BoatBanter.com - View Single Post

On 30 Mar 2004 00:17:24 GMT, (JAXAshby) wrote:

steve, consider just where the air on the "supply side" of the fan blades come
from and consider how that differs from the air on the "demand side". the
demand side is more or less a stream that expands. the supply side is more
like a hemi-sphere of air (actually, air from the demand side passes back to
the supply side as each blade of the fan passes, i.e. tip vortices).

Consider that it doesn't really matter as long as there is flow of fluid
media over the rudder.

Consider, also, that *if* fluid drawn over a rudder by a prop have any effect
on the rudder, mariners would all know which direction the stern moved with
which rudder position. Even the guys who insist pulled water affects a rudder
don't have a clew which way the boat turns. indeed, the "good professor" was
reduced to claiming that friction in the rudder bearin made the difference.

Consider the fact that fluid drawn over a rudder by a prop may have an
effect on how the stern moves, but one that is much less then prop walk.

Steve