Rotary drum sail thrust measuring system and measuring method based on wind pressure monitoring

Abstract

The invention provides a rotating cylinder sail thrust measuring system and measuring method based on wind pressure monitoring. The measuring system is used for measuring the thrust of the rotary cylinder sail, a sensing unit of the measuring system comprises an environment monitoring sensor, a wind pressure sensor array and a position synchronization sensor, the environment monitoring sensor is used for monitoring the real-time wind field condition of the environment where the rotary cylinder sail is located, and the wind pressure sensor array comprises a plurality of wind pressure sensors; the wind pressure sensors are arranged on the outer cylinder surface of the rotary cylinder sail in a preset matrix mode, can rotate along with the outer cylinder and are used for monitoring wind pressure values of all positions of the outer cylinder surface in real time; the position synchronization sensor is used for monitoring the angle position of the wind pressure sensor in real time. The wind pressure sensor array is arranged on the surface of the outer cylinder, wind pressure distribution on the surface of the outer cylinder can be directly monitored, the physical quantity of the most source is directly measured, and thrust measurement calculation is conducted according to obtained pressure distribution data. Indirect estimation by measuring the power change of the rotary cylinder sail main engine is avoided, and the measurement precision is improved.

Description

Technical Field

[0001] This invention relates to the field of marine energy conservation technology, and more specifically, to a rotary sail thrust measurement system and method based on wind pressure monitoring. Background Technology

[0002] Rotary sails, as an energy-saving device utilizing the Magnus effect, are widely used in modern ships to reduce fuel consumption and carbon emissions. Rotary sails use an electric motor to drive a large-diameter outer tube to rotate. Utilizing the Magnus effect, a pressure difference is created on both sides of the outer tube, generating thrust perpendicular to the wind direction to provide auxiliary propulsion for the ship. Accurately measuring the real-time thrust generated by rotary sails under complex sea conditions is crucial for evaluating their energy efficiency and optimizing control strategies.

[0003] However, current methods for measuring the thrust of rotary sails suffer from the following problems: 1. Indirect estimation by measuring changes in main engine power results in significant lag, low accuracy, and an inability to isolate the influence of other factors; 2. Installing large measuring sensors at the base of the rotary sail requires significant structural modifications, is costly, and the sensors are easily damaged in harsh marine environments; 3. Installing strain gauges at the main stress points of the outer cylinder and inferring the force on the rotary cylinder from the strain changes in the stressed structure requires establishing an accurate "strain-thrust" mathematical model. This necessitates complex on-site calibration of the entire system after installation, such as statically loading the rotary cylinder with a known force or torque, a time-consuming, expensive, and difficult process; 4. Limited data dimensionality: Existing methods can only obtain a total thrust value and cannot acquire detailed pressure distribution on the rotary cylinder surface, thus hindering in-depth analysis of the Magnus effect mechanism. Summary of the Invention

[0004] In view of this, the present invention aims to propose a thrust measurement system and method for a rotary sail based on wind pressure monitoring, so as to solve the problems in the prior art that it is difficult to directly measure the thrust on the outer surface of the outer cylinder, and that the measurement process is complicated and the measurement accuracy is poor.

[0005] To achieve the above objectives, the technical solution of the present invention is implemented as follows:

[0006] On one hand, this invention proposes a thrust measurement system for a rotary sail based on wind pressure monitoring, used to measure the thrust of a rotary sail. The measurement system includes a sensing unit, a data acquisition and processing unit, and a signal transmission unit. The signal transmission unit is connected to the sensing unit and the data acquisition and processing unit respectively. The sensing unit includes an environmental monitoring sensor, a wind pressure sensor array, and a position synchronization sensor. The environmental monitoring sensor is set adjacent to the rotary sail and is used to monitor the real-time wind field conditions of the environment in which the rotary sail is located. The wind pressure sensor array includes multiple wind pressure sensors arranged in a predetermined matrix on the outer surface of the rotary sail and can rotate with the outer shell to monitor the wind pressure values ​​at various points on the outer shell surface in real time. The position synchronization sensor is set on the rotary sail and is used to monitor the angular position of the wind pressure sensor in real time.

[0007] Furthermore, the rotary sail includes a base, an outer cylinder, and an inner tower. The inner tower is connected to the top of the base, and the outer cylinder is fitted over the outer part of the inner tower. The outer cylinder is rotatably connected to the inner tower about a rotation axis.

[0008] Furthermore, the predetermined matrix form of the wind pressure sensor array is as follows: the number of distribution layers of wind pressure sensors along the height direction of the outer cylinder is m, and the number of distributions along the circumference in the same height direction of the outer cylinder is p, where p=1 or p>1; when p=1, one wind pressure sensor is arranged circumferentially at the same height of the outer cylinder, and when p>1, multiple wind pressure sensors are arranged circumferentially at the same height.

[0009] Furthermore, m≥5, p≥36.

[0010] Furthermore, the wind pressure sensor is embedded in the outer surface of the outer cylinder, and the probe of the wind pressure sensor faces away from the inner tower of the vortex sail, and the probe should be flush with the outer surface of the outer cylinder.

[0011] Furthermore, the position synchronization sensor is a photoelectric switch assembly or an incremental encoder. The photoelectric switch assembly includes a photoelectric switch and a reflective marker. The photoelectric switch is disposed on the inner tower, and the reflective marker is disposed on the inner wall of the outer cylinder. The probe of the photoelectric switch faces the reflective marker.

[0012] Furthermore, the signal transmission unit is connected to the sensing unit and the data acquisition and processing unit via transmission cables, and multiple wind pressure sensors are also connected to the transmission cables accordingly.

[0013] Furthermore, the inner wall of the outer cylinder is connected to the tapered plate, and the upper bearing assembly is driven to the tapered plate. The signal transmission unit includes a transmission cable, a wind pressure junction box, and a slip ring. The wind pressure junction box is located at the center of the tapered plate and is used to centrally connect the transmission cables of each wind pressure sensor, and then connect them to the slip ring after they are combined into a single transmission cable. The slip ring is located on the main shaft of the upper bearing assembly and is used to realize the signal and power transmission of the wind pressure sensor array and the data acquisition and processing unit.

[0014] On the other hand, the present invention also proposes a method for measuring the thrust of a rotary sail based on wind pressure monitoring. The measurement method uses the aforementioned thrust measurement system and includes the following steps:

[0015] S1. At the same time, the environmental monitoring sensor, wind pressure sensor array and position synchronization sensor monitor in real time, start signal acquisition, and transmit to the data acquisition and processing unit;

[0016] S2. Determine if p=1 is satisfied. If so, use the time integration algorithm.

[0017]

[0018] Among them, F t The thrust on the rotating cylinder; m is the number of layers of the wind pressure sensor array along the height of the outer cylinder; i is the index of the height layer where the wind pressure sensor is located (i is selected from any value from 1 to m); n is the number of sampling points in one circumference; j is the circumferential angle index of the sampling point (j is selected from any value from 1 to n); P i，j Let θ be the pressure value at the i-th height layer and the j-th sampling point; j Δθ is the angle of the j-th sampling point (relative to the bow); Δθ is the angle between two adjacent sampling points of the same wind pressure sensor (2π / n radians); Δh i Let be the equivalent height represented by the i-th height layer;

[0019] Determine if p > 1 is satisfied; if so, use the space integration algorithm.

[0020]

[0021] Among them, F t The thrust on the rotating cylinder; m is the number of layers of the wind pressure sensor array distributed along the height of the outer cylinder; i is the index of the height layer where the wind pressure sensor is located (i is selected from any value from 1 to m); p is the number of wind pressure sensors installed in the same circumference; k is the index of the circumferential position of the wind pressure sensor (k is selected from any value from 1 to p); P i，kθi represents the pressure value at the k-th wind pressure sensor at the i-th altitude level; θk represents the angle of the k-th wind pressure sensor (relative to the bow); Δθ' represents the angle between two adjacent sampling points of the same wind pressure sensor (2π / n radians); Δhi represents the equivalent height represented by the i-th altitude level.

[0022] S3. The monitored data is stored in the data storage and display unit, and the environmental conditions measured at each time and the calculated thrust, drag and resultant force are displayed in the data storage and display unit.

[0023] When p=1,

[0024]

[0025]

[0026] When p > 1

[0027]

[0028]

[0029] Among them, F d As resistance, F r For the sake of combined efforts.

[0030] Compared with existing technologies, the rotary sail thrust measurement system and method based on wind pressure monitoring described in this invention have the following advantages:

[0031] (1) Real-time accurate measurement: Real-time, online and direct measurement of the thrust of the rotary sail is realized, with high measurement accuracy;

[0032] (2) Comprehensive data acquisition: It can not only obtain the total thrust, but also obtain detailed surface pressure distribution, providing rich data for aerodynamic analysis;

[0033] (3) High reliability: The system adopts a distributed wind pressure sensor array, and the failure of a single sensor does not affect the overall function of the system;

[0034] (4) Strong engineering applicability: The sampling industrial-grade professional PLC operation module and high-speed module replace the data acquisition instrument commonly used in the laboratory to collect and process high-frequency, large-volume wind pressure data. It is easy to integrate with the rotary sail control system and has high reliability.

[0035] (5) Two thrust integration algorithms based on time and space integration are proposed, which are more applicable. Attached Figure Description

[0036] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0037] Figure 1 This is a schematic diagram of the overall structure of the thrust measurement system described in this invention;

[0038] Figure 2 This is a schematic diagram of the structure of the rotary sail and thrust measurement system used in conjunction with the present invention.

[0039] Figure 3 This is a schematic diagram of the wind pressure sensor array arrangement under the condition of p=1 as described in this invention;

[0040] Figure 4 This is a schematic diagram of the wind pressure sensor array arrangement under the condition of p > 1 as described in this invention;

[0041] Figure 5 This is a schematic diagram showing the distribution of wind pressure data collected by the wind pressure sensors at heights of 2.5m and 22.5m after rotating one revolution in Embodiment 1 of the present invention.

[0042] Figure 6 These are the thrust values ​​calculated at different heights in Embodiment 1 of the present invention.

[0043] Explanation of reference numerals in the attached figures:

[0044] 1. Data acquisition and processing unit; 2. Data storage and display unit; 3. Outer cylinder; 4. Inner tower; 5. Base; 6. Upper bearing assembly; 7. Limiting wheel; 8. Environmental monitoring sensor; 9. Wind pressure sensor array; 10. Photoelectric switch; 11. Reflective marker; 12. Transmission cable; 13. Wind pressure junction box; 14. Tapered plate; 15. Slip ring; 16. Main shaft. Detailed Implementation

[0045] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. In addition, the orientations involved in the following specific embodiments are briefly explained: the directions or positional relationships indicated by "front", "rear", "up", "down", "left", "right", "top", "bottom", etc. mentioned in the embodiments refer to the orientations or positional relationships shown in the accompanying drawings, and the term "on" means directly or indirectly supported by the element.

[0046] It should be noted that, in the description of this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, an electrical connection, or a connection that allows for communication; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0047] like Figures 1-2 As shown, the present invention discloses a wind pressure monitoring-based thrust measurement system for a rotary sail, used to measure the thrust of a rotary sail. The measurement system includes a sensing unit, a data acquisition and processing unit 1, and a signal transmission unit. The signal transmission unit is connected to the sensing unit and the data acquisition and processing unit 1 respectively. The sensing unit includes an environmental monitoring sensor 8, a wind pressure sensor array 9, and a position synchronization sensor. The environmental monitoring sensor 8 is arranged adjacent to the rotary sail and is used to monitor the real-time wind field conditions of the environment in which the rotary sail is located. The wind pressure sensor array 9 includes multiple wind pressure sensors arranged in a predetermined matrix on the surface of the outer cylinder 3 of the rotary sail and can rotate with the outer cylinder 3 to monitor the wind pressure values ​​at various points on the surface of the outer cylinder 3 in real time. The position synchronization sensor is arranged on the rotary sail and is used to monitor the angular position of the wind pressure sensor in real time.

[0048] The sensing unit is used to transmit the monitored signal to the data acquisition and processing unit 1 via the signal transmission unit, and provide relevant indicators for thrust measurement and calculation.

[0049] This invention, by setting a wind pressure sensor array 9 on the surface of the outer cylinder 3, can directly monitor the wind pressure distribution on the surface of the outer cylinder 3, directly measuring the most fundamental physical quantity—the wind pressure distribution on the surface of the outer cylinder 3—and calculate the thrust based on the obtained pressure distribution data. This avoids indirect estimation by measuring the power change of the rotary sail main engine, improving measurement accuracy and fundamentally avoiding the errors and lag of indirect measurement.

[0050] The environmental monitoring sensor 8 described in this invention is positioned close to the rotary sail, meaning that the environmental monitoring sensor 8 is placed near the rotary sail, as long as it can accurately monitor the wind field conditions where the rotary sail is located. The environmental monitoring sensor 8 includes at least an anemometer, a temperature and humidity meter, and a barometer.

[0051] The rotary sail includes a base 5, an outer cylinder 3, and an inner tower 4. The inner tower 4 is connected above the base 5, and the outer cylinder 3 is sleeved on the outside of the inner tower 4. The outer cylinder 3 is rotatably connected to the inner tower 4 around a rotation axis.

[0052] The inner wall of the outer cylinder 3 is provided with a limiting wheel 7 to restrain the high-speed rotating outer cylinder 3, prevent it from shaking or vibrating harmfully, and transfer the huge impact load to the base 5 and the hull.

[0053] The inner wall of the outer cylinder 3 is connected to the tapered plate 14, and the upper bearing assembly 6 is driven to the tapered plate 14. The motor of the upper bearing assembly 6 provides power for the rotation of the spinning drum sail. The tapered plate 14, as a transmission component, enables the transmission connection between the motor and the outer cylinder 3, driving the outer cylinder 3 to rotate, and the tapered plate 14 helps to maintain the radial position of the rotating outer cylinder 3 relative to the inner tower 4.

[0054] The predetermined matrix form of the wind pressure sensor array 9 is as follows: the number of layers of wind pressure sensors distributed along the height direction of the outer cylinder 3 is m, m≥5, and the number of sensors distributed along the circumferential direction at the same height direction of the outer cylinder 3 is p, p=1 or p>1.

[0055] When p=1, one wind pressure sensor is arranged circumferentially at the same height on the outer cylinder 3. Preferably, the wind pressure sensors at different heights are located at the same position on the circumference at different heights, that is, the projections of the wind pressure sensors at different heights on the base 5 coincide.

[0056] When p > 1, multiple wind pressure sensors are arranged circumferentially at the same height. Preferably, p ≥ 36. By distributing the wind pressure sensors in the height and circumferential direction of the outer cylinder 3, it is ensured that all parts of the outer cylinder 3 can be covered, and the wind pressure values ​​at different locations of the outer cylinder 3 can be monitored, which helps to improve the accuracy of thrust measurement.

[0057] As a preferred example of the present invention, the wind pressure sensor is embedded in the outer surface of the outer cylinder 3, and the probe of the wind pressure sensor faces away from the inner tower 4. The probe should be flush with the outer surface of the outer cylinder 3 to ensure that the pressure-sensing surface of the wind pressure sensor is conformal to the streamlined surface of the outer cylinder 3, thereby minimizing interference with the local flow field, ensuring the authenticity and accuracy of the monitored wind pressure data, and also improving the accuracy of thrust measurement.

[0058] The wind pressure sensor is equipped with a signal conditioning amplifier to amplify and filter the signal detected by the wind pressure sensor. The signal conditioning amplifier and the wind pressure sensor are connected together and installed on the outer surface of the outer cylinder 3, or both are connected to the outer surface of the outer cylinder 3 separately, with the signal conditioning amplifier located at the rear end of the wind pressure sensor.

[0059] As a specific example of the present invention, the wind pressure sensor is a high-frequency dynamic pressure sensor, and the usable frequency should be greater than 5 times the sampling frequency.

[0060] As another specific example of the present invention, the wind pressure sensor is a gauge pressure type or an absolute pressure type sensor. The measurement accuracy of the gauge pressure type should be better than 0.5%FS (full scale), and the measurement accuracy of the absolute pressure type should be better than 0.25%FS (full scale).

[0061] As another specific example of the present invention, the wind pressure sensor is a miniature pressure sensor, which facilitates high-density array distribution, reduces interference with the original flow field on the surface of the outer cylinder 3, and reduces the impact on the mass of the outer cylinder 3.

[0062] The position synchronization sensor of this invention is used to monitor the angle θ of the sampling point, i.e., the angle between the wind pressure sensor and the bow direction. The position synchronization sensor can be a photoelectric switch assembly or an incremental encoder. The photoelectric switch assembly includes a photoelectric switch 10 and a reflective marker 11. The photoelectric switch 10 is disposed on the inner tower 4, and the reflective marker 11 is disposed on the inner wall of the outer cylinder 3. The probe of the photoelectric switch 10 faces the reflective marker 11, and a layer of black paint is applied near the inner wall of the outer cylinder 3 where the reflective marker 11 is located to enhance the reflective effect. The photoelectric switch 10 is used to emit a laser or red light signal, which is received by the reflective marker 11 located on the inner wall of the outer cylinder 3. Therefore, it is necessary to ensure that the photoelectric switch 10 and the reflective marker 11 are at the same height.

[0063] When p=1, the reflective marker 11 is positioned directly below the wind pressure sensor. When the reflective marker 11 rotates with the outer cylinder 3 to the position where it receives the signal from the photoelectric switch 10, it indicates that the reflective marker 11 and the wind pressure sensor have rotated to the same position as the photoelectric switch 10. Since the positions of the photoelectric switch 10 and the bow are fixed, the angle θ of the wind pressure sensor at this sampling point can be reflected by the angle between the photoelectric switch 10 and the bow. For ease of subsequent calculations, θ=0° is defined for this position. This position is used as a reference point to determine the positions of other sampling points.

[0064] When p > 1, the reflective marker 11 is positioned directly below any wind pressure sensor on the same circumference, and the position of that wind pressure sensor is used as the calibration position. When the reflective marker 11 rotates with the outer cylinder 3 to the position where it receives the signal from the photoelectric switch 10, it indicates that the reflective marker 11 and the wind pressure sensor have rotated to the same position as the photoelectric switch 10. The angle θ of the wind pressure sensor at this sampling point is reflected by the angle between the photoelectric switch 10 and the bow. For ease of subsequent calculation, θ = 0° is defined for this position. Simultaneously, since the arrangement of wind pressure sensors on the same circumference is fixed, the angle θ of other wind pressure sensors at this sampling point can be determined accordingly. The position of the wind pressure sensor in this case is used as a reference point to determine the positions of other sampling points.

[0065] Specifically, black paint is applied to the area 80-100mm above and below the reflective marker 11.

[0066] Define the diameter of the light spot formed on the inner wall of the outer cylinder 3 when the photoelectric switch 10 is turned on as D. light Define the angle between two sampling points formed by two adjacent sampling times of the same wind pressure sensor as Δθ, and D light <2△θ.

[0067] The switching frequency of the photoelectric switch 10 is greater than or equal to the sampling frequency of the wind pressure sensor.

[0068] The value of Δθ can be determined by those skilled in the art based on experience. For example, if the number of sampling points in one circle is n=180, that is, 180 samplings in the same circumferential direction, then Δθ=2° in order to achieve sampling in the same circumferential direction. If the number of sampling points in one circle is n=360, that is, 360 samplings in the same circumferential direction, then Δθ=1° in order to achieve sampling in the same circumferential direction.

[0069] The signal transmission unit includes a transmission cable 12, a wind pressure junction box 13, and a slip ring 15. The wind pressure junction box 13 is located at the center of the tapered plate 14 and is used to centrally connect the transmission cables 12 of each wind pressure sensor, and then connect them to the slip ring 15 after they are combined into a single transmission cable. The slip ring 15 is located on the main shaft 16 of the upper bearing assembly 6 and can rotate synchronously with the upper bearing assembly 6 to realize the signal and power transmission between the wind pressure sensor array 9 and the data acquisition and processing unit 1.

[0070] Since the wind pressure sensor array 9 is rotating while the data acquisition and processing unit 1 is fixed, signal and power transmission between the two can be achieved through the slip ring 15. The connection between the rotating wind pressure sensor array 9 and the fixed data acquisition and processing unit 1 using the slip ring 15 is existing technology and will not be elaborated upon here.

[0071] The number of channels in the slip ring 15 is greater than or equal to the number of channels required by the wind pressure sensor array 9.

[0072] The signal transmission unit is connected to the sensing unit and the data acquisition and processing unit 1 respectively via transmission cable 12, and multiple wind pressure sensors are also connected to the transmission cable 12 respectively.

[0073] The thrust measurement system of the present invention also includes a data storage and display unit 2, which is connected to the data acquisition and processing unit 1 via a transmission cable 12, and is used to store and display the relevant signal data obtained for subsequent experimental analysis.

[0074] As a specific example of the present invention, the data storage and display unit 2 includes an industrial display for real-time display of calculated thrust, drag, resultant force, and measured historical data; a host computer software module for providing data analysis and visualization functions; and a storage device for storing raw data and data processing results. The storage device can be a memory card or a hard disk.

[0075] As a specific example of the present invention, the data acquisition and processing unit 1 includes a professional PLC operation module for controlling and executing the core data processing algorithm of the measurement system; and a high-speed PLC module for high-frequency, real-time acquisition of data monitored by the sensing unit.

[0076] The measurement method of the present invention uses the above-described thrust measurement system, and the measurement method includes the following steps:

[0077] S1. At the same time, the environmental monitoring sensor 8, the wind pressure sensor array 9, and the position synchronization sensor monitor in real time, start signal acquisition, and transmit to the data acquisition and processing unit 1;

[0078] Specifically, in step S1, environmental information such as wind speed, wind direction, temperature, and humidity of the test site is measured by environmental monitoring sensor 8, wind pressure data at multiple locations on the surface of the outer cylinder 3 is collected by wind pressure sensor array 9, and the angular position of the wind pressure sensor is monitored and collected synchronously by position synchronization sensor.

[0079] In the data acquisition and processing unit 1, the signal data monitored by the sensing unit is received. When the position synchronization sensor receives the signal, the photoelectric switch 10 corresponds to the normally open signal, and the incremental encoder corresponds to the Z signal. Then, the core data processing algorithm is executed to calculate the thrust, drag and resultant force.

[0080] S2. Determine if p=1 is satisfied. If so, use the time integration algorithm.

[0081]

[0082] Among them, F t The thrust on the rotating cylinder; m is the number of layers of the wind pressure sensor array 9 distributed along the height direction of the outer cylinder 3; i is the height layer index of the wind pressure sensor (i is selected from any value from 1 to m); n is the number of sampling points in one circle; j is the circumferential angle index of the sampling point (j is selected from any value from 1 to n); P i，j Let θ be the pressure value at the i-th height layer and the j-th sampling point; j Δθ is the angle of the j-th sampling point (relative to the bow); Δθ is the angle between two adjacent sampling points of the same wind pressure sensor (2π / n radians); Δh i Let be the equivalent height represented by the i-th height layer;

[0083] The equivalent height represents the height distance in the vertical direction at which the thrust on the rotating drum is equivalent to the thrust calculated using the i-th height layer. The specific value can be determined by those skilled in the art based on experience.

[0084]

[0085]

[0086] Among them, F d As resistance, F r For combined efforts;

[0087] Determine if p > 1 is satisfied; if so, use the space integration algorithm.

[0088]

[0089] Among them, F t The thrust on the rotating cylinder is m; the number of layers of the wind pressure sensor array 9 distributed along the height direction of the outer cylinder 3 is m; i is the height layer index of the wind pressure sensor (i is selected from any value from 1 to m); p is the number of wind pressure sensors installed in the same circumference; k is the circumferential position index of the wind pressure sensor (k is selected from any value from 1 to p); P i，k θi represents the pressure value at the k-th wind pressure sensor at the i-th altitude level; θk represents the angle of the k-th wind pressure sensor (relative to the bow); Δθ' represents the angle between two adjacent sampling points of the same wind pressure sensor (2π / n radians); Δhi represents the equivalent height represented by the i-th altitude level.

[0090]

[0091]

[0092] Among them, F d As resistance, F r For combined efforts;

[0093] Specifically, in step S2, the angle-pressure correspondence of the wind pressure sensor is established based on the synchronized signal and sampling frequency of the position synchronization sensor. The wind pressure data of the wind pressure sensor is integrated using an integration algorithm, and the thrust F on the surface of the outer cylinder 3 is calculated by projecting it along the ship's sailing direction and perpendicular to the ship's sailing direction. t Resistance F d , resultant force F r .

[0094] For the case where only one wind pressure sensor is arranged circumferentially at the same height on the outer cylinder 3, i.e., p=1, such as Figure 3 As shown, Figure 3The position j=1 is where only one wind pressure sensor is arranged circumferentially at the same height as the outer cylinder 3. The integration algorithm adopts the time integration algorithm, and the thrust F t This represents the average thrust during one revolution of the outer cylinder 3.

[0095] For the case where multiple wind pressure sensors are arranged circumferentially at the same height on the outer cylinder 3, i.e., p > 1, such as Figure 4 As shown, Figure 4 p wind pressure sensors are distributed circumferentially at the same height along the outer cylinder 3. The integration algorithm adopts a spatial integration algorithm, and the thrust F t This represents the spatial average value along the circumference of the outer cylinder 3 at each usage time.

[0096] This invention can also employ other numerical integration methods, such as linear integration algorithms, curve fitting integration algorithms, Gaussian integration algorithms, etc.

[0097] S3. The monitored data is stored in the data storage and display unit 2, and the environmental conditions measured at each time and the calculated thrust, drag and resultant force are displayed in the data storage and display unit 2.

[0098] The rotary sail thrust measurement system and method based on wind pressure monitoring, as described in this invention, have the following advantages:

[0099] (1) Real-time accurate measurement: Real-time, online and direct measurement of the thrust of the rotary sail is realized, with high measurement accuracy;

[0100] (2) Comprehensive data acquisition: It can not only obtain the total thrust, but also obtain detailed surface pressure distribution, providing rich data for aerodynamic analysis;

[0101] (3) High reliability: The system adopts a distributed wind pressure sensor array, and the failure of a single sensor does not affect the overall function of the system;

[0102] (4) Strong engineering applicability: The sampling industrial-grade professional PLC operation module and high-speed module replace the data acquisition instrument commonly used in the laboratory to collect and process high-frequency, large-volume wind pressure data. It is easy to integrate with the rotary sail control system and has high reliability.

[0103] (5) Two thrust integration algorithms based on time and space integration are proposed, which are more applicable.

[0104] Example 1

[0105] The thrust measurement system and method of this invention are applied to a 5*35m (5m in diameter and 35m in height) rotary sail.

[0106] Seven wind pressure sensors are arranged along the height direction on the outer cylinder 3 of the rotary sail, with one wind pressure sensor at each height level. The wind pressure sensors are absolute pressure sensors. The distribution of the wind pressure sensors along the height direction of the outer cylinder 3 is as follows: 2.5m, 7.5m, 12.5m, 17.5m, 22.5m, 27.5m, and 32.5m, i.e., m=7 layers, corresponding to the height layer indices i=1, 2, 3, 4, 5, 6, and 7 respectively.

[0107] The rotational speed of the rotary sail is controlled at 180 rpm, and the speed is kept stable. The sampling frequency of the PLC high-speed module is set to 108 Hz, that is, the wind pressure sensor array 9 collects data once every 10° interval, so n=36.

[0108] After the monitoring is completed, according to the results of the data storage and display unit 2, during a certain period of time when the outer cylinder 3 rotates once, the anemometer of the environmental monitoring sensor 8 detects an ambient wind speed of 25 m / s and a wind direction of 90°, the temperature and humidity meter detects an ambient temperature of 12℃ and a relative humidity of 50%, and the air pressure monitor detects an ambient atmospheric pressure of 101087 Pa.

[0109] Taking heights of 2.5m and 22.5m as examples, the wind pressure data collected by the wind pressure sensors at these two heights are as follows: Figure 5 As shown. Based on the wind pressure data monitored by wind pressure sensors at different altitudes and the angular position information monitored by the position synchronization sensor, the thrust value is calculated using the formula corresponding to p=1, as shown below. Figure 6 As shown, the total thrust of the rotary sail under this operating condition is 448 kN. The thrust value calculated according to the formula differs from the simulated thrust value under the corresponding operating condition by less than 5%, demonstrating the effectiveness and accuracy of the thrust measurement system and method of this invention.

[0110] While the present invention has been disclosed above, it is not limited thereto. Any person skilled in the art can make various alterations and modifications without departing from the spirit and scope of the invention; therefore, the scope of protection of the present invention should be determined by the scope defined in the claims.

Claims

1. A system for measuring the thrust of a rotary sail based on wind pressure monitoring, used to measure the thrust of a rotary sail, characterized in that, The measurement system includes a sensing unit, a data acquisition and processing unit (1), and a signal transmission unit. The signal transmission unit is connected to the sensing unit and the data acquisition and processing unit (1) respectively. The sensing unit includes an environmental monitoring sensor (8), a wind pressure sensor array (9), and a position synchronization sensor. The environmental monitoring sensor (8) is set close to the rotary sail and is used to monitor the real-time wind field conditions of the environment where the rotary sail is located. The wind pressure sensor array (9) includes multiple wind pressure sensors, which are set in a predetermined matrix on the surface of the outer cylinder (3) of the rotary sail and can rotate with the outer cylinder (3) to monitor the wind pressure value at various points on the surface of the outer cylinder (3) in real time. The position synchronization sensor is set on the rotary sail and is used to monitor the angular position of the wind pressure sensor in real time.

2. The thrust measurement system according to claim 1, characterized in that, The rotary sail includes a base (5), an outer cylinder (3) and an inner tower (4). The inner tower (4) is connected above the base (5), and the outer cylinder (3) is fitted outside the inner tower (4). The outer cylinder (3) is rotatably connected to the inner tower (4) around a rotation axis.

3. The thrust measurement system according to claim 1, characterized in that, The wind pressure sensor array (9) has the following predetermined matrix form: the number of layers of wind pressure sensors distributed along the height direction of the outer cylinder (3) is m, and the number of sensors distributed along the circumferential direction at the same height direction of the outer cylinder (3) is p, where p=1 or p>1; when p=1, one wind pressure sensor is arranged circumferentially at the same height of the outer cylinder (3), and when p>1, multiple wind pressure sensors are arranged circumferentially at the same height.

4. The thrust measurement system according to claim 3, characterized in that, m≥5, p≥36.

5. The thrust measurement system according to claim 1, characterized in that, The wind pressure sensor is embedded in the outer surface of the outer cylinder (3), and the probe of the wind pressure sensor faces away from the inner tower (4) of the vortex sail. The probe should be flush with the outer surface of the outer cylinder (3).

6. The thrust measurement system according to claim 1, characterized in that, The position synchronization sensor is a photoelectric switch assembly or an incremental encoder. The photoelectric switch assembly includes a photoelectric switch (10) and a reflective marker (11). The photoelectric switch (10) is set on the inner tower (4), and the reflective marker (11) is set on the inner wall of the outer cylinder (3). The probe of the photoelectric switch (10) faces the reflective marker (11).

7. The thrust measurement system according to claim 1, characterized in that, The signal transmission unit is connected to the sensing unit and the data acquisition and processing unit (1) respectively via transmission cable (12), and multiple wind pressure sensors are also connected to the transmission cable (12) respectively.

8. The thrust measurement system according to claim 1, characterized in that, The inner wall of the outer cylinder (3) is connected to the tapered plate (14), and the upper bearing assembly (6) is driven to the tapered plate (14). The signal transmission unit includes a transmission cable (12), a wind pressure junction box (13), and a slip ring (15). The wind pressure junction box (13) is located at the center of the tapered plate (14) and is used to centrally connect the transmission cables (12) of each wind pressure sensor, and then connect them to the slip ring (15) after they are combined into a single transmission cable. The slip ring (15) is located on the main shaft (16) of the upper bearing assembly (6). The slip ring (15) is used to realize the signal and power transmission of the wind pressure sensor array (9) and the data acquisition and processing unit (1).

9. A method for measuring the thrust of a rotary sail based on wind pressure monitoring, characterized in that, The measurement method employs the thrust measurement system according to any one of claims 1 to 8, and the measurement method includes the following steps: S1. At the same time, the environmental monitoring sensor (8), the wind pressure sensor array (9) and the position synchronization sensor monitor in real time, start the acquisition of signals, and transmit them to the data acquisition and processing unit (1). S2. Determine if p=1 is satisfied. If so, use the time integration algorithm. Among them, F t The thrust on the rotating cylinder; m is the number of layers of the wind pressure sensor array (9) distributed along the height direction of the outer cylinder (3); i is the index of the height layer where the wind pressure sensor is located; n is the number of sampling points in one circle; j is the circumferential angle index where the sampling point is located; P i，j Let θ be the pressure value at the i-th height layer and the j-th sampling point; j Δθ is the angle of the j-th sampling point; Δθ is the angle between two adjacent sampling points of the same wind pressure sensor; Δh i Let be the equivalent height represented by the i-th height layer; Determine if p > 1 is satisfied; if so, use the space integration algorithm. Among them, F t The thrust on the rotating cylinder; m is the number of layers of the wind pressure sensor array (9) distributed along the height direction of the outer cylinder (3); i is the height layer index of the wind pressure sensor; p is the number of wind pressure sensors installed in the same circumference; k is the circumferential position index of the wind pressure sensor; P i，k θi represents the pressure value at the k-th wind pressure sensor at the i-th height level; θk represents the angle of the k-th wind pressure sensor; Δθ' represents the angle between two adjacent sampling points of the same wind pressure sensor; Δhi represents the equivalent height represented by the i-th height level. S3. The monitored data is stored in the data storage and display unit (2), and the environmental conditions measured at each time and the calculated thrust, drag and resultant force are displayed in the data storage and display unit (2).

10. The measurement method according to claim 9, characterized in that, When p=1, When p > 1 Among them, F d As resistance, F r For the sake of combined efforts.

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