7 ms·
If the relative wind is mostly coming at you from the direction you're traveling, then the component of the relative wind in the direction of the ship is negati
by jrpt 4y ago
If the relative wind is mostly coming at you from the direction you're traveling, then the component of the relative wind in the direction of the ship is negative. So I'm having trouble figuring out how this actually works to convert that into a force going in the ship's direction. Do you have a quick primer for how the physics of it works? Like a small explainer of this claim: "standard sails can still produce forward thrust as long as the wind is at least 20 degrees off from directly in front of the vessel"
- Schroedingersat 4y agoIt's the same way racing yachts can move significantly faster than the wind. Think of it from the boats point of view. If the wind has a mass of 1 unit and is moving at 1unit/s 20 degrees from headwind in the boat's frame, then it has an x component of 0.34 units/s and a y component of 0.93 units/s. Redirecting it purely in the y direction moves it at 1 unit/s giving a momentum to the boat of 0.07 units. The 0.34 units in the x direction gets resisted by the water. The theoretical perfect boat with perfect sails and no slip and no drag will always accelerate in its own frame as long as there is some cross wind (at an ever decreasing rate) as it is always accelerating air backwards by removing the x component and keeping energy constant.
- arwineap 4y agoAre these even meant to go upwind? There's no keel, and I didn't see anything about a daggerboard in the design
- Schroedingersat 4y agoNot directly upwind. Sails can't do that without tacking. But any airfoil will point beyond a reach. A ship has some lateral resistance even without having a separate part you specifically call a keel. The exact angle doesn't seem to be stated.