Aerodynamic force measuring device and method suitable for spinning type air-borne seeds and aircrafts

Abstract

The invention discloses an aerodynamic force measuring device and method suitable for spinning type air-borne seeds and aircrafts, and belongs to the field of aerodynamics. The device comprises a miniature vertical wind tunnel test device, a measuring platform and a sensing and collecting system, the measuring platform comprises an elliptical frame and a test piece support, magnets are arranged at the upper vertex and the lower vertex of the frame respectively, and the test piece support is located in a magnetic field and comprises a transverse rotor and a longitudinal rotor. The inclination angle between the test piece and the horizontal plane can be adjusted by adjusting the connection angle between the transverse rotor and the longitudinal rotor. The device and the method can be applied to aerodynamic characteristic test research of spinning air-borne plant seeds and bionic micro aircrafts thereof, aerodynamic force generated by the spinning air-borne seeds is measured through a wind tunnel test, a flight mechanism in the spinning process of the air-borne seeds is excavated, a theoretical basis is provided for application of the device in the field of unpowered bionic aircrafts, and the device and the method have wide application prospects. Therefore, the invention and development of a novel low-energy-consumption and power-free bionic micro aircraft are promoted.

Description

Technical Field

[0001] The present invention belongs to the field of aerodynamics, and in particular relates to an aerodynamic force measurement device and method suitable for spinning wind-borne seeds and aircraft. Background Art

[0002] Plants have a variety of dispersal methods, among which wind-borne seeds refer to those that travel long distances through natural wind. Based on their flight mode, wind-borne seeds are primarily divided into two categories: slow-descent seeds that adopt a parachute-like pattern, floating with the wind, such as dandelion seeds, poplar seeds, and willow seeds; and self-spinning seeds that utilize a rotor-like pattern, achieving autonomous and stable rotation under the influence of the wind, such as maple seeds, maple poplar seeds, and three-star fruit seeds. Wind-borne seeds have evolved through thousands of years of natural selection and selection, resulting in advanced flight capabilities. Some wind-borne seeds can travel tens or even hundreds of kilometers without consuming their own energy. In recent years, the development of wind-borne seed-inspired micro-aircraft has reached an international forefront. The ultra-low-energy passive flight mode of wind-borne seeds has applications not only in passive aircraft, but also in rotorcraft.

[0003] However, our understanding of the flight mechanism of spinning wind-borne seeds is limited and unclear. Wind tunnel testing of spinning wind-borne seeds is an important component of aerodynamic research. However, due to the small size of the seeds, the aerodynamic forces are also extremely small, and the passive spinning motion of the seeds must be established. Current wind tunnel testing equipment is unable to meet the requirements for measuring the aerodynamic forces of spinning wind-borne seeds. Therefore, a new aerodynamic measurement device and method suitable for spinning wind-borne seeds and aircraft is urgently needed. Summary of the Invention

[0004] The purpose of the present invention is to overcome the defects in the prior art and provide an aerodynamic measurement device and method suitable for spinning wind-borne seeds and aircraft, thereby providing an experimental basis for the study of their aerodynamic characteristics.

[0005] The specific technical solutions adopted in the present invention are as follows:

[0006] In a first aspect, the present invention provides an aerodynamic measurement device suitable for use with spinning wind-borne seeds and aircraft, comprising a miniature vertical wind tunnel test device and a measurement platform located above the device where the airflow is stable;

[0007] The measuring platform includes an elliptical frame and a test piece holder; the upper and lower vertices of the frame are respectively provided with an upper magnet and a lower magnet that can form a magnetic field on a vertical axis; the test piece holder is located in the magnetic field, and includes a transverse rotor and a longitudinal rotor; vertical magnetic pins are coaxially provided on the outer sides of the upper and lower ends of the longitudinal rotor, the pin at the lower end is in contact with the lower magnet, and a gap is left between the pin at the upper end and the upper magnet; the longitudinal rotor can rotate and spin along the vertical axis where the pin is located under the action of airflow; the transverse rotor is detachably fixed to the inside of the longitudinal rotor for carrying the test piece; the inclination angle of the test piece with the horizontal plane can be adjusted by adjusting the connection angle between the transverse rotor and the longitudinal rotor; the top of the measuring platform is connected to a sensing and acquisition system.

[0008] Preferably, the micro vertical wind tunnel test device includes a wind speed control device, a DC fan, a honeycomb and a cave body, and a DC fan and a honeycomb are installed in the cave body from bottom to top, which can completely cover the cross-section at the location; the DC fan is externally connected to a wind speed control device that can steplessly adjust the wind speed, and the honeycomb is used to improve the airflow uniformity in the wind tunnel test section and reduce the airflow deflection angle and turbulence.

[0009] Preferably, the wind speed control device can provide a maximum wind speed of 20 m / s and a minimum resolution of 0.1 m / s.

[0010] Preferably, the transverse rotor and the longitudinal rotor are connected via threads.

[0011] Preferably, the ejector pin is made of metal, and both the transverse rotor and the longitudinal rotor are frame structures made of resin.

[0012] Preferably, the sensing and acquisition system includes a high-precision load sensor, a test data acquisition module and an industrial computer; the high-precision load sensor is connected to the top of the measurement platform and is connected to the industrial computer through the test data acquisition module to read the load signal.

[0013] Preferably, the high-precision load sensor is a strain gauge sensor, model S100 (0.2N) LoadCell, with a range of 0.2N, a maximum safe load of 0.3N, a 4-wire full bridge configuration, a rated resistance of 2.5kΩ, and a rated output of 1.1mV / V.

[0014] Preferably, the test data acquisition module is of model NI-9237, which has 4 analog input channels, an analog input voltage range of -25mV / V to 25mV / V, and a bridge configuration of 1 / 4 bridge.

[0015] Preferably, the upper magnet and the lower magnet are circular structures with a diameter of 6 mm, a thickness of 1 mm, and a tolerance range of ±0.05 mm.

[0016] In a second aspect, the present invention provides a measurement method using the aerodynamic force measurement device for spinning wind-borne seeds and aircraft according to any one of the first aspects, as follows:

[0017] The spin-like wind-borne seed to be measured is used as a test piece and fixed to the transverse rotor. The transverse rotor is then fixed inside the longitudinal rotor at the required inclination angle. The ejector pin at the lower end of the longitudinal rotor is placed in contact with the lower magnet, with a gap left between the ejector pin at the upper end and the upper magnet, so that the entire test piece holder is located within the magnetic field formed by the upper and lower magnets.

[0018] Fix the measurement platform at a stable airflow location above the micro vertical wind tunnel test device, connect the top of the measurement platform to a high-precision load sensor, and connect the high-precision load sensor to the industrial computer through a test data acquisition module;

[0019] The speed of the DC fan is adjusted by the wind speed control device so that the wind tunnel test section of the micro vertical wind tunnel test device can obtain the wind speed required for the measurement test;

[0020] During the measurement process, the spin state of the test piece is observed and the simulated load signal is read on the industrial computer to complete parameter processing and analysis including lift and rotation rate.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] This invention uses typical spinning, wind-blown seeds (e.g., maple seeds) as the measurement object to illustrate the principles of the measurement device. This aerodynamic force measurement device can be applied to experimental research on the aerodynamic characteristics of spinning, wind-blown plant seeds and bionic micro-aircraft (MAAVs) inspired by them. This supports the design of bionic MAAVs that mimic wind-blown seeds and promotes the invention and development of new low-energy / unpowered bionic MAAVs. The invention aims to measure the aerodynamic forces generated by seeds through wind tunnel testing, explore the flight mechanisms during seed spinning, and provide a theoretical basis for their application in the field of unpowered bionic MAAVs. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 Schematic diagram of the overall structure of the aerodynamic force measuring device of the present invention;

[0024] Figure 2 It is a schematic diagram of an elliptical frame structure;

[0025] Figure 3 Schematic diagram of the test piece bracket structure;

[0026] Figure 4 Schematic diagram of the installation of maple seeds (test pieces) on the measurement platform;

[0027] Figure 5 is the original load signal diagram;

[0028] Figure 6 is the load signal diagram after low-pass filtering;

[0029] Figure 7 This is the spectrum diagram of the original payload signal after FFT;

[0030] In the figure: wind speed control device 1, DC fan 2, honeycomb 3, hole 4, measuring platform 5, upper magnet 61, lower magnet 62, ejector pin 71, test piece 72, transverse rotor 73, longitudinal rotor 74, high-precision load sensor 8, test data acquisition module 9, industrial computer 10. DETAILED DESCRIPTION

[0031] The present invention will be further described and illustrated below with reference to the accompanying drawings and specific embodiments. The technical features of each embodiment of the present invention may be combined accordingly without conflict.

[0032] like Figure 1 As shown, the present invention provides an aerodynamic measurement device for spinning wind-borne seeds and aircraft. The device primarily comprises a micro-vertical wind tunnel test apparatus and a measurement platform 5. The micro-vertical wind tunnel test apparatus is used to provide the wind speed required for testing, and the measurement platform 5 is located above the micro-vertical wind tunnel test apparatus, where the airflow is stable. By optimizing the structural design, the present invention significantly reduces the deviation of spinning wind-borne seeds from their natural flight state during wind tunnel testing. This provides a test apparatus and high-precision measurement tools for studying the aerodynamic characteristics of spinning wind-borne seeds, and provides a theoretical basis for promoting the invention and development of new, low-energy, and unpowered biomimetic micro-aircraft.

[0033] As a preferred embodiment of the present invention, a micro-vertical wind tunnel test apparatus primarily comprises a wind speed control device 1, a DC fan 2, a honeycomb 3, and a tunnel body 4. The DC fan 2 is installed in the lower portion of the tunnel body 4, completely covering the cross-section thereof, while the honeycomb 3 is installed in the upper portion, also completely covering the cross-section thereof. The DC fan 2 is externally connected to the wind speed control device 1, which enables stepless wind speed adjustment. The wind speed control device 1 regulates the speed of the DC fan 2, thereby ensuring stable airflow. The honeycomb 3 is used to improve airflow uniformity and reduce airflow deflection and turbulence within the wind tunnel test section.

[0034] Specifically, wind speed control device 1 is a 220V electronic voltage and speed regulator connected to a DC fan via a circuit. It filters and modulates the voltage to obtain a stable initial wind speed over time. It can provide a maximum wind speed of 20 m / s with a minimum resolution of 0.1 m / s. The wind speed control device's control panel features coarse and fine adjustment knobs for adjusting the DC fan's speed.

[0035] In actual use, the micro vertical wind tunnel test device can adopt the structure of a micro vertical wind tunnel test device for low turbulence and ultra-low speed airflow disclosed in Chinese invention patent publication number CN 113029496 A, or it can be simply assembled and connected by a small wind tunnel fan and speed regulator currently available on the market. As long as the obtained micro vertical wind tunnel test device can achieve stepless wind speed adjustment and can improve airflow uniformity, reduce airflow deflection angle and turbulence, etc., it will be sufficient.

[0036] As a preferred embodiment of the present invention, the measuring platform 5 is fixed at a certain distance above the hole 4 to ensure that the test piece 72 is in a position where the airflow is stable.

[0037] The structure and connection method of each component will be described in detail below.

[0038] In the device of the present invention, Figure 4 As shown, the measuring platform 5 mainly includes a frame and a test piece support. Figure 2 As shown, the frame is an elliptical structure, with an upper magnet 61 provided at its upper vertex and a lower magnet 62 provided at its lower vertex. The upper magnet 61 and the lower magnet 62 can form a magnetic field on the vertical axis.

[0039] As a preferred embodiment of the present invention, the upper magnet 61 and the lower magnet 62 are circular in horizontal cross section. The diameter of the magnet is 6 mm, the thickness is 1 mm, and the dimensional tolerance is ±0.05 mm. The vertical straight-line distance between the upper magnet 61 and the lower magnet 62 is 41 mm.

[0040] As a preferred embodiment of the present invention, in the elliptical structure of the frame, either the major axis or the minor axis can be horizontally arranged. The present invention designs the frame into a thin and streamlined elliptical structure, which can reduce the generation of turbulent wakes.

[0041] In the device of the present invention, the test piece holder is located in the magnetic field and is used to fix and adjust the posture of the test piece 72. The test piece holder mainly includes a transverse rotor 73 and a longitudinal rotor 74. Figure 3 As shown. A vertical magnetic pin 71 is installed on the outer side of the upper end of the longitudinal rotor 74, and another vertical magnetic pin 71 is installed on the outer side of the lower end. Both the upper and lower pins 71 are vertically arranged and coaxially arranged. The lower pin 71 contacts the lower magnet 62, while a gap is left between the upper pin 71 and the upper magnet 61. In this embodiment, the gap can be approximately 2 mm to reduce friction during the spin of the test piece holder. Of course, the gap size can be adjusted according to actual conditions while ensuring the desired effect.

[0042] In the apparatus of the present invention, the longitudinal rotor 74 is capable of rotating and spinning along the vertical axis located by the ejector pin 71 under the influence of airflow. The transverse rotor 73 is detachably fixed within the longitudinal rotor 74 and is used to support the test specimen 72. By adjusting the connection angle between the transverse rotor 73 and the longitudinal rotor 74, the inclination angle of the test specimen 72 relative to the horizontal plane can be adjusted. In actual use, the test specimen 72 is attracted between the upper and lower magnets 61 and 62 of the test specimen holder 7 by the upper and lower ejector pins 71. The test specimen 72 then spins about its vertical axis under the influence of the rising airflow in the vertical wind tunnel.

[0043] As a preferred embodiment of the present invention, the transverse rotor 73 and the longitudinal rotor 74 are connected via threads.

[0044] In a preferred embodiment of the present invention, ejector pin 71 can be made of a magnetic metal. Since measurement platform 5 needs to be lightweight and small in cross-section to minimize the impact on the rotor's spin during wind tunnel testing, both transverse rotor 73 and longitudinal rotor 74 can be constructed as a resin frame structure, which can be fabricated via 3D printing.

[0045] In actual use, test specimen 72 is a self-spinning wind-borne seed or a biomimetic micro-aircraft, such as a maple seed (single-winged) or a three-star fruit seed (multi-winged). Each test specimen 72 requires a corresponding test specimen holder 7. For each test configuration, the two sets of balancing screws within the test specimen holder 7 (i.e., the left and right sets of screws connecting the transverse rotor 73 and the longitudinal rotor 74) are moved to balance the mass of the test specimen holder 7 around the rotation axis, thereby reducing lateral vibration during rotation.

[0046] In the device of the present invention, the top of the measuring platform 5 is connected with a sensing and acquisition system, which can collect analog load signals and complete the processing and analysis of data such as lift and rotation rate.

[0047] As a preferred embodiment of the present invention, the sensing and acquisition system mainly includes a high-precision load sensor 8, a test data acquisition module 9, and an industrial computer 10. The high-precision load sensor 8 is connected to the top of the measurement platform 5 and is connected to the industrial computer 10 through the test data acquisition module 9 to read the load signal.

[0048] Specifically, the high-precision load sensor 8 can adopt a high-sensitivity, high-precision S100 thin film strain gauge load sensor, model S100 (0.2N) Load Cell, with a range of 0.2N, a maximum safe load of 0.3N, and an accuracy of 6×10 -6 N. The high-precision load sensor 8 is configured as a 4-wire full bridge with a rated resistance of 2.5kΩ and a rated output of 1.1mV / V. The high-precision load sensor 8 has the advantages of low power consumption, low hysteresis, and good stability.

[0049] Specifically, the test data acquisition module 9 is a NI-9237 model, which has four analog input channels and an analog input voltage range of -25mV / V to 25mV / V. The test data acquisition module 9 has three bridge modes: quarter bridge, full bridge, and half bridge.

[0050] Specifically, the industrial computer 10 installs NI related drivers and connects to the test data acquisition module 9 and the high-precision load sensor 8 to read the simulated load signal. The industrial computer 10 processes and analyzes the read simulated load signal using NI related software.

[0051] In actual use, the sensing and acquisition system obtains the average lift of the test piece by applying a low-pass filter with a cutoff frequency of 2 Hz and taking the average value of the high-precision load sensor signal after 28 seconds of filtering; the maximum error of the lift is expected to be 3×10 -5 N, approximately 2.1% of the lowest lift generated by the specimen during wind tunnel testing. The primary oscillatory component of the high-precision load sensor signal is driven by the periodic lift variations caused by the specimen's rotational motion. A fast Fourier transform (FFT) was applied to the high-precision load sensor signal, and the peaks in the spectrum were identified, representing the specimen's rotation rate. All peaks were single and prominent, indicating that the specimen successfully achieved a stable spin at all wind speeds. The maximum error in the estimated rotation rate was less than 1% of the lowest spin frequency of the specimen during wind tunnel testing.

[0052] The spinning wind-borne seeds in wind tunnel tests may spin slightly differently from their natural free-flight state. In order to minimize the aerodynamic interference caused by the measurement platform, test piece bracket, and other mechanical accessories, and to make the spinning wind-borne seeds as close to their natural spinning state as possible, the present invention adopts several measures: first, the measurement platform is designed to be compact and thin to reduce the impact on the test piece's spinning state during wind tunnel testing; second, the measurement platform is designed to have a thin and streamlined elliptical structure to reduce the generation of turbulent wakes; finally, for each test configuration, the test piece bracket is mass balanced around the rotation axis by moving two sets of balancing screws in the test piece bracket, thereby reducing lateral vibration during rotation.

[0053] The present invention further provides a measurement method using the aerodynamic force measurement device for spinning wind-borne seeds and aircraft, which is specifically as follows:

[0054] The spin-like wind-transmitted seeds to be measured are used as test pieces 72 (such as Figure 4The specimen holder (shown as a maple seed) is secured to a transverse rotor 73, which is then secured within a longitudinal rotor 74 at the desired inclination angle. The lower pin 71 of the longitudinal rotor 74 is placed in contact with the lower magnet 62, with a gap between the upper pin 71 and the upper magnet 61. This positions the entire specimen holder within the magnetic field formed by the upper and lower magnets 61 and 62.

[0055] The measuring platform 5 is fixed at a stable airflow position above the micro vertical wind tunnel test device, and the top of the measuring platform 5 is connected to a high-precision load sensor 8 , which is connected to an industrial computer 10 through a test data acquisition module 9 .

[0056] The speed of DC fan 2 is regulated by wind speed control device 1 to ensure that the wind tunnel test section of the micro-vertical wind tunnel test apparatus achieves the required wind speed for measurement tests. Honeycomb 3 is used to improve airflow uniformity and reduce airflow deflection and turbulence in the wind tunnel test section. Measurement platform 5 is fixed at a certain distance directly above tunnel body 4 to ensure that test piece 72 is positioned in a stable airflow position.

[0057] During the measurement process, the spin state of the test piece 72 is observed, the simulated load signal is read on the industrial computer 10, and parameter processing and analysis including lift and rotation rate are completed by the industrial computer 10.

[0058] Example

[0059] This embodiment utilizes the aerodynamic force measurement device of the present invention suitable for spinning wind-borne seeds and aircraft, and utilizes the above-mentioned measurement method to conduct the above-mentioned test on a maple seed test piece at a wind speed of 5 m / s and collect load signals for about 20 seconds. The device structure and measurement method will not be described in detail.

[0060] The test results of this embodiment are as follows Figure 5 As shown in the figure, it can be seen that the original load signal oscillates strongly, and only the approximate range of the test results can be understood from it, and it is difficult to directly process and analyze it.

[0061] A low-pass filter with a cutoff frequency of 2 Hz is applied to the original load signal. The average variable of the load signal is the lift of the test piece, as shown in Figure 6 As shown in the figure, the load signal after low-pass filtering is clearer, making it easier to process and analyze the corresponding parameters. This indicates that the test piece has transitioned from a static state to a state where it generates lift in a stable airflow.

[0062] The main oscillation component of the load sensor signal is driven by the periodic rise variation caused by the spin motion of the test piece 72. Fast Fourier transform (FFT) is applied to the original load signal, and the left-right symmetrical peak is found in the spectrum, which is the rotation speed of the test piece 72 during the test, as shown in FIG. Figure 7As shown in the figure, it can be seen that the peaks are all single and prominent, indicating that the test piece 72 successfully achieved a stable rotation state during the test.

[0063] The aerodynamic force measurement device of the present invention is suitable for spinning wind-borne seeds and their bionic micro-aircraft, and can be used for experimental research on the aerodynamic characteristics of spinning wind-borne plant seeds and their bionic micro-aircraft. The aerodynamic force generated by spinning wind-borne seeds is measured through wind tunnel tests, and the flight mechanism of wind-borne seeds during the spinning process is explored, providing a theoretical basis for its application in the field of unpowered bionic aircraft, thereby promoting the invention and development of new low-energy and unpowered bionic micro-aircraft.

[0064] The embodiment described above is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Persons skilled in the art may make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, any technical solution obtained by equivalent substitution or equivalent transformation falls within the scope of protection of the present invention.

Claims

1. An aerodynamic measurement device suitable for spinning wind-borne seeds and aircraft, characterized in that: It includes a micro vertical wind tunnel test device, a measurement platform (5) located at a stable airflow position above the micro vertical wind tunnel test device, and a sensing and acquisition system; The measuring platform (5) comprises an elliptical frame and a test piece support; an upper magnet (61) and a lower magnet (62) capable of forming a magnetic field on a vertical axis are respectively arranged at the upper and lower vertices of the frame; the test piece support is located in the magnetic field and comprises a transverse rotor (73) and a longitudinal rotor (74); vertical magnetic thimbles (71) are coaxially arranged on the outer sides of the upper and lower ends of the longitudinal rotor (74), the thimble (71) at the lower end contacts the lower magnet (62), and a gap is left between the thimble (71) at the upper end and the upper magnet (61); the longitudinal rotor (74) can rotate and spin along the vertical axis where the thimble (71) is located under the action of airflow; the transverse rotor (73) is detachably fixed inside the longitudinal rotor (74) and is used to carry the test piece (72); the inclination angle of the test piece (72) and the horizontal plane can be adjusted by adjusting the connection angle between the transverse rotor (73) and the longitudinal rotor (74); the top of the measuring platform (5) is connected to a sensing and acquisition system.

2. The aerodynamic force measurement device for spinning wind-borne seeds and aircraft according to claim 1, characterized in that: The micro vertical wind tunnel test device comprises a wind speed control device (1), a DC fan (2), a honeycomb (3) and a tunnel body (4); the DC fan (2) and the honeycomb (3) are respectively installed in the tunnel body (4) from bottom to top, each capable of completely covering the cross section thereof; the DC fan (2) is externally connected to a wind speed control device (1) capable of steplessly adjusting the wind speed; the honeycomb (3) is used to improve the airflow uniformity and reduce the airflow deflection angle and turbulence in the wind tunnel test section.

3. The aerodynamic force measurement device for spinning wind-borne seeds and aircraft according to claim 2, characterized in that: The wind speed control device (1) can provide a maximum wind speed of 20 m / s and a minimum resolution of 0.1 m / s.

4. The aerodynamic force measurement device for spinning wind-borne seeds and aircraft according to claim 1, characterized in that: The transverse rotor (73) and the longitudinal rotor (74) are connected via threads.

5. The aerodynamic force measurement device for spinning wind-borne seeds and aircraft according to claim 1, characterized in that: The ejector pin (71) is made of metal, and the transverse rotor (73) and the longitudinal rotor (74) are both frame structures made of resin material.

6. The aerodynamic force measurement device for spinning wind-borne seeds and aircraft according to claim 1, characterized in that: The sensing and acquisition system comprises a high-precision load sensor (8), a test data acquisition module (9) and an industrial control computer (10); the high-precision load sensor (8) is connected to the top of the measuring platform (5) and is connected to the industrial control computer (10) through the test data acquisition module (9) to read the load signal.

7. The aerodynamic force measurement device for spinning wind-borne seeds and aircraft according to claim 6, characterized in that: The high-precision load sensor (8) is a strain gauge sensor, model S100 (0.2N) Load Cell, with a range of 0.2N, a maximum safe load of 0.3N, a 4-wire full bridge configuration, a rated resistance of 2.5kΩ, and a rated output of 1.1mV / V.

8. The aerodynamic force measurement device for spinning wind-borne seeds and aircraft according to claim 6, characterized in that: The test data acquisition module (9) is of model NI-9237, has 4 analog input channels, an analog input voltage range of -25mV / V to 25mV / V, and a bridge configuration of 1 / 4 bridge.

9. The aerodynamic force measurement device for spinning wind-borne seeds and aircraft according to claim 1, characterized in that: The upper magnet (61) and the lower magnet (62) are circular structures with a diameter of 6 mm and a thickness of 1 mm, with a tolerance range of ±0.05 mm.

10. A method for measuring aerodynamic forces using the aerodynamic force measuring device for spinning wind-borne seeds and aircraft according to any one of claims 1 to 9, characterized in that: The details are as follows: The spin-like wind-borne seeds to be measured are used as test pieces (72) and fixed on the transverse rotor (73), and then the transverse rotor (73) is fixed inside the longitudinal rotor (74) at a desired inclination angle; the ejector pin (71) at the lower end of the longitudinal rotor (74) is placed in contact with the lower end magnet (62), and a gap is left between the ejector pin (71) at the upper end and the upper end magnet (61), so that the entire test piece bracket is located in the magnetic field formed by the upper end magnet (61) and the lower end magnet (62); The measuring platform (5) is fixed at a stable airflow position above the micro vertical wind tunnel test device, the top of the measuring platform (5) is connected to a high-precision load sensor (8), and the high-precision load sensor (8) is connected to an industrial control computer (10) through a test data acquisition module (9); The rotation speed of the DC fan (2) is adjusted by a wind speed control device (1) so that the wind tunnel test section of the micro vertical wind tunnel test device obtains the wind speed required for the measurement test; During the measurement process, the spin state of the test piece (72) is observed, and the simulated load signal is read on the industrial computer (10) to complete parameter processing and analysis including lift and rotation rate.

Images