A few large cylinders erected on the ship can drive the ship forward. What kind of principle is hidden?
Such a ship with four large cylinders sailing on the sea is both weird and very interesting. Since the invention of the steam engine, ships have changed from sail power to steam power. The tall masts and sails were also replaced by chimneys, and now this weird ship is equipped with such a large cylinder, not for sailing, nor are there a few more large chimneys.
Instead, use the rotation of these large cylinders to provide power to the ship. This kind of ship with a rotating drum sail, also known as a Magnus rotor ship, is generally used in ships that want to save energy and increase speed. On the freighter, because the freighter does not care about the appearance and shape, even if there is such a weird drum, it has no effect, and it can be used to save power.
Although this kind of ship is not widely used in practical applications at present, it is definitely not a new product, but has existed for a long time. As early as 1926, there was a freighter called Bukaw, which was equipped with two such large cylinders. , to cross the Atlantic by turning it on the wind to power it. However, the modern-made cargo ship with a large drum does not completely use the drum to provide power. Instead, after the turbine is driven by the steam, the residual airflow drives the rotating drum, and uses the principle of aerodynamics to play a role in boosting.
But the basic principle of using a large cylindrical drum to provide power is not problematic at all, and it is also called the Magnus effect. It is also very simple to verify this principle, and there are many similar experiments. For example, one of the experiments is like this. On a guide rail that can slide back and forth, a slider is installed, and a cylindrical rotating drum similar to a ship is installed above the slider.
As the drum rotates under battery power, an electric fan runs on its side. The drum rotates counterclockwise, and when the electric fan blows air on the left side, a magical scene appears, and the slider is driven to move backward. While the fan remains unchanged, it just changes the direction of rotation, and when turning clockwise, the slide block moves forward rapidly again.
It seems that the large cylinders on the ship do have a reason to exist, and the Magnus effect is used, and not only cylinders, but also spheres have such characteristics, so there are also such characteristics in ball games. Applications of the Magnus Effect.
The rotation of several large cylinders can drive the ship forward, which is the Magnus effect. What is the principle of such an incredible effect?
The large cylinder on the Magnus rotor ship can propel the ship forward by rotating and using air power. It sounds amazing, and this magic does not come from human beings, but mainly from the mysterious power of nature. And after uncovering the mysteries, you will surely marvel at the magic of nature. Our common ball rotation also has such a Magnus effect. Let us try to explain this principle with the rotation of a ball.
When shooting in football, there are often experts who kick banana balls with arcs. This arc does not refer to a parabola in the vertical direction. Rather, it refers to the curvature in the horizontal direction. Usually, players who kick the ball with their right foot will deflect the trajectory of the banana ball to the left, creating the illusion of surprise for the goalkeeper.
The reason why the football suddenly deflects to the left in the air is that when the player is kicking the ball, he is kicking the right side of the ball. While giving the football a forward force, it also has an additional force to turn to the left. So while the football is flying forward, it is also spinning counterclockwise to the left. At the same time, the high-speed rotation of the football drives the airflow around the ball to rotate counterclockwise.
On the left side of the forward direction of the football, the oncoming airflow and the airflow driven by the football are in the same direction, and the speed of the air flow will be accelerated. According to the principle of aerodynamics, the faster the airflow, the lower the atmospheric pressure, and the airflow on the right side of the football collides with the oncoming airflow, making the airflow slower and the pressure higher. In this way, the pressure difference formed on the left and right sides gives the football a force to the left, thus forming a magical banana ball effect.
If the player is kicking the ball with his left foot, an opposite arc will be formed. In addition to football, table tennis, tennis and other high-speed flying balls will have such a Magnus effect. The spin balls played by Chinese table tennis players also use this effect. Then, after understanding the application of the Magnus effect on the sphere, it is the same reason to change the sphere into a rotating cylinder, and it can also play a role in auxiliary propulsion when applied to a ship.
Can the Magnus effect that allows the rotating drum to assist the ship to drive, in addition to being used on freighters, can it also be applied to aircraft?
In order to verify whether the cylindrical drum conforms to the Magnus effect in the vertical direction, we can do such a small experiment. Tie the two sides of a paper tube with a thin wire to hang it, and then rotate it clockwise upwards, so that when the paper tube falls freely when you let go, it will fall counterclockwise, and the air flow on the left will be faster and the pressure will be lower , and is pushed to the left by a leftward force. Then similarly, if it is changed to rotate counterclockwise, it will deflect to the right after free fall, which shows that the Magnus effect is also applicable in the vertical direction.
Therefore, some aviation researchers have produced a model of a rotary aircraft, using the cylinder that is constantly rotating backwards on the aircraft to drive the airflow to rotate, so the airflow above the rotary cylinder has a faster flow rate and a lower pressure. The airflow below is slower and the pressure is higher, and the pressure difference between the upper and lower sides forms an upward lift, which pushes the aircraft up. This method uses the same aerodynamic principle as ordinary fixed-wing aircraft.
However, the rotor of this kind of aircraft is not only the source of power to generate lift, but also an important part to maintain lift. Once it is damaged and stops rotating, the aircraft will have no chance to taxi and land. Therefore, it is still possible to make a model aircraft, but it will be very dangerous if it is applied to an actual aircraft, so there is no actual aircraft using this method at present.
However, the ship uses the cylindrical rotor made of the Magnus principle, and auxiliary propulsion is still completely achievable. So what should the ship do if the ship uses the rotating drum to deflect it? In fact, what the Magnus rotorship uses is not the vertical wind direction in the forward direction of the ship, but the transverse wind from both sides of the ship. Generally, the speed of ships sailing on the sea is relatively slow. If the transverse sea wind is very strong, the course of the ship will be blown off. Not only does it need to constantly correct the course, but it will also consume the power of the ship.
But the advantage of the rotor boat is that it converts such cross wind into forward thrust. If the wind comes from the left, it will rotate clockwise, and if the wind comes from the right, it will rotate counterclockwise. It is really a very ingenious design, but because the large rotating drum affects the appearance after all, only ocean freighters have such a design.