High-Speed Sailing

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 [...]

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/

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 [...]

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 [...]

How Fast Can We Go??

09 September 2008

In my last post we saw how a land yacht could equal the wind speed with the sail set at 45 deg. to the length of our yacht (wagon) providing we had 100% efficiency. If we rotate our plywood sail to an angle of about 27 deg. to the length of the wagon (sheet in) and go sailing down the intersection as before, let's see what happens. Once again the wind is 10 knots and 90 deg. to our progress which is also 10 knots. Like before, the balloon will just touch the leading edge of our sail when we intersect its path. However since the rest of our sail is now rotated closer to the oncoming wind, it will not get out of the way of the balloon fast enough and the balloon will bump the sail firmly. This bump will accelerate our wagon faster. At a 27 deg. angle we will go twice as fast as the true wind and once again the balloon will just graze our sail as we pass it in the intersection. Now the balloon appears to be coming at us from a 27 deg. angle (apparent wind) but once again if we look down at this from above, we will see the balloon go straight through the intersection, just grazing the whole length of our sail, while we sail through at 20 knots.

Naturally, instead of one balloon, the air is filled with balloons and these balloons keep striking our sail, accelerating our wagon until our speed is fast enough that the balloons barely touch the sail as we cross their path. If you think about it, you will notice that (at 100% efficiency) our speed is directly related to the angle we set our sail and our speed potential would be almost unlimited!

I will discuss our speed potential in the real world as I continue.

Bob

Comments

Gallery not available

About & Links

Main Page

Send Email