High-Speed Sailing

Vessel Name: Sailien
Vessel Make/Model: Experimental/custom
Recent Blog Posts
28 September 2013

The America’s Cup

I watched, with interest, the videos of the 34th America’s Cup. At last we have fast sailboats engaged in a competition that is fun to watch. The virtual images (such as course boundaries, distance grid lines, separation between boats, etc.) overlaid on the real images really helps to keep the race [...]

31 August 2013

100 Knots for Hydroptere?

The latest news from Hydroptere is that they have plans for a 100 knot sailboat. This was posted on 26 Aug 2013, so look for that date at this address. http://hydroptere.com/en/the-news/last-news/

17 November 2012

Aptly named Sailrocket, blasts off!

While yet to be ratified, Sailrocket posted an average speed over 500 meters of 59 knots. I will not be surprised if they increase their record into the 60 knot range during this record attempt.

02 January 2012

More drag for VSR2?

I want to start by pointing out that the whole VSR2 team has done a stellar job and has demonstrated conclusively that the forces that drive a sailboat can be aligned for roll stability without using ballast and without using any down-force. (Trifoiler achieved roll stability by using down-force, but [...]

18 December 2011

My analysis of Sailrocket

I copied a diagram of VSR2 (wing doesn’t show well) and added in the major force arrows that apply. Be aware that these arrows are not correct in terms of scale (length) and some of their locations are guesses, however I believe I’m correct enough for us to learn something about what VSR2 has been [...]

23 October 2011

60 is within reach, what’s next?

I have been watching Sailrocket’s progress with great interest and there’s no question they have a winner. I fully expect to see them reach 60kt in the near future. Sailrocket has now demonstrated what I first learned with my models and again with my full-sized prototypes, that if you get the forces [...]

50 knots, Comming up?

25 May 2008
I've been watching the Hydroptere website with great interest recently as they have re-launched and are getting ready for some fast sailing. I'm expecting to see some real speed from them; initially it will be unofficial but we will get to see what they can do. I'm giving them a good chance to break 50 this time around, barring unforeseen events.

My reasoning goes like this: They have already run well in the 40 knot range while in fairly rough seas. No other current contender could do as well in those conditions. Their advantage is size (bigger is better in rough water) and their hydrofoils, for the most part, kept the rest of the craft out of the water. They have moved to an area that they say has smoother water and the winds they seek. This alone will make them faster since the rougher water did slow them somewhat. They have also fitted new hydrofoils and I'm sure they have good fluid dynamics design. If correct, this will improve the lift/drag ratio of the foils, resulting in more speed. One other improvement is fairings to reduce wind drag on some parts of the craft, which again will help increase speed.

Naturally I am purely speculating, since I don't know exactly what they are actually doing. However, they appear to be addressing the right issues and if they have calculated correctly they will be faster. Earlier I stated that they are at max power when they "fly" the windward hydrofoil; this is still true and I see no evidence they have done anything to increase the power they can use (such as put a bigger gorilla on the windward arm). What they have done is designed to decrease the drag which will allow for an increase in speed at the same power.

The real question is: since the drag goes up as the square of the velocity, have there been enough improvements to get to 50? I have no idea; I'm just giving them the benefit of the doubt. Also it's fun to speculate and cheer any serious contender on, especially when you understand the basic technical aspects of the problem.

Bob
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