its not that ETNZ can’t foil up wind, they can, but the problem is they loose to much ground up wind. IE their VMG with hull in the water and the ability to point higher is better than falling off and foiling. they are trading speed for distance…
they had 2 knots of incoming tide, not the best circumstances to foil up wind.
L.R. did their first tack at the prestart and lost the whole race, chanceless to come back in front.
The time difference at the end of the race was 5 minutes. The winner sailed the course in 43 minutes. Just to show how big that margin is, that same differential in the ACC mono hulls where the race took about 180 minutes, the difference would scaled to over 20 minutes - a horizon job. (5/43*180)
John
Actually:
ETNZ is with 4 wins
LR with 1 win
Artemis with 0 wins
No story about !!!
ClaudioD
neat stats…
LR spotted ETNZ nearly 3/4’s of a mile, 1400 meters over the course. or about 2 minutes
at an average speed of 27 MPH or 1 mile every 2 minutes. LR would have been much closer couple that with her Unforced out of bounds error, and you eat up about 3 minutes of the clock… a poor start…
More time on the water LR will get better, but not good enough…
I think ETNZ has a broom in the closet so they can sweep up…
Any opinion on the [u]Ground Effect[/u] theory that ETNZ possibly have over O.R with their aerodynamic fairings packages ?
Appears possible with ETNZ forward “wing beam” and “foil shaped rear beam” could be flying stability card they have over O.R compared having only two foil shaped beams … ! ?
should have more impact at a close hauled (20 knots windspeed plus 20 knots boat speed).
some of the commentators said, the plate should prevent vortices at the foot of the wing.
[i]'Interestingly, the Italian boat sailed 1376 meters (0.74 nautical miles) further than the New Zealand boat over the length of the race, and most of this extra distance came on the upwind legs.
There was also a wider disparity between distances sailed on each upwind and downwind leg on the Italian boat, suggesting more consistency and smoother sailing by New Zealand.’[/i]
at virtual eye it looked like that ETNZ could go higher to close hauled and deeper to a running than L.R.
maybe thats just the effect of having more time on the water with the boat, you know what it can do
Practice makes perfect…
the plate at the bottom would help with the “end plate effect” a plate on the end of a wing increases the wings efficiency…
Stop traditional sail boats (10 knts) and start thinking slow aircraft flying (50 knts)
Ground effect craft are defined as a vessel capable of operating completely above the surface of the water on a dynamic air cushion created by aerodynamic lift due to the ground effect between the craft and the water surface.
Ground effect has been developed in both fields of aeronautics and marine craft which receive reduced drag due to the reduction of wing-tip (in this case hulls) vortices while travelling at low altitudes near the water.
For sailing at least one ground effect wing, comprising: a fixed wing attached between forward end of the hulls and a second aero foil across the stern that has a negative dihedral angle with respect to the fixed wing is required to work.
The closer the ground effect wing is to the ground or water, the lower the drag due ground effect wings giving greater stability and lift. They cannot, however, sustain flight without maintaining close level distance to the surface.
no doubt that the larger plate on ETNZ if designed properly could create some lift… but keep in mind, that the boat weighs 13,000lbs plus crew and on its best point of sail might only have a windspeed of 50 mph coming across the deck moving upwind… and even less when going down wind.
small planes weight a lot less and barely take flight @ 50mph… with probably a similar square footage of wing
so while yes it may develop some lift…I think the benefit of it being an endplate to increase the wings efficiency and probably more importantly to increase the stiffness of the platform would be more likely
Who thought one narrow foil could lift 13,000lbs plus crew ? upwind, downwind & gybing ! thinking you’re under estimating the dynamics involved in these AC 72’s Marc…it’s new for everyone
The ETNZ aero package was only recently added (January) sure as hell an end plate that big would not for increased wing efficiency only, otherwise you would see commercial airliners using them to reduce fuel costs.!
Further there has never been a stiffness (structural) problem with ETNZ before they added the aerodynamic package and also the max race wind speed has since been dropped 30% … ETNZ designers are clever bunch is all I’m saying is there could be more to this than we are currently aware, than just old traditional sailing theory.
airplanes do…they call em winglets. F1 and Indy cars use them too. just keep in mind the fluid dynamics involved with lift. a fin though the water the water offers more resistance in this case lift. than the resulting air and gravity.
the endplate effect on ETNZ inpalce of the webbing really offers no extra wind resistance so the only penalty is weight. the benefits are the increase wing efficiency and potentially lift from ground effect.
I don’t discount that it may generate lift. even if it only generates enough lift to offset its added weight, the gains in wing efficiency are well worth it…
++++++++++++
After evaluating a range of winglet designs, Whitcomb published his findings in 1976, predicting that winglets employed on transport-size aircraft could diminish induced drag by approximately 20 percent and improve the overall aircraft lift-drag ratio by 6 to 9 percent.
Like other winglet designs, APB’s Blended Winglet reduces drag and takes advantage of the energy from wingtip vortices, actually generating additional forward thrust like a sailboat tacking upwind. Unlike other winglets that are shaped like a fold, this design merges with the wing in a smooth, upturned curve. This blended transition solves a key problem with more angular winglet designs, says Mike Stowell, APB’s executive vice president and chief technical officer.
“There is an aerodynamic phenomena called interference drag that occurs when two lifting surfaces intersect. It creates separation of the airflow, and this gradual blend is one way to take care of that problem,” he says.
the darned “replays” don’t include what happened that day. In fact, they are a full round-robin behind n the replays.
I will have to wait until NEXT WEEK to see what happed today with LR.
so much for the great media coverage…
it figured we get better coverage of the AC world series which did not mean diddley squat, and the events that really matter, nothing but delays…
This Vuitton Cup is really BOOOORING !!!
I suspect that will be the same in September a big FIASCO !!!
ClaudioD
Maybe the KIWI’s will straighten things out when they get the cup…
They can still get a big fleet of stars and go at it that way. They could probably round up a dozen in a day, let alone TWO WEEKS.
at least the fleet of ac45’s were exciting. and i would imagine got the crowds and TV ratings more than the crap they are broadcasting right now… Heck they could have been foiling on the ac45’s artemis was foiling easily…
After looking at the replays that are on YouTube, it looks like they only have ETNZ, and the only match(es) that were sailed.
IMO, either the TV network didn’t get any video of th ‘missing’ days, or the person uploading the videos didn’t want to show anything embarrassing or really boring, like 1 boat racing itself.