Showing posts with label quo vadis windsurfing speedsters?. Show all posts
Showing posts with label quo vadis windsurfing speedsters?. Show all posts

Friday, December 5, 2008

Epic high speed freestyle

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http://www.sailrocket.com/live/?q=node/78

Sailrocket is an ambitions project to make an experimental sailboat (I cringe at the term, given that this craft bears about as much resemblance to what I generally think of as a sailboat as a Lamborghini does to a Yugo) go world record speeds. For a long time, there's been an interesting dual development on the speed circuit. 

On the one hand, you've had attempts like Yellow Pages and MI and (significantly larger and more open-ocean oriented) Hydroptere using pretty sophisticated technology and rather intricate and complex designs to balance the physics in an efficiency game - meaning they have tried to  push the boundaries of lift/drag ratios on all foils and played with ways to leverage their righting moment to produce high speeds in reasonably low wind speeds (Sailrocket just produced 52 knot peak speeds in roughly 25 knots of breeze).

On the other hand, you've had the windsurfers and, recently (and with spectacular success) kiters, play a completely different game of simplicity and brute force. Yes, the wipeouts for them have been spectacular, too, but they don't involve a 20 foot craft looping - just a good old fashioned endo or teabagging at very high speeds (and no doubt a lot of pain). Kiters have learned to harness an advantage of their platform, which is that kites generate vertical lift - that allows them to use boards so tiny, they make windsurfers' speed boards (at 45 cm or less width) look monstrous. Pair that with their tiny fins, and they could not only reduce drag, but they could also find smoother water w/o fear of things getting too shallow. Pair that with the geometry of the whole setup giving them more favorable leverage, and it's hard to see windsurfers catching up.

So far, the simple brute force approach has the edge, with Yellow Pages in 93 the only efficiency play in the long list of first windsurfers, then again windsurfers (Maynard and Albeau, really, as they were in a class by themselves), and now kiters that have held the outright record.

What's becoming obvious, though, is that there's a middle ground. The kites are taking a page from the "boats" in that they optimize low drag by employing vertical lift to reduce wetted surface (only, they do it by simply having their kites drag them up while accelerating, as opposed to using hydrofoils to get a hull out of the water). They're also employing leverage for their righting moment - only they do it by decoupling the airfoil from the sailor/craft package via long kite strings as opposed to utilizing outriggers. So they're doing the same things, but radically more simply (and thus, one might argue, more elegantly). Which allows them faster and cheaper development cycles (tuning kites is a matter of a simple recut and some tweaks to line geometry; shaping a new kite board or producing a new fin takes a matter of days and investment in the hundreds of dollars, not tens or hundreds of thousands). 

The kiters have thus managed to push the solution space boundaries by one-upping windsufers on simplicity while at the same time gaining on the efficiency front (note that they're making record runs in lower wind speeds - which means they've got a feedback loop going that gives them more chances at records).  To get another crack at the outright record, windsurfing will have to figure out how to play the efficiency game - but still retain its simplicity (or else it will be cost-prohibitive and run into the issue of slow development cycles that seems to be keeping the boats from keeping up with the kites). That means truly exotic hydrofoils and outriggers and such are probably out. Perhaps launching from a moving boat (to allow for smaller boards) might work (hey, it's what they do with speed record aircraft so they don't have to have big draggy wings); that seems to make the need for super high and consistent winds only worse, however, and will further cut down on eligible venues.  Aircraft carrier-style catapults probably add a bit too much complexity (but might produce some spectacular YouTube moments...).

Fun stuff!

Saturday, October 4, 2008

50.57

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Damn, those kiters really have hit their stride now. At theLüderitz Speed Challenge , Sebastien Cattelan  of France broke the 50 knot barrier. Rumor has it that this means the canal won't open for the next round of Masters of Speed - I could see how that might be true, as it would be harder to get sponsorship together and get people to commit that much time and money if there's no more chance at being the first to break 50.

Congratulations to the kiters at Luderitz - those are some pretty awesome performances. Given how quickly they were able to push their speeds up to those levels from where they were just a few years ago, there's been a lot of very rapid development in that sport. Good on them!

I wonder if this will spell the end of the speed rush windsurfing has gone through in the last few years, with several well-organized record attempts and a bunch of grass roots GPS-based informal competition. I also wonder what it will take for windsurfing to reclaim the outright record - it took Maynard and Albeau a lot of time, money, and R&D to get to 49.09; kiters just blew right by them, and physics seem to be on their side at this point. Seems like the current gear and technique combo needs to be tweaked a bit to get back in the game. The sailors have been trying to do the same thing vis-a-vis windsurfing (check http://www.sailrocket.com/ or http://www.hydroptere.com/ to see some of those attempts - none of them successful so far) Perhaps we'll end up seeing some crazy foiling windsurfers with funky outriggers to get on top of the physics here - but given the state of the industry, I'm not sure where the funding for such extensive R&D would come from. Incremental improvements to the current design paradigm seem to have run into the law of diminishing returns.