>I don't think there's sail shape or lift in the simulation..
No. It is a very rough simulation (I am not sure if I can even call that). It only takes into account the force of the wind 'hitting' on the sail and the 'drag reduction'.
I am not a physicist or have experience with sailing. I am just a freelance programmer (currently out of work) from India, which means I even haven't seen a real life sail boat. I made this using the stuff I got from Wikipedia and a bit of intuition. So I guess it shows.
But I have a question regarding the boat traveling faster than the wind. Isn't it due to the fact that the lift is a constant force, regardless of the speed at which the boat is traveling? But a boat that is using the force of wind hitting the sails, can only sail as fast as the wind, because at that point, there is no wind hitting the sails.
Hey, the script is cool. A more realistic simulation would probably very quite complex. You can still shape the boat a bit more like a sailboat to make it more intuitive (making it pointy just in the bow end = front).
As for the boat traveling faster than the wind, it has more to do with sailing angles than lift proper. The boat can get lift and push from "different air" as it slides perpendicularly with the direction of the wind. It's more of a constant force that produces acceleration until it's cancelled out by forces of resistance.
Typically the fastest points of sail of a boat (varies with hull shape, sails and their configuration) are about 45%-75% from the wind direction.
In polar diagrams 0% is into the wind, so 180% is dead downwind and 120% is about 60% away from dead downwind which is aprox the fastest direction for the boat described by that polar diagram.
Boats can travel faster than the wind because (ignoring surface resistance), they make their own 'wind' thanks to their speed. That wind combines with the true wind in generating the lift on sails even when the boat is travelling at wind speed or higher.
~~This can't happen if the boat is going straight downhill, because the apparent wind would be zero (as the boat is moving with the wind).~~
[ETA: that's not actually true in the general case. You can't have a sailboat move downwind faster than the wind, but if you have a gear mechanism and a turbine you can do it.]
But when tacking downhill, the movement of air around sails still generates lift.
No. It is a very rough simulation (I am not sure if I can even call that). It only takes into account the force of the wind 'hitting' on the sail and the 'drag reduction'.
I am not a physicist or have experience with sailing. I am just a freelance programmer (currently out of work) from India, which means I even haven't seen a real life sail boat. I made this using the stuff I got from Wikipedia and a bit of intuition. So I guess it shows.
But I have a question regarding the boat traveling faster than the wind. Isn't it due to the fact that the lift is a constant force, regardless of the speed at which the boat is traveling? But a boat that is using the force of wind hitting the sails, can only sail as fast as the wind, because at that point, there is no wind hitting the sails.