Their claim about the wing being twice as effective is just a claim and is wrong. They need to be out and racing if they want to prove that point. Sail against boats of similar displacement and configuration with soft sails of twice the area. See which one completes a course first.
There is a really interesting couple of frames in the video at 3:39 where the boat rides over a wave and the wing starts a rhythmic roll. It then cuts. Can you imagine what that wing would be like with 6 to 7 tones oscillating wildly aloft in 35kts of wind and combined with 3m waves. No place to hide and no means of getting rid of all that violently swinging mass up high.
I have taken a series of successive images below to show how violently the wing has swung about as the boat has rolled. Imagine how much the force on the wing varies with an angular change like that.
The boat yaws quite badly underneath the wing on the waves as well because it does not produce a stabilising moment like sails sheeted to a hull. That is a problem similar to what we have encountered with the Aerorig during a shunt as sheeting on the boom quickly pulls the boat up into the wind due to the moment it can produce.
On 09/01/2016, at 8:30 PM, robriley@rocketmail.com [harryproa] <harryproa@yahoogroups.com.au> wrote:
45ft tall 10ft chord and weighs 600lbs
produces 6-7 tonnes of force
and they claim on an equal size soft sail and wing, the wing is going to be twice as effective
__._,_.___
Posted by: Rick Willoughby <rickwill@bigpond.net.au>
| Reply via web post | • | Reply to sender | • | Reply to group | • | Start a new topic | • | Messages in this topic (72) |
.