帆是如何⼯作的……⼀点点科学! Because of the curve of the sail, air flowing round the outside of the sail moves faster than the air on the inside of the sail...
由于帆是呈曲线的,帆外侧的空⽓流动会⽐帆内侧要快……
This causes a pressure difference each side of the sail which sucks the sail to leeward. The force created is sideways on to the boom – so when close- hauled the whole boat is pushed sideways. This is where the centreboard or daggerboard comes in...