Sailing upwind faster than downwind, or even faster than the wind, the principle is revealed

I saw on the news the other day that a sailing competition was being held in Haikou, Hainan, China. To be honest, I wasn't interested, but I was a bit surprised that there was such a competition. Boats are far away from my life, let alone sailing, and it sounds particularly retro. For most people, it should be. Because of various restrictions, boats can't be our daily means of transport, and even going by boat would be rare. Even people from coastal cities should see a little more than people from other places, but there are always fewer opportunities to ride

On the other hand, I feel helpless about the narrow scope of my life. The world is so big, people have their own lives, and what may seem like everyday things may be new experiences for others. People often get excited when they experience the everyday life of others. When they return to where they live, they continue to repeat the same old life. Although I couldn't try sailing myself, I was curious about how it worked.

When it comes to the principle of sailing, the first thought must be that it is powered by the wind and goes with the wind. This was indeed the case in ancient times when sailing ships were built with large canvases and masts that ran through the center of the ship to maximize the area and sail upwind. But nowadays most sailing ships do not rely entirely on the wind. There are now many triangular sailing boats with the sails standing up in the middle of the boat. Even against the wind, they can still go fast. What is it that makes sailing boats move? The answer is the Bernoulli effect.

As is customary, we begin with Bernoulli, the discoverer. Daniel Bernoulli was a Swiss mathematician and physicist, one of the most distinguished members of the Bernoulli family. His work involved algebra, calculus, grade theory, differential equations, probability theory, etc., but his best work was the application of calculus and differential equations to physics, studying fluid problems, vibrations, and oscillations of objects. He is considered to be the founder of the mathematical approach to physics and a pioneer in the fields of fluid mechanics, probability theory, and mathematical statistics.

Bernoulli effect, also known as the boundary layer surface effect. The Bernoulli effect applies to all ideal fluids, including liquids and gases, and is one of the fundamental phenomena in the steady flow of fluids. It reflects the relationship between fluid pressure and velocity, and the relationship between velocity and pressure: the higher the velocity of the fluid, the lower the pressure; the lower the velocity of the fluid, the higher the pressure.

The Bernoulli effect is still very widely used in reality. The sailboat we have just described is one of these. A gennaker is a curved sail. Although it is upwind, the Bernoulli effect occurs because the wind has to go around the bent sail. The wind speed is high and the air pressure low on the windward side, and low and strong on the leeward side. The boat is therefore heading under strong pressure. A little angle and conditions are also needed for the Bernoulli effect to occur, which is not possible especially when sailing downwind. When sailing with the Bernoulli effect, you also need to take a zigzag approach. Going against the wind from different angles produces the fastest forward speed.

In addition to the Bernoulli effect in sailing, there are other sports. Table tennis, for example. The topspin ball is an attack that is intense, short in distance, and has a large curve to the ball. The moment a table tennis ball is hit, it spins upwards, creating a circulation on the surface of the ball, which suffers from air resistance because it flies forward. The circulation at this point is the opposite of the air resistance above the ball and the same as the air resistance below the ball. The Bernoulli effect is also created and the ball has a downward force and acceleration. Our national table tennis players are masters of the Bernoulli effect and many of them win easily with topspin. The same is true of the banana ball in football.

Airplanes and birds both fly because of the Bernoulli effect. I don't know if you've noticed, but the bottom of a plane's wing is flat and the top is bulging out. This amplitude is the key to the Bernoulli effect. Even the fuselage of an aircraft, which is flat at the bottom and convex at the top, is not just for holding things in it. Without the Bernoulli effect, none of them would be able to soar through the sky. Think again, when the plane takes off, it doesn't take off vertically like a helicopter, but slowly through an assist. At this point, without the Bernoulli effect, the plane would not have been able to fly and would have had to move forward on land.

And the wings of birds are the same. Their wings are a bit curved. The bird's body keeps its abdomen flat during the flight. So the fluttering wings are just an aid to flight, it's the Bernoulli effect that allows them to soar. When they dive, why do they go faster? The same is true.

There are other everyday examples. Before we get on a train, high-speed train, or underground, we all have to wait on the platform to get on. Will there be a yellow line there? The reason for this range rule is that the vehicles are coming in with a Bernoulli effect, which attracts people to the car, which is very dangerous. So for your safety, make sure you don't get too close to the yellow line.

An effect that is widely used, we just don't know about it. Most people don't look deep enough into the story to explore how it works. When we understand a principle, we can see how many things work. It may not seem important, but when it comes to relevant issues, we can solve them as quickly as possible. That's a benefit we can't get in time.

My summary of the main points :

1. daniel Bernoulli was a Swiss mathematician and physicist, a member of the Bernoulli family, and one of the most distinguished. He is considered the founder of the mathematical-physical method and a pioneer in the fields of fluid mechanics, probability theory, and mathematical statistics.

2. The Bernoulli effect, also known as the boundary layer surface effect. The Bernoulli effect applies to all ideal fluids, including liquids and gases, and is one of the fundamental phenomena in the steady flow of fluids. It reflects the relationship between fluid pressure and velocity, the relationship between velocity and pressure: the higher the velocity of the fluid, the lower the pressure; the lower the velocity of the fluid, the higher the pressure.

The Bernoulli effect is used in many sports, such as sailing, the topspin of table tennis, and the banana ball of football.

4. The flight of aircraft and birds also make use of the Bernoulli effect.