Why is it still possible for the boat to sail against the wind?
On the surface of the river, the wind was rushing; the sky was a color, the scene of boats going up and down, riding the wind and surfing, looked very majestic. At that time, do you pay attention to the scene: when the sailing boat comes, except for the fast downwind, the upwind can also run forward. We know that when a sailboat moves down the wind, it is based on the wind’s force on the sail, which propels the boat forward. But in the opposite conditions, why can boats sail as normal?
It was sailing while upwind is based on the dynamics of the wind acting on the boat. That requires the boatman to adjust the hull’s direction and the sail well, taking advantage of the general principle and skillfully analyzing the force for the wind to generate force.
Assuming a strong wind blows backward from the front, the boat driver advantageously adjusts the bow and sails to two different directions, B and P, to catch this reverse wind. The wind blows on the sail’s surface, the wind force W is analyzed into two component forces perpendicular to each other, namely P ‘and R,’ in which the component force P ‘blows up the surface of the sail, causing no effect on the boat. that R ‘component acts perpendicular to the sail. This main pressure R ‘can be further divided into two component forces A and B perpendicular to each other and A just exactly perpendicular to the hull. This force pushes the boat in a horizontal direction. Due to the horizontal direction, the resistance of the water to the boat is very large, so the force A pushes the boat sideways with the resistance of the water to the boat cancel each other out. Component force B of R ‘in the longitudinal direction of the boat. That is the force that makes the boat push. In combination with the foregoing, when the driver adjusts the ship and the sail to the necessary place, under the combined effect of the reverse wind and the drag, the sailboat is again motivated. However, the boat was coming at that time, because the bow tilted at an angle, it deviated from the direction. There is nothing to worry about. Waiting for the boat to run a distance, turning the bow and the sail towards the other side to catch the opposite wind, it is still possible to receive the momentum coming from the opposite wind. So we see the sails swirling around in an S-shaped shape and going in the opposite direction.
When sailing in the reverse wind, how to adjust the boat and sail to the best position to get the greatest motivation from the reverse wind? Experiments have shown that if the sail is adjusted to the equidistant line of the angle between the wind and the hull, the sail can get the greatest momentum. But it is not easy to do so. That must be entirely based on the driver’s many years of sailing experience. It is true: sailing against the wind, if not forward, backward.