Standup Zone Forum
The Foil Zone => Wingsurfing, Windfoiling, Wingfoiling, Wing SUP => Topic started by: DavidJohn on December 09, 2021, 04:34:35 AM
-
https://youtu.be/rq0-Txzcsc0
-
This is very cool!
-
I wouldn't want to be inside that thing if the foil were to hit some floating debris.
-
hmmm. I am imagining flukey wind and one giant hindenburg of that kite. How does the re-launch go? One interesting feature is the little bump in the mast halfway down. I wander if this helps keep ventilation from creeping down the mast.
-
Yeah, that looks like an anti-ventilation element. they certainly can't afford to ventilate. They'll be operating at a power/speed level that unquestionably will cavitate. They can design for that since the effects are consistent and relate to how much power they are applying. Ventilation is more chaotic, and would be hard to accommodate. It's a gorgeous idea and could be influential for future watercraft--even commercial transport.
VESTAS Sailrocket 2 actually uses a similar approach, though it doesn't look like it at first glance, but it's a lot more complicated. They went 120 kph (65 Knots, 75mph) last time I checked. I think eventually you have to use a kite to go a lot faster. 150 kph (their goal) is 81 knots, 92 mph. That's going to be really hard to do.
-
The sailrocket blog has a lot of interesting technical information, including this article on cavitation. They appear to have successfully dealt with some of the issues of going faster than 60knots by designing foils that function with cavitation. I imagine that the short record runs help minimize the damage cavitation generally causes. I've seen more than a few pump impellers eaten away by the effects of cavitation, where the implosion of the steam bubbles next to the impeller creates a sonic shock wave that knocks bits off the metal impeller surface. http://sailrocket.com/node/288