Experimental Apparatus and Methods for Investigating the Magnus Effect

Abstract

An experimental apparatus and method for investigating the Magnus effect are disclosed. The base includes a launching mechanism, an air compression mechanism, and an air volume adjustment mechanism. The launching mechanism includes an angle indicator disk with a launching angle adjustment mechanism at its bottom. A launching tube is connected to the center of the angle indicator disk via a power air intake pipe. A suspension seat connected to the wall of the launching tube is located inside the launching tube above the power air intake pipe. An air guide pipe is located at the center of the suspension seat, and the upper end of the power air intake pipe is inserted into the air guide pipe. The launching object is placed on the suspension seat. A suspension air intake pipe is located on the lower side wall of the power air intake pipe. A left-handed and a right-handed air intake pipe, symmetrical about the centerline, are located in the middle of the side wall of the launching tube. A reflective photoelectric speed sensor is installed on the side wall of the launching tube below the right-handed air intake pipe. The air compressor is connected to the left-handed and right-handed air intake pipes, the power air intake pipe, and the suspension air intake pipe via the air volume adjustment mechanism. This invention clearly and intuitively demonstrates the principle of the influence of the Magnus effect on the flight trajectory of the launching object.

Description

Technical Field

[0001] This invention belongs to the field of fluid mechanics teaching instrument technology, specifically relating to experimental apparatus and methods for exploring the Magnus effect. Background Technology

[0002] The Magnus effect is an important phenomenon in fluid mechanics, representing Bernoulli's principle in more complex flow fields. It is primarily manifested as follows: when the angular velocity vector of a rotating object does not coincide with its velocity vector, a lateral force is generated in a direction perpendicular to the plane formed by the angular velocity and translational velocity vectors. The phenomenon of the object's trajectory being deflected under the influence of this lateral force is called the Magnus effect. The Magnus effect has been widely applied and researched in shipbuilding, aviation, and wind power generation, such as in rotary sails, rudders, roll reduction devices, wind turbine optimization, aircraft design, and rotating projectiles. While the Magnus effect is a crucial concept in fluid mechanics, its abstract theory presents some challenges for students. Therefore, developing experimental teaching instruments that can intuitively and effectively demonstrate the Magnus effect is essential.

[0003] The "spin ball" or "banana ball" is considered a visual representation of the Magnus effect and is the most typical example used in physics courses to explain it to students. However, not every student has the opportunity to witness the "spin ball" or "banana ball" firsthand. Although there are several patent applications for simulation or training devices for launching "spin balls," they are all sports equipment and cannot be used as teaching instruments for students to explore the influence of the ball's rotation direction, rotation speed, and angular velocity vector (the spatial direction of the rotation axis) on the ball's trajectory, landing point, and distance. Currently, there are also many patents for demonstrating the Magnus effect, such as Chinese invention patent (ZL201410480266.0) "Magnus Effect Demonstration Instrument" and Chinese invention patent (ZL201410501876.4) "A Magnus Effect Demonstration Instrument," which provide a Magnus effect demonstration instrument for popular science demonstrations. Its characteristic is that it uses a fan as the airflow source, and demonstrates the change in the direction of the lateral force on a rotating cylinder due to the Magnus effect by changing the rotation direction of the cylinder in the airflow field. However, the explanation of the principles of "spinning sphere" and "banana ball" is not intuitive. Furthermore, it is difficult to generate high-speed airflow in semi-open or open environments using ordinary fans as the airflow source, which affects the demonstration effect. In particular, the rotational angular velocity vector (spatial direction) of the rotating cylinder can only be changed by the rotation direction of the cylinder, and there are only two directions. This cannot meet the experimental needs of students to explore the relationship between the rotational angular velocity vector (spatial direction) of an object and its flight trajectory by independently changing the spatial direction of the rotational angular velocity vector. Summary of the Invention

[0004] This invention addresses the shortcomings of existing technologies in enabling students to conduct experimental investigations into the Magnus effect. It provides an experimental apparatus and method for intuitively demonstrating and investigating the influence of changes in the launch angle, rotational speed, rotational direction, and rotational angular velocity vector (spatial direction) of a launcher on the launcher's flight trajectory and landing point.

[0005] The technical solution adopted to solve the above-mentioned technical problems is: a Magnus effect investigation experimental device, wherein a base is provided with a launching mechanism, an air compression mechanism, and an air volume adjustment mechanism. The launching mechanism includes an angle indicator disk, and a launching angle adjustment mechanism is provided at the bottom of the angle indicator disk. A transparent launching tube is rotatably connected to the center of the angle indicator disk through a power air intake pipe. The center line of the launching tube coincides with the axis of the angle indicator disk. The power air intake pipe is installed through the center of the bottom of the launching tube and the center of the angle indicator disk. A suspension seat connected to the wall of the launching tube is provided inside the launching tube above the power air intake pipe. An air guide pipe is provided at the center of the suspension seat, and the upper end of the power air intake pipe is inserted into the air guide pipe. The launcher is placed on the suspension seat, and there is a gap between the launcher and the side wall of the launch tube. A suspension air intake pipe is set on the lower side wall of the power air intake pipe. A left-handed air intake pipe and a right-handed air intake pipe are symmetrical about the center line in the middle of the side wall of the launch tube. A reflective photoelectric speed sensor is set on the side wall of the launch tube below the right-handed air intake pipe. A strip-shaped reflective film is set on the launcher to provide reflected light signals to the reflective photoelectric speed sensor. The air compression mechanism includes an air compressor and a pressure reducing valve connected to the output end of the air compressor. The air compression mechanism is connected to the left-handed air intake pipe, the right-handed air intake pipe, the power air intake pipe, and the suspension air intake pipe through an air volume regulating mechanism.

[0006] As a preferred technical solution, the launcher is a spherical launcher and the suspension seat is a spherical crown shape.

[0007] As a preferred technical solution, the emitter is a cylindrical emitter, and the suspension seat is an arc-shaped plate.

[0008] As a preferred technical solution, the intersection of the center lines of the left-hand and right-hand air inlet pipes with the center line of the launch tube is located below the center of the spherical launcher or the central axis of the cylindrical launcher when the launcher is stationary, and the distance between the intersection and the center of the spherical launcher or the central axis of the cylindrical launcher is h = 2 / 3R, where R is the radius of the launcher.

[0009] As a preferred technical solution, the angle between the centerline of the left-hand and right-hand air intake pipe and the centerline of the launch tube is α, where 20°≤α≤50°. The inner diameter of the left-hand or right-hand air intake pipe is 1 / 4 times the inner diameter of the power air intake pipe, and the inner diameter of the suspended air intake pipe is 1 / 8 times the inner diameter of the power air intake pipe.

[0010] As a preferred technical solution, the emission angle adjustment mechanism includes a left support column and a right support column, which are hinged to the left and right sides of the bottom of the angle indicator disk. The left support column is a fixed rod, and the right support column is a telescopic rod.

[0011] As a preferred technical solution, the air volume regulating mechanism includes an air distribution pipe, a left-hand solenoid valve, a right-hand solenoid valve, a power solenoid valve, and an adjustable solenoid valve. The air distribution pipe is provided with an air inlet pipe and four parallel air outlet pipes. The air inlet pipe of the air distribution pipe is connected to the air compression mechanism through a pipeline. The left-hand solenoid valve, the right-hand solenoid valve, the power solenoid valve, and the adjustable solenoid valve are respectively installed on the four air outlet pipes and are connected to the left-hand air inlet pipe, the right-hand air inlet pipe, the power air inlet pipe, and the suspended air inlet pipe through pipelines.

[0012] This invention also provides an experimental method for an experimental apparatus for investigating the Magnus effect, comprising the following steps:

[0013] S1. Observation of the launcher's flight trajectory when the launcher is not rotating.

[0014] S1.1. Open the power solenoid valve, right-hand solenoid valve, and left-hand solenoid valve to start the air compressor mechanism, adjust the output pressure of the air compressor mechanism to the predetermined value, and then close the power solenoid valve, right-hand solenoid valve, and left-hand solenoid valve.

[0015] S1.2. The launcher is loaded into the launch tube from the top opening;

[0016] S1.3. Rotate the launch tube so that the right-hand air intake pipe is exactly at the 0° mark on the angle indicator disc. Then adjust the angle between the angle indicator disc and the horizontal plane so that the launch angle of the launcher is 70° to 80°.

[0017] S1.4. Open the power solenoid valve. The powerful airflow from the power intake pipe acts on the launcher, and the launcher quickly launches the launch tube. Observe the flight trajectory of the launcher and mark the landing point. At the same time, close the power solenoid valve.

[0018] S2. Observation on the effect of the launcher's rotational speed on its flight trajectory

[0019] S2.1. Insert the emitter into the emitter tube, so that the strip of reflective film attached to the emitter is in the horizontal direction and the middle part of the strip of reflective film along its length is aligned with the reflective photoelectric speed sensor installed on the emitter tube.

[0020] S2.2. Rotate the launch tube so that the right-hand air intake pipe is exactly at the 0° mark on the angle indicator disc. Then adjust the angle between the angle indicator disc and the horizontal plane so that the launch angle of the launcher is 70° to 80°.

[0021] S2.3. Adjust the adjustable solenoid valve to slowly increase the air intake in the suspension air intake pipe, while observing the launcher located on the suspension seat. When the launcher just floats up on the suspension seat, stop adjusting the adjustable solenoid valve.

[0022] S2.4. Turn on the reflective photoelectric speed sensor and open the right-hand solenoid valve. The right-hand air intake pipe sprays out airflow, which acts on the launcher. Observe from the right side of the launch tube. The launcher rotates clockwise. At the same time, observe the reflective photoelectric speed sensor. When the speed of the launcher reaches n1 rpm, 400≤n1≤600, open the power solenoid valve. The powerful airflow sprayed from the power air intake pipe acts on the launcher. The launcher rotates and is launched out of the launch tube quickly. Observe the flight trajectory of the launcher and mark the landing point. At the same time, close the power solenoid valve and the right-hand solenoid valve. Put the launcher into the launch tube and make the strip of reflective film attached to the launcher horizontal and the middle part of the length of the strip of reflective film aligned with the reflective photoelectric speed sensor installed on the launch tube.

[0023] S2.5. Open the right-hand solenoid valve, and the right-hand intake pipe will eject airflow. The airflow acts on the launcher. Observing from the right side of the launch tube, the launcher rotates clockwise on the suspension seat. At the same time, the reflective photoelectric speed sensor measures the speed of the launcher. When the speed of the launcher reaches n2 rpm, n2 > n1. Open the power solenoid valve, and the powerful airflow ejected from the power intake pipe acts on the launcher. The launcher rotates and is launched out of the launch tube quickly. Observe the flight trajectory of the ball and mark the landing point. At the same time, close the power solenoid valve, the right-hand solenoid valve, and the adjustable solenoid valve.

[0024] S2.6. Compare the flight trajectory and landing point of the launcher observed in steps S1.4, S2.4, and S2.5, analyze the principle of the influence of whether the launcher rotates and the magnitude of the launcher's rotation speed on the flight trajectory and landing point, and understand the role of the Magnus effect.

[0025] S3. Observation of the influence of launcher rotation direction on flight trajectory

[0026] S3.1. Prepare according to steps S2.1 to S2.3, open the left-hand solenoid valve, the left-hand air intake pipe sprays out airflow, the airflow acts on the launcher, observe from the right side of the launch tube, the launcher rotates counterclockwise on the suspension seat, at the same time observe the reflective photoelectric speed sensor, when the rotation speed of the ball reaches n2 rpm, open the power solenoid valve, the powerful airflow sprayed from the power air intake pipe acts on the launcher, the launcher rotates and is launched out of the launch tube quickly, observe the flight trajectory of the launcher and mark the landing point, at the same time close the power solenoid valve, the right-hand solenoid valve, the adjustable solenoid valve and the reflective photoelectric speed sensor;

[0027] S3.2. Compare the flight trajectory and landing point of the launcher observed in experimental steps S1.4, S2.5, and S3.1, analyze the principle of the influence of whether the launcher rotates and the direction of rotation on the flight trajectory and landing point, and understand the role of the Magnus effect.

[0028] S4. Observation of the influence of the launcher's rotational angular velocity vector on the launcher's flight trajectory

[0029] S4.1. Insert the emitter into the emitter tube, so that the strip of reflective film attached to the emitter is in the horizontal direction and the middle part of the strip of reflective film along its length is aligned with the reflective photoelectric speed sensor installed on the emitter tube.

[0030] S4.2. Rotate the launch tube so that the right-hand rotating air inlet pipe is exactly at the 90° mark on the angle indicator disc. Then adjust the angle between the angle indicator disc and the horizontal plane so that the launch angle of the launcher is 70° to 80°.

[0031] S4.3. Adjust the adjustable solenoid valve to slowly increase the air intake in the suspension air intake pipe, while observing the launcher located on the suspension seat. When the launcher just floats on the suspension seat, stop adjusting the adjustable solenoid valve.

[0032] S4.4. Turn on the reflective photoelectric speed sensor and open the right-hand solenoid valve. The airflow from the right-hand intake pipe acts on the launcher. Observing from the front of the launch tube, the launcher rotates clockwise on the suspension seat. That is, the angular velocity vector of the launcher points to the 0° or 360° scale line on the angle indicator disk. Observe the reflective photoelectric speed sensor. When the speed of the launcher reaches n2 rpm, open the power solenoid valve. The powerful airflow from the power intake pipe acts on the launcher. The launcher rotates and is launched out of the launch tube quickly. Observe the flight trajectory of the launcher and mark the landing point. At the same time, close the power solenoid valve and the right-hand solenoid valve. Put the launcher into the launch tube and make the strip of reflective film attached to the launcher horizontal and the middle part of the length of the strip of reflective film aligned with the reflective photoelectric speed sensor installed on the launch tube.

[0033] S4.5. Rotate the launch tube so that the right-hand intake pipe is positioned at the α angle scale line on the angle indicator disk, 0° < α < 90°; open the right-hand solenoid valve, and the airflow from the right-hand intake pipe acts on the launcher. Observing from the right front of the launch tube, the launcher rotates clockwise on the suspension seat, that is, the rotational angular velocity vector of the launcher points to the 270° + α scale line on the angle indicator disk; observe the reflective photoelectric speed sensor. When the launcher's rotational speed reaches n2 rpm, open the power solenoid valve. The powerful airflow from the power intake pipe acts on the launcher, and the launcher rotates and is quickly launched out of the launch tube. Observe the launcher's flight trajectory and mark the landing point. At the same time, close the power solenoid valve and the right-hand solenoid valve, and put the launcher into the launch tube, so that the strip of reflective film attached to the launcher is in the horizontal direction and the middle part of the strip of reflective film along its length is aligned with the reflective photoelectric speed sensor installed on the launch tube.

[0034] S4.6. Rotate the launch tube so that the right-hand intake pipe is positioned at the β angle scale line on the angle indicator disk, 90° < β < 180°; open the right-hand solenoid valve, and the airflow from the right-hand intake pipe acts on the launcher. Observing from the left front of the launch tube, the launcher rotates clockwise on the suspension seat, that is, the rotational angular velocity vector of the launcher points to the β-90° scale line on the angle indicator disk; observe the reflective photoelectric speed sensor. When the launcher's rotational speed reaches n2 rpm, open the power solenoid valve. The powerful airflow from the power intake pipe acts on the launcher, and the launcher rotates and is quickly launched out of the launch tube. Observe the trajectory of the sphere and mark the landing point. At the same time, close the power solenoid valve, the right-hand solenoid valve, the adjustable solenoid valve, the reflective photoelectric speed sensor, the air compression mechanism, and reinstall the launcher back into the launch tube.

[0035] S4.7. Compare the flight trajectory and landing point of the launcher observed in experimental steps S4.4, S4.5, and S4.6, analyze the principle of the influence of the launcher's rotational angular velocity vector on the launcher's flight trajectory and landing point, and understand the role of the Magnus effect.

[0036] The beneficial effects of this invention are as follows:

[0037] This invention uses compressed air as the power source for the rotation and launch of the launcher. The launch angle, rotation direction, rotation speed, and angular velocity vector (i.e., the direction of the rotation axis in space) of the launcher are all adjustable. Experiments were conducted to investigate the influence of the launch angle, rotation direction, rotation speed, and angular velocity vector on the launcher's flight trajectory, landing point's orientation, and distance. The invention clearly and intuitively demonstrates the principle of the Magnus effect on the launcher's flight trajectory.

[0038] Compared to existing technologies, this invention avoids the use of complex mechanical rotation or launching mechanisms. It features a simple and transparent structure, rich experimental content, significant experimental results, low cost, easy and convenient operation, and virtually no maintenance required. It can not only meet the experimental needs of students to explore the Magnus effect in depth, but also be used for popular science demonstrations for the general public. Attached Figure Description

[0039] Figure 1 This is a schematic diagram of the experimental apparatus for investigating the Magnus effect of this invention.

[0040] Figure 2 This is a top view of Embodiment 1 of the present invention.

[0041] Figure 3 This is a schematic diagram of the launching mechanism of the present invention.

[0042] Figure 4 This is a top view of Embodiment 2 of the present invention.

[0043] The components include: base 1, left support column 2, suspension air intake pipe 3, right support column 4, air compression mechanism 5, air distribution pipe 6, angle indicator 7, retaining ring 8, power air intake pipe 9, air guide pipe 10, reflective photoelectric speed sensor 11, right-handed air intake pipe 12, launch tube 13, left-handed air intake pipe 14, spherical launcher 15, suspension seat 16, right-handed solenoid valve 17, power solenoid valve 18, adjustable solenoid valve 19, left-handed solenoid valve 20, and cylindrical launcher 21. Detailed Implementation

[0044] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments, but the present invention is not limited to the following embodiments.

[0045] Example 1

[0046] exist Figure 1 , 2 In 3, the experimental apparatus for investigating the Magnus effect in this embodiment is a base 1 equipped with a launching mechanism, an air compressor 5, and an air volume regulating mechanism. The air compression mechanism 5 consists of an air compressor and a pressure reducing valve connected to the output end of the air compressor. The air compression mechanism 5 compresses air and provides power to the launching mechanism through the air volume regulating mechanism.

[0047] The launching mechanism includes an angle indicator dial 7, a launch angle adjustment mechanism, a launch tube 13, a power air intake pipe 9, a suspension air intake pipe 3, a suspension base 16, a spherical launcher 15, a retaining ring 8, a left-hand spiral air intake pipe 14, a right-hand spiral air intake pipe 12, and a reflective photoelectric speed sensor 11. The upper surface of the angle indicator dial 7 is engraved with angle scale lines from 0° to 360°. The launch angle adjustment mechanism is installed at the bottom of the angle indicator dial 7 to adjust the angle between the angle indicator dial 7 and the horizontal plane. The launch tube 13 is connected to the angle indicator dial 7 via the power air intake pipe 9.

[0048] Launch tube 13 is a transparent cylindrical shape, coaxial with angle indicator 7. Power intake pipe 9 is installed through the center of the bottom of launch tube 13 and the center of angle indicator 7, and is fixed vertically by retaining ring 8. Launch tube 13 can rotate on angle indicator 7 around power intake pipe 9. Above power intake pipe 9, inside launch tube 13, is a suspension seat 16 connected to the wall of launch tube 13. Suspension seat 16 is a spherical crown shape matching the shape of the spherical launcher 15. Air guide pipe 10 is located at the center of suspension seat 16. The upper end of the 9 is inserted into the air guide tube 10. A spherical emitter 15 is placed on the suspension seat 16. The spherical emitter 15 is a size 2 (15cm in diameter) soccer ball. A strip of reflective film with a width of 0.5-1cm and a length of 1 / 2 the circumference of the sphere is attached to the surface of the soccer ball. The strip of reflective film is used to provide reflected light signals to the reflective photoelectric speed sensor 11. There is a gap between the spherical emitter 15 and the side wall of the launch tube 13. The gap width is 3-5mm to ensure that the spherical emitter 15 is in close contact with the launch tube 13 during rotation and launch. A thin layer of airflow exists between the inner walls of the launch tube 13 to prevent the friction between the spherical launcher 15 and the inner wall of the launch tube 13 from affecting the movement of the spherical launcher 15, while also ensuring that the spherical launcher 15 obtains sufficient launch power. A left-handed air inlet pipe 14 and a right-handed air inlet pipe 12 are symmetrically installed about the axis in the middle of the side wall of the launch tube 13. The angle between the centerline of the left-handed air inlet pipe 14 and the axis of the launch tube 13 is α, where α = 30°, or it can be 20° or 50°. The centerlines of the left-handed air inlet pipe 14 and the right-handed air inlet pipe 12 are... The intersection of the line and the axis of the launch tube 13 is located below the center of the spherical launcher 15 when it is stationary, and the distance between the line and the center is h = 2 / 3R, where R is the radius of the spherical launcher 15. The inner diameter d of the left-hand intake pipe 14 or the right-hand intake pipe 12 is 1 / 4 times the inner diameter D of the power intake pipe 9. A reflective photoelectric speed sensor 11 is installed on the side wall of the launch tube 13 below the right-hand intake pipe 12. A suspended intake pipe 3 is installed on the lower side wall of the power intake pipe 9, and the inner diameter of the suspended intake pipe 3 is 1 / 8 times the inner diameter of the power intake pipe 9. The air compressor 5 is connected to the left-hand intake pipe 14, the right-hand intake pipe 12, the power intake pipe 9, and the suspended intake pipe 3 through an air volume regulating mechanism.

[0049] The emission angle adjustment mechanism of this embodiment includes two left pillars 2 and two right pillars 4. The two left pillars 2 and two right pillars 4 are rectangularly distributed and supported at the bottom of the angle indicator disk 7. The left pillar 2 is a fixed rod with its upper end hinged to the bottom of the angle indicator disk 7 and its lower end fixedly installed on the base 1. The right pillar 4 is a telescopic rod with its upper end hinged to the bottom of the angle indicator disk 7 and its lower end fixedly installed on the base 1. The angle between the angle indicator disk 7 and the horizontal plane can be adjusted by adjusting the height of the right pillar 4.

[0050] The air volume regulating mechanism of this embodiment includes an air distribution pipe 6, a left-hand solenoid valve 20, a right-hand solenoid valve 17, a power solenoid valve 18, and an adjustable solenoid valve 19. The air distribution pipe 6 is provided with an air inlet pipe and four parallel air outlet pipes. The air inlet pipe of the air distribution pipe 6 is connected to the air compression mechanism 5 through a pipe. The left-hand solenoid valve 20, the right-hand solenoid valve 17, the power solenoid valve 18, and the adjustable solenoid valve 19 are respectively installed on the four air outlet pipes of the air distribution pipe 6 and are connected to the left-hand air inlet pipe 14, the right-hand air inlet pipe 12, the power air inlet pipe 9, and the suspended air inlet pipe 3 through pipes. When the power solenoid valve 18 is opened, a strong airflow is ejected from the power intake pipe 9 to provide the launching power for the spherical launcher 15. When the adjustable solenoid valve 19 is opened, airflow enters the power intake pipe 9 from the suspension intake pipe 3 and is ejected from the air guide pipe 10 at the center of the suspension seat 16, forming a thin airflow layer between the spherical launcher 15 and the suspension seat 16, causing the spherical launcher 15 to suspend above the suspension seat 16. When the spherical launcher 15 is in a suspended state, the left-hand solenoid valve 20 is opened, and airflow enters from the left-hand intake pipe. When the airflow from pipe 14 acts on the spherical launcher 15 and flows rapidly through the air gap between the spherical launcher 15 and the suspension seat 16, it causes the spherical launcher 15 to rotate above the suspension seat 16. When the spherical launcher 15 is in a suspended state, the right-hand solenoid valve 17 is opened, and the airflow is ejected from the right-hand air intake pipe 12. When the airflow acts on the spherical launcher 15 and flows rapidly through the air gap between the spherical launcher 15 and the suspension seat 16, it causes the spherical launcher 15 to rotate above the suspension seat 16.

[0051] The experimental method of the Magnus effect investigation apparatus in this embodiment includes the following steps:

[0052] S1. Observation of the flight trajectory of the spherical launcher 15 when it is not rotating.

[0053] S1.1. Open the power solenoid valve 18, the right-hand solenoid valve 17, and the left-hand solenoid valve 20 to start the air compressor mechanism 5. Adjust the pressure reducing valve to make the output pressure of the air compressor mechanism 0.5MPa, and then close the power solenoid valve 18, the right-hand solenoid valve 17, and the left-hand solenoid valve 20.

[0054] S1.2. Insert the spherical launcher 15 into the launch tube 13 from the top opening;

[0055] S1.3. Rotate the launch tube 13 so that the right-rotating air inlet pipe 10 is exactly at the 0° mark on the angle indicator disk. Then adjust the angle between the angle indicator disk 7 and the horizontal plane so that the launch angle of the spherical launcher 15, i.e. the angle between the center line of the launch tube 13 and the horizontal plane, is 80° to 70°. In this embodiment, the launch angle of the experimental ball 13 is 75°.

[0056] S1.4. Open the power solenoid valve 18. The powerful airflow ejected from the power intake pipe 9 acts on the spherical launcher 15. The spherical launcher 15 quickly launches the launch tube 13. Observe the flight trajectory of the spherical launcher 15 and mark the landing point. At the same time, close the power solenoid valve 18.

[0057] S2. Observation on the effect of the rotational speed of the spherical launcher 15 on the trajectory of the sphere.

[0058] S2.1. Insert the spherical emitter 15 into the emitter tube 13, so that the strip-shaped reflective film attached to the spherical emitter 15 is in the horizontal direction and the middle part of the strip-shaped reflective film in the length direction is aligned with the reflective photoelectric speed sensor 11 installed on the emitter tube 13.

[0059] S2.2. Rotate the launch tube 13 so that the right-hand air intake pipe 12 is exactly at the 0° or 360° mark on the angle indicator disk; then adjust the angle between the angle indicator disk 7 and the horizontal plane so that the launch angle of the spherical launcher 15 is 75°.

[0060] S2.3. Adjust the adjustable solenoid valve 19 to slowly increase the air intake in the suspension air intake pipe 3, while observing the spherical emitter 15 located on the suspension seat 16. When the spherical emitter 15 just floats on the suspension seat 16, stop adjusting the adjustable solenoid valve 19.

[0061] S2.4. Turn on the reflective photoelectric speed sensor 11, open the right-hand solenoid valve 17, and the right-hand air intake pipe 12 sprays out airflow. The airflow acts on the spherical emitter 15. Observe from the right side of the launch tube 13. The spherical emitter 15 rotates clockwise on the suspension seat 16. At the same time, observe the reflective photoelectric speed sensor 11. When the speed of the spherical emitter 15 reaches n1 = 500 rpm, open the power solenoid valve 18. The powerful airflow sprayed from the power air intake pipe 9 acts on the spherical emitter 15. The spherical emitter 15 rotates and is quickly launched out of the launch tube 13. Observe the flight trajectory of the spherical emitter 15 and mark the landing point. At the same time, close the power solenoid valve 18 and the right-hand solenoid valve 17. Put the spherical emitter 15 into the launch tube 13, so that the strip of reflective film pasted on the spherical emitter 15 is in the horizontal direction and the middle part of the strip of reflective film in the length direction is aligned with the reflective photoelectric speed sensor 11 installed on the launch tube 13.

[0062] S2.5. Open the right-hand solenoid valve 17, and the right-hand air intake pipe sprays out airflow. The airflow acts on the spherical launcher 15, which is in a suspended state. Observe from the right side of the launch tube 13. The spherical launcher 15 rotates clockwise on the suspension seat 16. At the same time, observe the reflective photoelectric speed sensor 11. When the speed of the spherical launcher 15 reaches n2 = 800 rpm, open the power solenoid valve 18. The powerful airflow sprayed from the power air intake pipe 9 acts on the spherical launcher 15. The spherical launcher 15 rotates and is quickly launched out of the launch tube 13. Observe the flight trajectory of the ball and mark the landing point. At the same time, close the power solenoid valve 18, the right-hand solenoid valve 17, and the adjustable solenoid valve 19.

[0063] S2.6. Compare the flight trajectory and landing point of the spherical launcher 15 observed in steps S1.4, S2.4, and S2.5, analyze the principle of whether the spherical launcher 15 rotates or not, and the magnitude of the rotation speed of the spherical launcher 15, affects the flight trajectory and landing point of the spherical launcher 15, and understand the role of the Magnus effect.

[0064] S3. Observation on the influence of the rotation direction of the spherical launcher 15 on the flight trajectory

[0065] S3.1. Prepare according to steps S2.1 to S2.3, open the left-hand solenoid valve 20, the left-hand air intake pipe 14 sprays out airflow, the airflow acts on the spherical launcher 15, observe from the right side of the launch tube 13, the spherical launcher 15 rotates counterclockwise above the suspension seat 16, at the same time observe the reflective photoelectric speed sensor 11, when the speed of the spherical launcher 15 reaches n2 = 800 rpm, open the power solenoid valve 18, the powerful airflow sprayed from the power air intake pipe 9 acts on the spherical launcher 15, the spherical launcher 15 rotates and is launched quickly out of the launch tube 13, observe the flight trajectory of the ball and mark the landing point, at the same time close the power solenoid valve 18, the left-hand solenoid valve 20, the adjustable solenoid valve 19 and the photoelectric speed sensor 11;

[0066] S3.2. Compare the flight trajectory and landing point of the spherical emitter 15 observed in experimental steps S1.4, S2.5, and S3.1, analyze the principle of the influence of whether the spherical emitter 15 rotates and the direction of rotation of the spherical emitter 15 on the flight trajectory and landing point of the spherical emitter 15, and understand the role of the Magnus effect.

[0067] S4. Observation on the influence of the rotational angular velocity vector of spherical launcher 15 on the flight trajectory of spherical launcher 15

[0068] S4.1. Insert the spherical emitter 15 into the emitter tube 13, so that the strip-shaped reflective film attached to the spherical emitter 15 is in the horizontal direction and the middle part of the strip-shaped reflective film in the length direction is aligned with the reflective photoelectric speed sensor 11 installed on the emitter tube 13.

[0069] S4.2. Rotate the launch tube 13 so that the right-hand rotating air inlet pipe is exactly at the 90° mark on the angle indicator disk. Then adjust the angle between the angle indicator disk 7 and the horizontal plane so that the launch angle of the spherical launcher 15 is 75°.

[0070] S4.3. Adjust the adjustable solenoid valve 19 to slowly increase the air intake in the suspension air intake pipe 3, while observing the spherical emitter 15 located on the suspension seat 16. When the spherical emitter 15 just floats on the suspension seat 16, stop adjusting the adjustable solenoid valve 19.

[0071] S4.4. Turn on the photoelectric tachometer 11 and open the right-hand solenoid valve 17. The airflow ejected from the right-hand intake pipe 12 acts on the spherical emitter 15. Observing from the front of the emitter tube 13, the spherical emitter 15 rotates clockwise on the suspension seat 16, that is, the rotational angular velocity vector of the spherical emitter 15 points to the 0° or 360° scale line on the angle indicator disk. Observe the reflective photoelectric tachometer 11. When the rotational speed of the spherical emitter 15 reaches n2 = 800 rpm, turn on the power... The powerful airflow ejected from the solenoid valve 18 and the power intake pipe 9 acts on the spherical launcher 15. The spherical launcher 15 rotates and is rapidly launched out of the launch tube 13. The flight trajectory of the sphere is observed and the landing point is marked. At the same time, the power solenoid valve 18 and the right-hand solenoid valve 17 are closed. The strip of reflective film attached to the spherical launcher 15 is made to be horizontal, and the middle part of the length of the strip of reflective film is made to face the orientation of the reflective photoelectric speed sensor 11 installed on the launch tube 13. It is then inserted into the launch tube 13 from the upper opening.

[0072] S4.5. Rotate the launch tube 13 so that the right-hand intake pipe 12 is positioned at the 45° scale line on the angle indicating disk; open the right-hand solenoid valve 17, and the airflow ejected from the right-hand intake pipe 12 acts on the spherical launcher 15, which is in a suspended state. Observed from the right front of the launch tube 13, the spherical launcher 15 rotates clockwise above the suspension seat 16, that is, the rotational angular velocity vector of the spherical launcher 15 points to the 315° scale line on the angle indicating disk; observe the reflective photoelectric speed sensor 11, when the rotational speed of the spherical launcher 15 reaches n2 = 8... At 00 rpm, open the power solenoid valve 18. The powerful airflow ejected from the power intake pipe 9 acts on the spherical launcher 15. The spherical launcher 15 rotates and is rapidly launched from the launch tube 13. Observe the flight trajectory of the sphere and mark the landing point. At the same time, close the power solenoid valve 18 and the right-hand solenoid valve 17. Horizontally place the strip-shaped reflective film pasted on the spherical launcher 15 and make the middle part of the length of the strip-shaped reflective film face the orientation of the reflective photoelectric speed sensor 11 installed on the launch tube 13. Insert it into the launch tube 13 from the upper opening.

[0073] S4.6. Rotate the launch tube 13 so that the right-hand rotating air intake pipe 10 is positioned at the 135° scale line on the angle indicating disk; open the right-hand rotating solenoid valve 17, and the airflow ejected from the right-hand rotating air intake pipe acts on the spherical launcher 15, which is in a suspended state. Observed from the left front of the launch tube 13, the spherical launcher 15 rotates clockwise above the suspension seat 16, that is, the rotational angular velocity vector of the spherical launcher 15 points to the 45° scale line on the angle indicating disk; observe the reflective photoelectric speed sensor measurement. 11. When the rotational speed of the sphere reaches n2 = 800 rpm, the power solenoid valve 18 is opened. The powerful airflow ejected from the power intake pipe 9 acts on the spherical launcher 15. The spherical launcher 15 rotates and is rapidly launched out of the launch tube 13. The flight trajectory of the sphere is observed and the landing point is marked. At the same time, the power solenoid valve 18, the right-hand solenoid valve 17, the adjustable solenoid valve 19, the reflective photoelectric speed sensor 11, and the air compressor 5 are closed. The sphere is then reinstalled into the launch tube 13.

[0074] S4.7. Compare the flight trajectory and landing point of the spherical launcher 15 observed in experimental steps S4.4, S4.5, and S4.6, analyze the principle of the influence of the sphere's rotational angular velocity vector on the sphere's flight trajectory and landing point, and understand the role of the Magnus effect.

[0075] When conducting experiments using this invention, you can either follow the experimental steps S1, S2, S3, S4 and their respective sub-steps in sequence, or you can choose the order of the experimental contents according to the experimental method described above.

[0076] Example 2

[0077] exist Figure 1 , 3In embodiment 4, the launch tube 13 of the Magnus effect investigation experimental device is a transparent tube with a rectangular cross-section. A suspension seat 16, connected to the wall of the launch tube 13, is installed inside the launch tube 13 above the power intake pipe 9. The suspension seat 16 is an arc-shaped plate that matches the cylindrical surface of the cylindrical launcher 21. An air guide pipe 10 is located at the center of the suspension seat 16. The upper end of the power intake pipe 9 is inserted into the air guide pipe 10. The cylindrical launcher 21 is placed on the suspension seat 16. The length of the cylindrical launcher 21 is 2.4 to 3 times its radius R. The cylindrical launcher 21 is made of paulownia wood with a painted surface. A strip of reflective film, 0.5–1 cm wide, is attached along the length of the cylindrical surface of the cylindrical emitter 21. This strip provides a reflected signal to the reflective photoelectric speed sensor 11. The gap between the cylindrical emitter 21 and the inner wall of the emitter tube 13 is 3–5 mm wide, ensuring a thin layer of airflow between the cylindrical emitter 21 and the inner wall of the emitter tube 13 during rotation and launch. This prevents the friction between the cylindrical emitter 21 and the inner wall of the emitter tube 13 from affecting the movement of the cylindrical emitter 21, while also ensuring that the cylindrical emitter 21 receives sufficient launch power. Other components and their connections are the same as in Embodiment 1.

[0078] The experimental method of the Magnus effect investigation apparatus in this embodiment is the same as that in Embodiment 1.

Claims

1. An experimental apparatus for investigating the Magnus effect, characterized in that: The base is equipped with a launching mechanism, an air compression mechanism, and an air volume adjustment mechanism. The launching mechanism includes an angle indicator dial, with a launching angle adjustment mechanism at the bottom of the dial. A transparent launching tube is rotatably connected to the center of the angle indicator dial via a power intake pipe. The centerline of the launching tube coincides with the axis of the angle indicator dial. The power intake pipe passes through the center of the bottom of the launching tube and the center of the angle indicator dial. Above the power intake pipe, inside the launching tube, is a suspension seat connected to the wall of the launching tube. An air guide pipe is located at the center of the suspension seat, and the upper end of the power intake pipe is inserted into the air guide pipe. The launching body is placed on the suspension seat. There is a gap between the side walls of the cylinder. A suspended air intake pipe is provided on the lower side wall of the power air intake pipe. A left-handed air intake pipe and a right-handed air intake pipe are symmetrical about the center line in the middle of the side wall of the launch cylinder. A reflective photoelectric speed sensor is provided on the side wall of the launch cylinder below the right-handed air intake pipe. A strip-shaped reflective film is provided on the launcher to provide reflected light signals to the reflective photoelectric speed sensor. The air compression mechanism includes an air compressor and a pressure reducing valve connected to the output end of the air compressor. The air compression mechanism is connected to the left-handed air intake pipe, the right-handed air intake pipe, the power air intake pipe, and the suspended air intake pipe through an air volume regulating mechanism.

2. The experimental apparatus for investigating the Magnus effect according to claim 1, characterized in that: The launcher is a spherical launcher, and the suspension seat is a spherical crown shape.

3. The experimental apparatus for investigating the Magnus effect according to claim 1, characterized in that: The launcher is a cylindrical launcher, and the suspension seat is an arc-shaped plate.

4. The experimental apparatus for investigating the Magnus effect according to claim 2 or 3, characterized in that: The intersection of the center lines of the left-hand and right-hand air inlets with the center line of the launch tube is located below the center of the spherical launcher or the central axis of the cylindrical launcher when the launcher is stationary, and is the distance between the center of the spherical launcher or the central axis of the cylindrical launcher and the center line of the spherical launcher. R is the radius of the emitter.

5. The experimental apparatus for investigating the Magnus effect according to any one of claims 4, characterized in that: The angle between the centerline of the left-hand and right-hand air intake pipe and the centerline of the launch tube is α, where 20°≤α≤50°. The inner diameter of the left-hand or right-hand air intake pipe is 1 / 4 times the inner diameter of the power air intake pipe, and the inner diameter of the suspended air intake pipe is 1 / 8 times the inner diameter of the power air intake pipe.

6. The experimental apparatus for investigating the Magnus effect according to claim 1, characterized in that: The launch angle adjustment mechanism includes a left support column and a right support column, which are hinged to the left and right sides of the bottom of the angle indicator disk. The left support column is a fixed rod, and the right support column is a telescopic rod.

7. The experimental apparatus for investigating the Magnus effect according to claim 1, characterized in that: The air volume regulating mechanism includes an air distribution pipe, a left-hand solenoid valve, a right-hand solenoid valve, a power solenoid valve, and an adjustable solenoid valve. The air distribution pipe is equipped with an air inlet pipe and four parallel air outlet pipes. The air inlet pipe of the air distribution pipe is connected to the air compression mechanism through a pipeline. The left-hand solenoid valve, the right-hand solenoid valve, the power solenoid valve, and the adjustable solenoid valve are respectively installed on the four air outlet pipes and are connected to the left-hand air inlet pipe, the right-hand air inlet pipe, the power air inlet pipe, and the suspended air inlet pipe through pipelines.

8. The experimental method of the Magnus effect investigation experimental apparatus according to claim 7, characterized in that, Includes the following steps: S1. Observation of the launcher's flight trajectory when the launcher is not rotating. S1.

1. Open the power solenoid valve, right-hand solenoid valve, and left-hand solenoid valve to start the air compressor mechanism, adjust the output pressure of the air compressor mechanism to the predetermined value, and then close the power solenoid valve, right-hand solenoid valve, and left-hand solenoid valve. S1.

2. The launcher is loaded into the launch tube from the top opening; S1.

3. Rotate the launch tube so that the right-hand air intake pipe is exactly at the 0° mark on the angle indicator disc, and then adjust the angle between the angle indicator disc and the horizontal plane so that the launch angle of the launcher is 70° to 80°. S1.

4. Open the power solenoid valve. The powerful airflow from the power intake pipe acts on the launcher, and the launcher quickly launches the launch tube. Observe the flight trajectory of the launcher and mark the landing point. At the same time, close the power solenoid valve. S2. Observation on the effect of the launcher's rotational speed on its flight trajectory S2.

1. Insert the emitter into the emitter tube, so that the strip of reflective film attached to the emitter is in the horizontal direction and the middle part of the strip of reflective film along its length is aligned with the reflective photoelectric speed sensor installed on the emitter tube. S2.

2. Rotate the launch tube so that the right-hand air intake pipe is exactly at the 0° mark on the angle indicator disc. Then adjust the angle between the angle indicator disc and the horizontal plane so that the launch angle of the launcher is 70° to 80°. S2.

3. Adjust the adjustable solenoid valve to slowly increase the air intake in the suspension air intake pipe, while observing the launcher located on the suspension seat. When the launcher just floats up on the suspension seat, stop adjusting the adjustable solenoid valve. S2.

4. Turn on the reflective photoelectric speed sensor and open the right-hand solenoid valve. The right-hand air intake pipe sprays out airflow, which acts on the launcher. Observe from the right side of the launch tube. The launcher rotates clockwise. At the same time, observe the reflective photoelectric speed sensor. When the speed of the launcher reaches n1 rpm, 400≤n1≤600, open the power solenoid valve. The powerful airflow sprayed from the power air intake pipe acts on the launcher. The launcher rotates and is launched out of the launch tube quickly. Observe the flight trajectory of the launcher and mark the landing point. At the same time, close the power solenoid valve and the right-hand solenoid valve. Put the launcher into the launch tube and make the strip of reflective film attached to the launcher horizontal and the middle part of the length of the strip of reflective film aligned with the reflective photoelectric speed sensor installed on the launch tube. S2.

5. Open the right-hand solenoid valve, and the right-hand intake pipe will eject airflow. The airflow acts on the launcher. Observing from the right side of the launch tube, the launcher rotates clockwise on the suspension seat. At the same time, the reflective photoelectric speed sensor measures the launcher's rotation speed. When the launcher's rotation speed reaches n2 rpm, n2 > n1. Open the power solenoid valve, and the powerful airflow ejected from the power intake pipe acts on the launcher. The launcher rotates and is launched quickly out of the launch tube. Observe the trajectory of the sphere and mark the landing point. At the same time, close the power solenoid valve, the right-hand solenoid valve, and the adjustable solenoid valve. S2.

6. Compare the flight trajectory and landing point of the launcher observed in steps S1.4, S2.4, and S2.5, analyze the principle of the influence of whether the launcher rotates and the magnitude of the launcher's rotation speed on the flight trajectory and landing point, and understand the role of the Magnus effect. S3. Observation of the effect of launcher rotation direction on flight trajectory S3.

1. Prepare according to steps S2.1 to S2.3, open the left-hand solenoid valve, the left-hand air intake pipe sprays out airflow, the airflow acts on the launcher, observe from the right side of the launch tube, the launcher rotates counterclockwise on the suspension seat, at the same time observe the reflective photoelectric speed sensor, when the rotation speed of the ball reaches n2 rpm, open the power solenoid valve, the powerful airflow sprayed from the power air intake pipe acts on the launcher, the launcher rotates and is launched out of the launch tube quickly, observe the flight trajectory of the launcher and mark the landing point, at the same time close the power solenoid valve, the right-hand solenoid valve, the adjustable solenoid valve and the reflective photoelectric speed sensor; S3.

2. Compare the flight trajectory and landing point of the launcher observed in experimental steps S1.4, S2.5, and S3.1, analyze the principle of the influence of whether the launcher rotates and the direction of rotation on the flight trajectory and landing point, and understand the role of the Magnus effect. S4. Observation of the influence of the launcher's rotational angular velocity vector on the launcher's flight trajectory S4.

1. Insert the emitter into the emitter tube, so that the strip of reflective film attached to the emitter is in the horizontal direction and the middle part of the strip of reflective film along its length is aligned with the reflective photoelectric speed sensor installed on the emitter tube. S4.

2. Rotate the launch tube so that the right-hand rotating air inlet pipe is exactly at the 90° mark on the angle indicator disc. Then adjust the angle between the angle indicator disc and the horizontal plane so that the launch angle of the launcher is 70° to 80°. S4.

3. Adjust the adjustable solenoid valve to slowly increase the air intake in the suspension air intake pipe, while observing the launcher located on the suspension seat. When the launcher just floats on the suspension seat, stop adjusting the adjustable solenoid valve. S4.

4. Turn on the reflective photoelectric speed sensor and open the right-hand solenoid valve. The airflow ejected from the right-hand intake pipe acts on the launcher. When viewed from the front of the launch tube, the launcher rotates clockwise on the suspension seat. That is, the rotational angular velocity vector of the launcher points to the 0° or 360° scale line on the angle indicator disk. Observe the reflective photoelectric speed sensor. When the speed of the transmitter reaches n2 rpm, open the power solenoid valve. The powerful airflow from the power intake pipe acts on the transmitter, which rotates and is quickly launched out of the launch tube. Observe the flight trajectory of the transmitter and mark the landing point. At the same time, close the power solenoid valve and the right-hand solenoid valve, and put the transmitter into the launch tube. Make sure that the strip of reflective film attached to the transmitter is in the horizontal direction and the middle part of the strip of reflective film along its length is aligned with the reflective photoelectric speed sensor installed on the launch tube. S4.

5. Rotate the launch tube so that the right-hand intake pipe is positioned at the α angle scale line on the angle indicator disk, 0° < α < 90°; open the right-hand solenoid valve, and the airflow from the right-hand intake pipe acts on the launcher. Observing from the right front of the launch tube, the launcher rotates clockwise on the suspension seat, that is, the angular velocity vector of the launcher points to the 270° + α scale line on the angle indicator disk; observe the reflective photoelectric speed sensor. When the launcher's speed reaches n2 rpm, open the power solenoid valve. The powerful airflow from the power intake pipe acts on the launcher, and the launcher rotates and is quickly launched out of the launch tube. Observe the launcher's flight trajectory and mark the landing point. At the same time, close the power solenoid valve and the right-hand solenoid valve, and put the launcher into the launch tube, so that the strip of reflective film attached to the launcher is in the horizontal direction and the middle part of the strip of reflective film along its length is aligned with the reflective photoelectric speed sensor installed on the launch tube. S4.

6. Rotate the launch tube so that the right-hand intake pipe is positioned at the β angle scale line on the angle indicator disk, 90° < β < 180°; open the right-hand solenoid valve, and the airflow from the right-hand intake pipe acts on the launcher. Observing from the left front of the launch tube, the launcher rotates clockwise on the suspension seat, that is, the rotational angular velocity vector of the launcher points to the β-90° scale line on the angle indicator disk; observe the reflective photoelectric speed sensor. When the launcher's rotational speed reaches n2 rpm, open the power solenoid valve. The powerful airflow from the power intake pipe acts on the launcher, and the launcher rotates and is rapidly launched out of the launch tube. Observe the trajectory of the sphere and mark the landing point. At the same time, close the power solenoid valve, the right-hand solenoid valve, the adjustable solenoid valve, the reflective photoelectric speed sensor, the air compression mechanism, and reinstall the launcher back into the launch tube. S4.

7. Compare the flight trajectory and landing point of the launcher observed in experimental steps S4.4, S4.5, and S4.6, analyze the principle of the influence of the launcher's rotational angular velocity vector on the launcher's flight trajectory and landing point, and understand the role of the Magnus effect.

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