d1 said...
On a more practical note, I suspect that some aircraft technology will eventually filter through and modernize sailing. For example, there can be passive stall indicators on the sails allowing for optimum in-sheeting. The board can have active canards to adjust the attitude (roll, pitch, yaw) while sailing. The GPS unit can project the speed and bearing on the sail (like a HUD). The boards can have active rockerline (straightens and flexes as required). Lots of scope for improvement, IMO...
Passive stall indicators that allow for optimum sheeting angles already exist. They give precise real-time indication of boundary layer flow characteristics through a 1:1 visual interfacing link. One beauty of these amazing devices is that you can fit dozens on them on any foil, at any place on the foil, so you can use them to monitor twist and draft anywhere. As NASA says, these amazing things show "regions of strong cross-flow, reverse flow, or flow separation" and "regions of unsteady flow".
These amazing high-tech devices are...... bits of wool or dacron stuck to a sail and called tufts!
Sailors seem to assume that aircraft wings are vastly better than sails, but top aerodynamicists don't always agree. Mark Drela is a professor of aero and MIT and his designs hold the world records for human powered flight and water speed. He also helped design the America's Cup wing.
As Mark said once;
"Sails are wings in that they must provide lift with a minimum of drag,
but
their design and operation is much more complicated. There are many constraints, the major one being a maximum heeling moment the
sail can be allowed to generate (analogous to limiting the root
bending moment on a glider). Exceed this and the boat falls over.
This is mainly what limits the sail's aspect ratio.
On an America's Cup boat, each sail's shape can be altered considerably
in many different ways by pulling on control ropes.
Angle, twist,
camber magnitude, camber distribution, are continually adjusted
for each sail by a dedicated crew member.
Makes a glider's trim
flap look kinda trivial." ((My emphasis)
We could make the advances you note (of course, old poly boards had rocker lines that could be adjusted on and off the water!) but maybe we shouldn't. As Mark Drela (who is also an active participant as well as a designer) notes, there's a lot more to making good sporting equipment than making it faster - convenience, accessibility, tactical aspects, feedback etc are more important.
I really wish to see how our windsurfing gear looks 100 years from now.
:
