Watched a very techie video today about the wing design. Basically, it was suggesting that before Christmas Ineos appeared to have gone the wrong way with their wings. But now it looks like they’ve gained an advantage.
Ineos has delta shaped wings; they look like a Vulcan bomber. All of the other boats of long, narrow wings like a glider.
Hydrodynamics suggest that the delta wing is the wrong way to go; they only well work at high speeds. At low speeds they are unstable and very difficult to control (think Typhoon winglets, computer controlled). So Ineos couldn’t get up onto her foils in the Christmas Cup because their control systems weren’t working properly. To make matters worse, the wings were taking in water; watch videos of them sailing before Christmas and water streams out of the wings as they are raised.
The up side of delta wings is that they have a bigger internal volume, so bigger hydraulic rams for the tabs are operating direct (the rams are fitted fore to aft). On the long thin wings, the smaller rams are at 90 degrees to the hull and drive through a gear.
Delta wings also give more lift at high speeds. They suggested that at speeds of 45kts and above, Ineos will have a distinct advantage.
The core conclusion amongst lots of boring conversation about Reynolds Numbers is that Ineos may have stolen a march. They’ve solved the water ingress issue and have developed software to control the tabs that works quicker than a human can. The suggested differentiator is Mercedes at Brackley.
I’ll post the video if I can find it again! Meantime, check out the wing shapes.