On 30/09/2010 21:37, Rick Cavallaro wrote:
On Sep 30, 12:58 pm, Clive George wrote:
Ignoring Dennis, who delights in proving how wrong he can be on a
regular basis, I have to say I found the explanation of how it works a
bit opaque. I'm pretty sure I've got it, but the text and diagrams
didn't really help that.

Clive, there a a BUNCH of ways to describe what's happening here.
We've found that some people respond to one description and think all
others are nonsense, and others find one of the others useful. We'll
be happy to answer your questions and tailor the discussion to help
bring it across. Just let us know what's making sense and what's not
making sense to you. The energy analysis is very compelling to me at
one level, but it's also useful for me to think of each blade of the
propeller as being on a continuous broad reach - spiraling downwind
faster than the wind.

I prefer working with the forces rather energy - I think introducing
time into it unnecessarily complicates things.

Playing with the dynamics of the propellor also doesn't help me - see
how I've started my own explanation. The propellor comes later.