wrote in message
oups.com...
A question sometimes asked is that if you have a large fan at the
stern on a
sailboat blowing forward into the sails would that propel the boat
forward? The usual answer given is no because the fan blowing air
forward would produce momentum propelling the boat backwards. This
would swamp the effect of an effective wind acting on the sails.
But suppose instead you had the fan in front blowing rearward into the
sails?
In this case the momentum would propel the boat forward. Furthermore by
using the method of tacking into the wind, the wind blowing into the
sails could produce a force with a forward component as well. Then the
acceleration forward should be higher than that produced by the
momentum flow of the fan alone. The speed could also be higher than the
speed of the air created by the fan since tacking into the wind can
give you a higher speed than the wind speed.
Would this work?


Bob


Okay, here's what you do:

Install a high-efficiency air compressor belowdecks. Connect this to a
modified luff foil into which precisely sized holes have been drilled at an
angle which allows for maximum efficiency of turbulated airflow across both
the back and front of the sail, with the speed at the back being greater
than that at the front (precise differential you will have to calculate
yourself for your specific sail). Do this for all sails. Report back. :-)

Karin Conover-Lewis
Rawson 30 ketch "Escapade"
Marinette WI