Wind power boosting rotor surface thrust measuring method and system

Abstract

The invention discloses a method and system for measuring thrust of a wind power boosting rotor, and the method employs a pressure sensor to measure the dynamic pressure of the surface of the rotor, and directly reflects the Magnus effect. Meanwhile, the high-speed wireless communication technology is used for collecting and transmitting data, vibration influence is avoided, the signal noise is low, and the measurement precision is high. Compared with a traditional pressure measuring device, the pressure sensor is directly installed on the surface of the rotor, the pressure does not need to be conducted to the pressure sensing unit through an air pipe, and the problems of pressure loss, pipeline blockage and the like are avoided. Pressure measurement points are arrayed on the surface of the rotor, pressure scanning is conducted in the circumferential direction, and pressure distribution on the surface of the whole rotor is fed back. Finally, wiring is conducted around the main shaft, parts are integrated on the rotating main shaft, and compared with a complex cable data transmission mode, wireless data collection and transmission under the rotating working condition are achieved; a conductive slip ring does not need to be added to the main shaft, the influence of the rotation state is avoided, and the cable winding problem under the rotation working condition is avoided.

Description

Technical Field

[0001] This invention relates to the field of pressure measurement in instruments and meters. Specifically, it measures the pressure distribution on the outer surface of a rotating cylinder wall using a pressure scanning method, thereby obtaining the wind-driven rotor thrust generated by the Magnus effect. Background Technology

[0002] Wind-powered propulsion rotors (hereinafter referred to as rotors) are one of the important technical means to achieve EEDI Phase III standards for large ships. Application data shows that for bulk carriers and large oil tankers, the energy-saving effect of installing rotors can reach 5% to 10%. The working principle of the rotor is based on the Magnus effect. A rotating cylinder subjected to an incoming flow will experience a lateral force perpendicular to the direction of the flow. During navigation, the resultant force generated by the lateral force and the wind force will directly act on the ship itself, which will directly affect the ship's course and energy consumption. Therefore, it is necessary to measure the surface pressure of the rotor to obtain the lateral force generated by the Magnus effect, and thus determine the magnitude of the resultant force acting on the rotor.

[0003] There are two main existing methods: one is to indirectly measure the thrust by measuring the base deformation using strain gauges; the other is to measure the surface pressure using a pressure valve. However, these methods still have the following shortcomings:

[0004] (1) Complex layout of the measurement system: Due to the large size of the rotor structure and the need to perform measurements while rotating, the arrangement of the pressure taps and sensors is relatively complex. Existing pressure valves rely on flexible pressure taps and data cables, which are prone to blockage, large pressure loss, and cable entanglement while rotating.

[0005] (2) Insufficient measurement accuracy: Strain gauges and pressure valves are susceptible to vibration interference, and the rotating slip ring used for signal transmission between rotating and fixed parts has electrical signal noise, which introduces a large amount of noise signal into the original signal, making data post-processing difficult and causing a large measurement error. Summary of the Invention

[0006] In view of the shortcomings of the existing technology, the purpose of this invention is to propose a method and system for measuring the thrust of a wind-powered booster rotor, so as to realize the measurement of the magnitude of the lateral force generated on the rotor surface by the Magnus effect and the magnitude of the total resultant force acting on the rotor itself.

[0007] The rotor thrust refers to the resultant force acting on the entire rotor, which powers the ship's movement; while the surface pressure is the pressure measured at a specific point on the rotor's outer surface. This invention calculates the resultant force acting on the rotor, i.e., the rotor thrust, by directly measuring the surface pressure.

[0008] To achieve the above objectives, in one aspect, the present invention provides a wind-powered booster rotor thrust measurement system, comprising:

[0009] The servo motor is fixedly connected to the rotating spindle via a coupling.

[0010] The PLC is used to send control commands to the servo to drive the rotor to rotate.

[0011] The end cap is fixedly connected to the rotor in the circumferential direction and to the rotating main shaft in the vertical direction;

[0012] The rotor surface is arrayed with n pressure sensors along the central axis, which are used to measure the dynamic pressure on the outer surface of the rotor in the circumferential direction according to the Magnus effect.

[0013] A proximity switch, mounted on the side of the end cover with its sensing side facing outwards from the rotor, is used to mark the starting position in the circumferential direction.

[0014] Furthermore, the pressure sensor is located inside pressure measuring holes distributed on the outer cylindrical surface of the rotor, and its pressure measuring end is tangent to the outer cylindrical surface of the rotor.

[0015] Furthermore, the rotating spindle is designed with multiple through holes along the axial direction for mounting components that rotate with it, including: a lithium battery, a data acquisition card, and a switch conversion module.

[0016] Furthermore, the high-frequency proximity switch operates as follows: the trigger switch signal is amplified into a standard analog signal by the switch quantity conversion module and then transmitted to the acquisition card via a cable.

[0017] Furthermore, the acquisition card is used to simultaneously acquire proximity switch signals and pressure signals, and wirelessly transmit the pressure data per revolution, including start and end position information, to a computer.

[0018] On the other hand, the present invention provides a method for measuring the thrust of a wind-powered booster rotor, applied to the above-mentioned system, comprising the following steps:

[0019] Step 1: The system is running, and the wireless data acquisition card simultaneously collects pressure and proximity switch data and sends them to the computer;

[0020] Step 2: Mark the starting point of each revolution with the proximity switch and obtain the pressure data per revolution;

[0021] Step 3: Calculate the radian corresponding to each pressure data point, and distribute the pressure data for each revolution evenly along the circumference from the starting point at intervals of the radian.

[0022] Step 4: Calculate the force at each measurement point based on the pressure distribution data in the n circumferential directions obtained by the pressure sensor;

[0023] Step 5: Decompose the force at each measuring point along the axial direction, and superimpose the component forces at all measuring points to obtain the rotor thrust.

[0024] Furthermore, step 2 specifically includes:

[0025] When the proximity switch is triggered, the voltage rises from a low level to a high level. The generated analog signal is output as a standard voltage signal by the digital signal conversion module. The rising edge of this signal is taken as the starting point for each rotation of the rotor. The pressure data corresponding to two consecutive rising edges is extracted to obtain the pressure data per revolution.

[0026] Furthermore, step 4 specifically includes:

[0027] Based on the pressure distribution data in n circumferential directions obtained by the pressure sensor, the pressure data distributed along the axial and radial directions on the outer surface of the rotor are obtained;

[0028] Calculate the effective area corresponding to each measured pressure data point based on the rotor's outer radius and axial length.

[0029] Based on the area of ​​action, the force at each measurement point is further calculated.

[0030] Furthermore, step 5 includes:

[0031] A fixed Cartesian coordinate system is established in the projection plane of the rotor along the axial direction, and the force at each measurement point is decomposed into components in the x-axis and y-axis directions;

[0032] By superimposing the force components in the two directions at all measurement points, the resultant force vector acting on the rotor is calculated to obtain the rotor thrust.

[0033] Furthermore, the method also includes:

[0034] Step 6: Place the system in a controlled test environment, including ocean navigation and ocean rain environment, and capture rotor thrust data in real time for specific working conditions.

[0035] Compared with the prior art, the present invention has the following beneficial effects:

[0036] (1) This invention uses a miniature high-frequency dynamic pressure sensor to measure the dynamic pressure on the rotor surface, directly reflecting the Magnus effect. At the same time, it uses high-speed wireless communication technology to collect and transmit data, which is unaffected by vibration, has low signal noise, and high measurement accuracy.

[0037] (2) Compared with traditional pressure scanning valves (pressure measuring devices), the present invention directly installs the pressure sensor on the rotor surface, without the need to use air pipes to transmit pressure to the pressure sensing unit, resulting in no pressure loss, enabling high-frequency measurement, and allowing normal operation in marine rainwater environments without problems such as pipe blockage.

[0038] (3) The present invention arrays pressure measurement points on the rotor surface, scans the pressure along the circumferential direction, and interpolates and fits along the axial direction to provide feedback on the pressure distribution of the entire rotor surface.

[0039] (4) The present invention uses wiring around the spindle. By integrating components such as high-speed wireless acquisition card on the rotating spindle, it realizes wireless data acquisition and transmission under rotating conditions compared to complex cable data transmission methods. Moreover, it does not require the addition of conductive slip rings to the spindle, is not affected by the rotation state, and avoids the problem of cable entanglement under rotating conditions. Attached Figure Description

[0040] Figure 1 This is a schematic diagram of a wind-powered booster rotor thrust measurement system according to an embodiment of this application;

[0041] Figure 2 This is a diagram showing the circumferential distribution of the measured pressure in an embodiment of this application.

[0042] Figure 3 This is a schematic diagram of the area of ​​the pressure measurement point in an embodiment of this application;

[0043] Figure 4 This is a schematic diagram of the force decomposition at the measurement point in an embodiment of this application;

[0044] Figure 5 This is a schematic diagram of the resultant force vector at the measurement point in an embodiment of this application. Detailed Implementation

[0045] In the description of this invention, it should be noted that, 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 or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0046] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0047] like Figure 1As shown in the figure, this application provides a wind-powered rotor thrust measurement system, including: a servo motor 1, a coupling 2, a lithium battery 3, a rotating spindle 4, a miniature high-frequency dynamic pressure sensor 5, a high-speed wireless acquisition card 6, a switch conversion module 7, a rotor 8, an end cover 9, a servo 10, a computer 11, a high-frequency proximity switch 12, and a programmable logic controller (PLC) 13.

[0048] The servo motor 1 is fixedly connected to the rotating spindle 4 via a coupling 2.

[0049] The programmable logic controller 13 is used to send control commands to the servo 10, so that the servo 10 drives the servo motor 1 and the rotating spindle to perform rotational motion at a set speed.

[0050] The rotor 8 and the end cover 9 are fixed and connected in the circumferential direction by screws.

[0051] The end cover 9 and the rotating spindle 4 are connected in the vertical direction by a key and a keyway. Therefore, the rotational motion of the servo motor 1 is transmitted to the rotor 8 in sequence through the coupling 2, the rotating spindle 4, and the end cover 9 to realize the rotational motion of the rotor 8.

[0052] Furthermore, the rotating spindle 4 is designed with multiple through holes along its axial direction for mounting components that rotate with it, including: a lithium battery 3, a high-speed wireless acquisition card 6, and a switch conversion module 7. The lithium battery 3 powers the high-speed wireless acquisition card 6, the switch conversion module 7, the miniature high-frequency dynamic pressure sensor 5, and the high-frequency proximity switch 12.

[0053] Furthermore, pressure measurement holes are distributed on the outer cylindrical surface of the rotor 8. The miniature high-frequency dynamic pressure sensor 5 is installed in each pressure measurement hole, with its pressure measurement end tangent to the outer cylindrical surface of the rotor 8. During the rotation of the rotor 8, its outer cylindrical surface comes into contact with the air. At the boundary, the relative velocity between the air and the outer cylindrical surface is 0, which causes a change in the airflow velocity near the cylindrical surface and forms a dynamic pressure distribution, i.e., the Magnus effect. The miniature high-frequency dynamic pressure sensor 5 rotates with the rotor 8, measuring the dynamic pressure on the outer cylindrical surface along the circumferential direction. The measured pressure signal is transmitted to the high-speed wireless acquisition card 6 via a cable.

[0054] A high-frequency proximity switch 12 is mounted on the side of the end cover 9, with its sensing side facing the outside of the rotor. It is used to mark the starting position in the circumferential direction; that is, when the rotor rotates, the high-frequency proximity switch 12 is triggered once when it passes the 0° position on the circumference (the set starting position). The switching signal triggered by the high-frequency proximity switch 12 is amplified into a standard analog signal by the switch quantity conversion module 7, and then transmitted to the high-speed wireless acquisition card 6 via cable. The high-speed wireless acquisition card 6 simultaneously acquires the proximity switch signal and the pressure signal, wirelessly transmitting the pressure data per revolution, including the starting and ending position information, to the computer 11. The proximity switch signal is used to mark and separate the pressure data obtained from each revolution scan. During the test, the pressure distribution on the outer surface of the rotor 8 can be obtained by arranging n miniature high-frequency dynamic pressure sensors 5 axially along the surface of the rotor 8.

[0055] After receiving the pressure data from the outer surface of the rotor 8, the computer 11 converts the pressure distribution on the rotor surface into rotor thrust through a post-processing algorithm.

[0056] This application also provides a method for measuring the thrust of a wind-powered booster rotor, applied to the above-mentioned system, including the following steps:

[0057] Step 1: Collect pressure data:

[0058] The two channels of the wireless acquisition card simultaneously acquire pressure and proximity switch data at a sampling frequency f and send them to the computer.

[0059] Step 2: Obtain pressure data per revolution:

[0060] When the high-frequency proximity switch is triggered, the voltage rises from a low level to a high level. This analog signal is output as a standard 0~5V voltage signal by the switch conversion module. The rising edge of this signal is taken as the starting point of each rotation of the rotor. The pressure data corresponding to two consecutive rising edges is extracted to obtain the surface pressure distribution after one scan.

[0061] Step 3: Distribute the pressure circumferentially:

[0062] Set the rotor speed to N r / s and determine each pressure data point P. ij By determining the instantaneous position of the rotor rotation, the corresponding radian value for each pressure data point can be obtained. (1)

[0063] The pressure data from one scan are uniformly distributed along the circumference starting from the starting point 0° with intervals of radians Δθ. The resulting circumferential distribution map of the measured pressure is shown below. Figure 2 As shown.

[0064] Step 4: Calculate the force at each measurement point:

[0065] Based on the pressure distribution data in n circumferential directions obtained from n miniature high-frequency dynamic pressure sensors, the pressure data distributed along the axial and radial directions on the outer surface of the rotor are obtained.

[0066] like Figure 3 As shown, given that the outer radius of the rotor is r and the axial length of the rotor is L, the circumferential length Δx, the axial length Δy, and the area Δs corresponding to each measured pressure data point are respectively:

[0067] (2)

[0068] (3)

[0069] (4)

[0070] Assuming the pressure is uniformly distributed on the outer surface of the rotor at each pressure measurement point, the pressure P perpendicular to the rotor axis at each measurement point can be obtained. ij This allows us to obtain the force (i.e., thrust) at each measurement point:

[0071] (5)

[0072] Wherein, the subscript ij represents the i-th measurement point along the rotor circumference and the j-th measurement point along the rotor axis.

[0073] Step 5: Calculate the resultant force based on the circumferential pressure distribution:

[0074] like Figure 4 As shown, a fixed Cartesian coordinate system is established in the projection plane of the rotor along the axial direction, with the axis projection as the origin, the 0° and 180° directions on the circumference as the x-axis, and the 90° and 270° directions as the y-axis; the force F applied at each measurement point is... ij It can be decomposed into two components, Fx, in the x-axis and y-axis directions. ij and Fy ij ,but:

[0075] (6)

[0076] (7)

[0077] in, This indicates the radian value corresponding to the measurement point.

[0078] like Figure 5 As shown, the two component forces at all measurement points are superimposed to calculate the total component force on the rotor along the x-axis and y-axis. , and resultant force vector The rotor thrust is obtained. The calculation formula is:

[0079]

[0080]

[0081]

[0082] Step 6: Place the system in a controlled test environment, including ocean navigation and ocean rain environment, and capture rotor thrust data in real time for specific working conditions.

[0083] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. For those skilled in the art, other variations or modifications can be made based on the above description. It is impossible to exhaustively list all the implementation methods here. All obvious variations or modifications derived from the technical solutions of the present invention are still within the protection scope of the present invention.

Claims

1. A wind assisted propeller thrust measurement system characterized by, The application relates to a servo motor system for measuring the rotor thrust force, comprising the following parts: a servo motor (1) fixedly connected with a rotating main shaft (4) through a coupling (2); a PLC (13) for sending control commands to the servo motor (10) to drive the rotor to rotate; an end cover (9) fixedly connected with the rotor (8) in the circumferential direction and fixedly connected with the rotating main shaft (4) in the vertical direction; The rotor (8) surface is arrayed with n a pressure sensor (5) for measuring the dynamic pressure of the rotor outer surface in the circumferential direction according to the Magnus effect. a proximity switch (12) installed on the side of the end cover (9) and having an inductive side facing the outside of the rotor (8) and used for marking the starting position in the circumferential direction.

2. The system of claim 1, wherein, The pressure sensor is located in a pressure measuring hole distributed on the outer cylindrical surface of the rotor (8) and has a pressure measuring end tangent to the outer cylindrical surface of the rotor (8).

3. The system of claim 1 or 2, wherein, The rotating main shaft (4) is designed with multiple through holes in the axial direction for mounting parts rotating with the rotating main shaft (4), including a lithium battery (3), a collection card (6) and a switching value conversion module (7).

4. The system of claim 3, wherein, The working mode of the high-frequency proximity switch (12) is that, after a trigger switch signal is amplified into a standard analog signal by the switching value conversion module (7), the signal is transmitted to the collection card (6) through a cable.

5. The system of claim 4, wherein, The collection card (6) is used for synchronously collecting proximity switch signals and pressure signals and wirelessly transmitting per-rotation pressure data containing starting and ending position information to a computer (11).

6. A wind assisted thruster thrust measurement method applied to the system of any one of claims 1-5, characterized by, The application further comprises the following steps: Step 1: the system is operated, and the wireless collection card simultaneously collects pressure and proximity switch data and sends the data to the computer; Step 2: the proximity switch marks the starting point of each rotation to obtain per-rotation pressure data; Step 3: the radian corresponding to each pressure data is calculated, and the per-rotation pressure data is evenly distributed along the circumferential direction at intervals of the radian from the starting point; Step 4: Calculate the force of each measuring point according to the pressure distribution data of the circumferential direction obtained by the pressure sensor. n Step 4: Calculate the force of each measuring point according to the pressure distribution data of the circumferential direction obtained by the pressure sensor. Step 5: the force of each measuring point is decomposed in the axial direction, and the component forces of all the measuring points are superposed to obtain the rotor thrust force.

7. The method of claim 6, wherein, The step 2 is specifically as follows: When the proximity switch is triggered, the voltage rises from a low level to a high level, and the generated analog signal is output as a standard voltage signal through the switching value conversion module; the rising edge of the signal is taken as the starting point of each rotation of the rotor; the pressure data corresponding to the signals between two continuous rising edges is intercepted to obtain the per-rotation pressure data.

8. The method of claim 6, wherein, The step 4 is specifically as follows: According to the pressure sensor acquired n The circumferential pressure distribution data, the pressure data distributed along the axial and radial directions on the outer cylindrical surface of the rotor is obtained. the acting area corresponding to each measuring pressure data point is calculated according to the outer radius of the rotor and the axial length of the rotor; the force of each measuring point is further calculated according to the acting area.

9. The method according to claim 6, 7 or 8, characterized in that, The step 5 comprises the following steps: A fixed Cartesian coordinate system is established in the projection plane of the rotor along the axial direction, and the force of each measuring point is decomposed into x the axial direction and y the radial direction of the shaft the resultant force vector of the rotor is calculated by superposing the component forces of all the measuring points in the two directions, and the rotor thrust force is obtained.

10. The method of claim 9, wherein, The application further comprises the following step: Step 6: the system is placed in a controllable test environment, including marine navigation and marine rainwater environment, and the rotor thrust force data is captured in real time for specific working conditions.

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