Friday, March 6, 2009

Moth Midwinters

Just back this week from the Moth Midwinters (20 hour drive down and 30 hour ride back home through a snow storm). We had a small fleet (Only 3 Boats) but had a great three days practice before the regatta where we all were able to try some new things. Most importantly for myself, I was able to try the V7MH design which is the same sail that Nathan won the Australian Nationals with. The sail setup great on my CST 352 rig, but I am looking forward to giving it a try on the Southern Spar as soon as it arrives.

In other news, the 1st batch of V8 sails left for AUS, although they just missed delivery for the Adelaide International Regatta. Hopefully we will have news to report on the new designs next week. We will then go straight into production of the V6 and V10 designs.
Also note that there are two V7 AP designs left for sale. Please drop me a note if you are interested. One sail is unused and the other only used three times. These would be good sails for larger or stronger sailors with a standard bladerider rig, Fastacraft Mast, C-Tech or a CST 351 mast.

Details will be announced for the Volvo Ocean Race Moth Expedition regatta in Boston next week. Posibility of a dozen boats making it the biggest event on the East Coast to date.
Enjoy the pictures from testing before the midwinters. As always, hospitality in New Orleans was once again amazing. Next years regatta will be Feb 17-20th.






3 comments:

nick flutter said...

hi chris
just wondering if you've ever modelled the effect of the leward wing tramp on the tip vortex below the boom, like going upwind?
is there a benefit to closing the gap somehow, like on a sailboard?
cheers
nick

Chris Williams said...

Hi Nick, Currently we are using a Vortex Lattice code for the CFD. I am not sure how much effect closing the gap would cause.

In practical terms I know that in the lead up to the 2003 America's Cup TNZ tried an experiment to seal the mainsail to the deck with sheets of plywood. I've been told that this had no noticeable difference in performance. Obviously a Moth is a different beast than a 25 ton AC Yacht, but the one thing AC teams are good at is picking up little effects such as tests like this. Unfortunately on the way in from this test a friend of mine was badly hurt when the plywood flew off the deck of the tender and into his face!

Other tests (In RANS) have showed a 4% improvement in Driving Force due to sealing a genoa or jib foot to the deck. However, I doubt that you would pick this up in two boat testing even though the difference in predicted driving force is pretty high.

The point being sometimes the theoretical effect of a change such as endplate is high, but reality is bigger gains can be made in having a boat which is easier to sail.

Thanks for the question, the short answer is that I have not and am only using CFD to test ranking of sails and to help model different masts and sails- IE not for absolute performance, such as coupled with a VPP (Not yet at least).

Marcel Herrera said...

Hi Chris,
I am interested in one of the two sails you have for sale still, I am on a limited budget though, taking that they are still for sale, how much were you asking? are they prototypes?
cheers
Marcel