On Feb 23, 2:35 am, Buy_Sell <werksp...@[EMAIL PROTECTED]
> wrote:
> I got thinking again about how to make a hovercraft very, very quiet
> yet still have substantial speed. When I was researching for a small
> lightweight boat, I came across a relatively new idea that I had not
> seen before. This guy has developed a pedal powered boat that moves
> fins back and forth under water. He claims that it is much more
> efficient than propellers. There are several videos on the internet
> about this system and it seems to work quite
well.http://www.youtube.com/watch?v=VljpEpjVdtshttp://www.youtube.com/watch?v=nmSfqAEp44A
> Well, the thought is that I wonder if this sort of system could be
> applied to flight thrust? (i.e. the flapping of wings)
I've seen that guy. Whether it's more efficient or not remains to be
proven in my opinion.
Leonardo da Vinci did that, but it didn't work with the materials of
the time. It's called an Ornithopter. This idea is fantastically
popular in science fiction, and you can actually buy a fully
functional remote control model of one at any hobby store, they
generally look like birds. I spent a year or so of my childhood being
fascinated by the idea.
One drawback I can think of is motion sickness.
Speaking to feasibility though, all I can say is that the speeds he
needs to move his fins back and forth is fairly low, where getting
ample force from an air-type fin might be harder. You might also have
to deal with creaking and whatever, because in trading off of speed
you inevitably increase the force on the part.
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