Jump to content

Ornithopters


MirceaKitsune

Recommended Posts

This is a device typically seen in fiction. Or if you're like me, you might have actually considered them as a kid. But I'm still wondering about them today, and curious if they're really an impossible task.

 

I'm talking about manned ornithopters, capable of allowing a person to fly and land safely. The contraption is either wearable like a backpack or a light vehicle (similar to a bicycle), and powered by pedaling or using your arms (no engines or electronics). Obviously, they would be for one person only, and useable up to altitudes where low pressure and temperature aren't a biological hazard.

 

Although a fantasistic idea, I'm well aware of the limitations. Unlike birds, people don't benefit from a light body architecture, and are way to heavy to lift off the ground with a simple contraption. The trick is making the device capable to lift its own weight plus the person's weight, by converting a force the person is capable of generating (eg: pedaling). This makes the task even trickier... since typically, the stronger a person is the heavier they are, so the contraption would need to do very much with very little. On top of that, you also need some safety mechanisms designd... so if control over the vehicle breaks or the person faints, they don't just crash to the ground and die or break their limbs. The wings would have to automatically act as a paracture, or glide forward without ever tipping over or going out of control.

 

Still, this doesn't sound absolutely impossible. If you use smart materials to create something light yet resistant, and a very intelligent array of wings flapped by the person's motion, it might just be possible to have someone rise up to an altitude and fly in any direction. In my opinion, this would be more amazing than a good jetpack happening... since jetpacks are much more unstable and require a lot of costly fuel.

 

So do real ornithopters exist in today's world? Could reliable ones be doable someday... even useable in everyday life as a means of transportation? Under what conditions would they be safe also?

Link to comment
Share on other sites

Seems to me the wear-and-tear on parts is problematic and the necessary large wing size makes for an invitation to disaster.

 

UTIAS Snowbird @ wiki(redirect from Ornithopter

The Snowbird is a human-powered ornithopter that was built as a project of the University of Toronto Institute for Aerospace Studies (UTIAS). Snowbird was the first human-powered ornithopter to fly straight and level.[1][2][3] ...

article-1285277864808-0b51b227000005dc-8source

Link to comment
Share on other sites

Ahh... I actually remember seeing the Snowbird in a documentary judging by the picture. Also, the Atlas Human-Powered Helicopter looks amazing, it's impressive to see something like it working!

 

But as expected, both are very large. Easy to see why they're dangerous to use outside of a carefully controlled area, and impossible to get and can keep at home. I wonder if smaller could be theoretically possible someday.

Link to comment
Share on other sites

  • 1 month later...

Flying with little power means flying slowly. For a given lift-to-drag ratio, and little more than the weight of a human, it takes a minimum propulsive force; then the available power limits the speed.

 

If you compare this speed with wind's speed, it tells that human-powered flight demands good weather conditions.

 

Then, a good lift-to-drag ratio results from the very elongated wing shape. Gliders do it, human-powered or solar powered flight exaggerates it. But as weight must be minimum, this results in fragile aeroplanes.

 

Complete crews, instead of one single human with excellent power-to-weight ratio, would improve, as:

- A team aligned in the wind has little more drag than a single person but multiplies the power;

- People spread in multiple nacelles along the wingspan would improve the wing elongation but keep the wing's bending load bearable.

 

Up to now, humans pedal to fly, sometimes with the arms as well (recent helicopter). Rowing may fit human possibilities better. This may combine with an ornithopter better (or not) than with propellers by avoiding a movement transformation. Though, instead of flapping the wings, I'd consider moving two vertical fins, like a steering oar. Encasing fixed horizontal fins can improve the end vortices.

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.