteration.
I want to drag this out as long as possible. Bring me my protractor.
The human body constantly generates an approximate 200 watts
You mean the average human...
Lance Armstrong can sustain power outputs around 600 watts, and several people (most competative amatuer cyclists) are capable of a ~1 minute burst of over 1250 watts.
"I'll have a Guinness, no wait, make that a Coors Light" -Grad student I work with, who shall remain anonymous...
I was a member of a team way back in around 1993 that was going for the Sikorski Challenge, which I believe was similar to this one. At the University of Illinois at Champaign-Urbana our project, named the X-391 Dragonfly, was to hover at 1 meter for I forget how many minutes. We got as far as building the main rotor from carbon fiber/kevlar/foam injection with a custom made oven/vacuum bag contraption as well as designing the 'cockpit' the rider would sit in. It was a great experience even if it never "got off the ground" pardon the pun.
You are only popular on the Internet.
"the atmospheric conditions caused a dangerous imbalance in the craft's two rotor blades: the bottom blade was producing lift while the top blade wasn't." Sounds to me that what really happened was that they tried to save weight and didn't make the upper blades, which are longer, torsionally stiff enough. This caused a phenomenon similar to aileron reversal: as you produce lift, you produce a nose-down pitching moment which can elastically twist the blades, and may be capable of reversing the direction of lift. If this is what happened, then I can easily see the upper blades flapping down into the lower set of blades.
This aileron reversal effect is actually a fairly hot research topic in the rotorcraft community. People are trying to exploite it by using embeded actuators to control trailing edge flaps to create a pitching moment to twist rotor blades and thereby eliminate the swashplate for primary control.