On Mon, 22 Nov 2010 08:54:03 -0800 (PST), Joe
wrote:
On Nov 22, 9:40*am, Wayne.B wrote:
On Mon, 22 Nov 2010 07:21:00 -0800 (PST), Joe
wrote:
Now directly couple a motor/generator that consists of a stator
winding employing a high pole count configuration, which allows for
high copper utilization (minimizing energy loss and cost), and a
hollow rotor upon which powerful rare earth permanent magnets are
mounted on the outer circumference coupled to a variable pitch prop
system and you can pump out some serious energy. The city buses that
are using these moters claim they capture 97% of the kinetic energy
developed while stopping.
Regardless of the capture mechanism, even at 100% efficiency, there is
only so much energy in a moving column of water and it is not a big
number when you are moving at sailing speeds. *Now if you could get
that same column of water rolling down the side of a 1,000 ft
mountain, that's a whole different story. * :-)
I'm going to have to disagree with you Wayne. The amount of energy
coming off a shaft at sailing speed can be huge. The drag can be
offset by canvas with ease on a non-planing hull. If you capture 1 rpm
of energy for every 4 rmp's generated by sail, and can store that
energy you have a system that can work.
Now if a bus can capture 97% of the kinetic energy by stopping then
why can't a prop do the same ?
About the smallest CVP system available is in the high 30's low 40"
diameter.
You ever chain down a shaft to a 40" prop? You better have some strong
chain.
http://www.youtube.com/watch?v=6KSnH6DFA94 Not quite a 1000 ft drop
but plenty of power to harness.
Joe
Are you normally obtuse, or have you always gotten your technical
information from the movies?
The Youtube show you recommended states that it is a 200 ton sailing
boat. While your reference doesn't indicate the length of the vessel
but seems to say that they were doing 9 knots.
I found a reference to another 200 ton sailing vessel on the net - it
was 138 feet long. The hull speed for a 138 ft. vessel is about 16
knots so your reference was sailing at abut half hull speed (56%
actually). Hardly impressive.
And, by the bay, how many sailing yachts have you been on that were
fitted with a 40 inch propeller?
Cheers,
Brice