Wave flow field wave-absorbing sensing device and sensor

Abstract

The application provides a wave flow field absorbing sensor device and sensor, the sensor device comprises an optical fiber and a floating ball, a rigid support rod and an elastic round seat plate connected in sequence from top to bottom, the floating ball, the support rod and the round seat plate form an axial symmetry structure with the support rod as the central axis; the optical fiber surrounds at least one circle with the center of the round seat plate as the center on the round seat plate, and is drawn out from the left and right sides of the center of the round seat plate respectively, the optical fiber on the round seat plate is fixedly connected with the round seat plate; the circumference of the round seat plate is used for fixedly connecting with a marine structure. The device adopts the optical fiber and optical fiber signal to replace electrical elements and electrical signals for sensing, meanwhile, the optical fiber is wired in a circular ring mode to form a symmetrical structure, which can improve the durability, reliability and measurement accuracy of the device in the marine environment, and the axial symmetry structure makes the reaction to the wave action in each direction have consistent sensitivity.

Description

Technical Field

[0001] This invention relates to the field of flow field monitoring equipment technology, and in particular to a wave flow field absorbing sensing device and sensor. Background Technology

[0002] Ocean waves are forms of seawater movement caused by the combined effects of external forces, gravity, and surface tension. In a narrow sense, ocean waves refer to wind waves, swells, and nearshore waves; in a broader sense, they also include large-scale seawater fluctuations caused by factors such as celestial gravity, earthquakes, volcanic eruptions, landslides, air pressure changes, and differences in seawater density, such as tsunamis, storm surges, and internal ocean waves. The energy carried by the undulating and tumbling motion of seawater can be converted into electrical energy through wave energy generation devices. However, it can also cause impact damage to offshore structures. Therefore, ocean wave monitoring is of great significance for guiding marine engineering construction, marine economic development, transportation, fishing and aquaculture, and efficient power generation. Currently, the main method of ocean wave monitoring is through monitoring on ships, buoys, and nearshore island marine stations, with wave sensors being one of the important monitoring devices used.

[0003] Wave sensors can be categorized into six types based on their fundamental physical principles: 1) optical rangefinders; 2) resistance and capacitance wavemeters; 3) pressure wavemeters; 4) acoustic wavemeters; 5) gravity wavemeters; and 6) remote sensing wavemeters. Wave monitoring primarily encompasses multiple dimensions, including sea state, waveform, wave height, wave direction, and period. Currently, the more mature wave sensor products mainly fall into the following categories:

[0004] A wavemeter is a vertical rod inserted into water, primarily used to measure wave height and period. The method is simple and economical. Its main principle is to utilize the changes in resistance, capacitance, and electromagnetic properties of the wavemeter caused by the rise and fall of ocean waves to measure wave height and period.

[0005] An ultrasonic wave meter is a sonar echolocation system placed underwater or on the surface of water. It consists of a transmitting transducer, a receiving transducer, an exciter, and a recording unit. Abnormal reflected signals generated by schools of fish, breaking waves, ships, etc., can affect the wave measurement results.

[0006] Accelerometers primarily measure the acceleration generated by ocean waves impacting floating objects such as buoys. The acceleration sensor can be encapsulated inside the waterproof cavity of the buoy to avoid seawater corrosion. Therefore, it has excellent characteristics such as high sensitivity, signal tracking, and good durability, making it suitable for long-term, fixed-point, real-time ocean wave monitoring.

[0007] Laser wave measurement systems primarily measure wave height by measuring the time difference between laser incidence and reflection to obtain the sea surface reflection signal. The resolution of the wave profile obtained by laser measurement can reach the centimeter level, but the measurement accuracy is easily affected by many factors such as the sea surface reflection characteristics, and related technologies are still being continuously improved.

[0008] Strain gauges and wave direction meters can measure information such as flow velocity, wave direction, and frequency by measuring the impact force of waves on a wave-absorbing structure. For example, by attaching four strain gauges to the surface of a thin-walled circular tube to form a strain measurement bridge, the force applied to a wave-absorbing sphere installed at the top of the tube can be used to sense the direction of the waves, and the stress state of the tube can be used to determine the wave height, period, and wave direction.

[0009] Remote sensing measurements primarily rely on radar and stereo imaging equipment mounted on coastlines, survey vessels, satellites, and aircraft to achieve large-scale panoramic stereoscopic measurements of waves from land, sea, air, and space. This is mainly used for macroscopic scenarios such as weather forecasting and wave energy surveying. However, engineering scenarios involving fluid-structure interaction analysis of marine engineering structures still primarily rely on wave sensors deployed in the field.

[0010] The sensing probes of the various wave sensors based on electrical components mentioned above all contain metallic electrical components and all use cables to transmit electrical signals. However, metallic components and cables have defects such as poor corrosion resistance, susceptibility to electromagnetic interference, and large attenuation of remote measurement signals in marine environments. Therefore, their durability, reliability, and measurement accuracy are severely limited. Summary of the Invention

[0011] The purpose of this invention is to overcome the shortcomings of the prior art and propose a wave flow field absorbing sensing device and sensor to solve the problems of poor durability, low reliability and limited measurement accuracy of existing wave sensor structures based on electrical components in marine environments.

[0012] The present invention provides a wave flow field absorbing sensing device, comprising: an optical fiber and a float, a rigid support rod and an elastic circular base plate connected sequentially from top to bottom, wherein the float, support rod and circular base plate form an axisymmetric structure with the support rod as the central axis;

[0013] The optical fiber is drawn out from the left and right sides of the circular base plate after wrapping around the center of the circular base plate at least once. The optical fibers in each circle are distributed radially at intervals. The optical fibers on the circular base plate are fixedly connected to the circular base plate. The optical fibers forming the circle are all tightly connected to the circular base plate, and the optical fibers that do not form the circle are armored optical fibers.

[0014] The circular base plate is used for fixed connection with marine structures.

[0015] Preferably, the circular base plate includes an elastic circular plate and a base;

[0016] The base is provided with an inner hole with a diameter not greater than that of the elastic circular plate. The elastic circular plate is coaxial with the inner hole. The base and the elastic circular plate are connected by a plurality of bolts evenly arranged along the circumference of the inner hole.

[0017] The optical fiber is wound around the center of the elastic circular plate at least once and then led out from the left and right sides of the center of the plate to the base.

[0018] The base is fixedly connected to the marine structure.

[0019] More preferably, the circular base plate further includes a flange, and the elastic circular plate is located between the base and the flange;

[0020] The flange is evenly provided with a plurality of first bolt holes along its circumference, the elastic circular plate is evenly provided with a plurality of second bolt holes along its circumference, and the base is evenly provided with a plurality of third bolt holes along its inner hole circumference. The first bolt holes, second bolt holes, and third bolt holes are all one-to-one corresponding. Each bolt passes through the one-to-one corresponding first bolt hole, second bolt hole, and third bolt hole in sequence to connect and fix the flange, the elastic circular plate, and the base.

[0021] The base has a first groove and a second groove on both sides of the inner hole center on its upper end face. The optical fiber is introduced into the elastic circular plate through the first groove, and after wrapping around the lower end face of the elastic circular plate at least once, it is led out from the second groove.

[0022] More preferably, the first groove and the second groove are sealed with a corrosion-resistant material;

[0023] A corrosion-resistant sealing ring is provided between the flange and the elastic circular plate.

[0024] Preferably, the optical fibers forming the circle are all tightly bonded to the circular base plate using a corrosion-resistant adhesive.

[0025] Preferably, the float is an axisymmetric streamlined shell.

[0026] Preferably, the float, support rod, and circular seat plate are all made of stainless steel.

[0027] Preferably, the support rod is welded to the float and the circular base plate respectively.

[0028] Another object of the present invention is to provide a wave flow field sensor, including an OFDR distributed fiber optic demodulator and a wave-absorbing sensing module;

[0029] The absorbing wave sensing module is composed of at least one of the above-mentioned wave flow field absorbing wave sensing devices connected in series. The free end of the optical fiber of the wave flow field absorbing wave sensing device at one end is connected to the OFDR distributed optical fiber demodulator, and the free end of the optical fiber of the wave flow field absorbing wave sensing device at the other end is connected to a signal attenuation device.

[0030] Preferably, the signal attenuation device is a signal attenuator.

[0031] As can be seen from the above technical solutions, the present invention has the following advantages:

[0032] The present invention provides a wave flow field absorbing sensing device, which transmits the wave flow field force on the float to the circular base plate through the support rod, causing the circular base plate to undergo elastic deformation. The strain distribution of the circular base plate is measured by an optical fiber tightly connected to the circular base plate in a circular route, and an optical fiber signal is generated. The magnitude and direction of the wave flow field can then be obtained by acquiring and processing the optical fiber signal. This invention utilizes the advantages of optical fibers, such as small size, light weight, corrosion resistance, electromagnetic immunity, and long signal transmission distance. It replaces electrical components and signals with optical fibers and optical fiber signals for sensing. Furthermore, the optical fibers are routed in a circular pattern to form a symmetrical structure, ensuring consistent measurement accuracy in all directions. This avoids the drawbacks of sensing structures based on electrical components and signals in marine environments, such as poor durability, low reliability, and limited measurement accuracy. This improves the device's durability, reliability, and measurement accuracy in marine environments. The axially symmetrical structure formed by the float, support rod, and circular base plate provides consistent sensitivity to wave action in all directions, giving the device omnidirectional wave sensing capability. Moreover, the device has few components, a simple structure and manufacturing process, and low manufacturing and maintenance costs. Attached Figure Description

[0033] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0034] Figure 1 A schematic diagram of the structural principle of a wave flow field absorbing sensor provided in Embodiment 1 of the present invention. Figure 1 ;

[0035] Figure 2 A schematic diagram of the structural principle of a wave flow field absorbing sensor provided in Embodiment 1 of the present invention. Figure 2 ;

[0036] Figure 3A schematic diagram of the structural principle of a wave flow field absorbing sensor provided in Embodiment 1 of the present invention. Figure 3 ;

[0037] Figure 4 This is an exploded structural diagram of a wave flow field absorbing sensor provided in Embodiment 1 of the present invention;

[0038] Figure 5 This is a three-dimensional structural diagram of a wave flow field absorbing sensor provided in Embodiment 1 of the present invention;

[0039] Figure 6 This is a simplified schematic diagram illustrating the structural principle of a wave flow field sensor (single-point type) provided in Embodiment 2 of the present invention;

[0040] Figure 7 This is a simplified schematic diagram illustrating the structural principle of a wave flow field sensor (array type) provided in Embodiment 2 of the present invention;

[0041] The reference numerals in the attached drawings are as follows: 1. Fiber optic cable; 101. Fiber optic cable forming a circle; 102. Fiber optic cable not forming a circle; 2. Float; 3. Support rod; 4. Circular base plate; 5. Elastic circular plate; 6. Base; 7. Inner hole; 8. Flange; 9. First bolt hole; 10. Second bolt hole; 11. Third bolt hole; 12. First groove; 13. Second groove; 14. Countersunk screw; 15. Wave flow field absorbing sensor; 16. Corrosion-resistant adhesive; 17. Flow field; 18. OFDR distributed fiber optic demodulator; 19. Marine structure. Detailed Implementation

[0042] To make the objectives, features, and advantages of this invention more apparent and understandable, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described below are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0043] In the description of this application, it should be noted that the terms "upper", "lower", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0044] Unless otherwise expressly specified and limited, the terms "connection," "fixed," and "set" 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, a direct connection, or an indirect connection through an intermediate medium; or they can refer to a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0045] Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first," "second," or "third" may explicitly or implicitly include one or more of that feature, unless otherwise expressly specified.

[0046] Embodiment 1 of the present invention provides a wave flow field absorbing sensing device for wave monitoring, such as... Figures 1-3 As shown, it includes: an optical fiber 1 and a float 2, a rigid support rod 3, and an elastic circular base plate 4 connected sequentially from top to bottom. The float 2, support rod 3, and circular base plate 4 form an axisymmetric structure with the support rod 3 as the central axis. The float 2 is an axisymmetric streamlined shell, such as a sphere or an ellipsoid. The float 2, support rod 3, and circular base plate 4 are all made of corrosion-resistant materials, preferably stainless steel, to prevent seawater corrosion.

[0047] Optical fiber 1 is laid on the circular base plate 4, with the center of the circular base plate 4 as the center, and then leads out from the left and right sides of the center of the circular base plate 4. The optical fibers in each circle are distributed radially at intervals. The optical fibers 1 on the circular base plate 4 are fixedly connected to the circular base plate 4. The optical fibers 1 on the circular base plate 4 are composed of optical fibers 101 forming the circle and optical fibers 102 not forming the circle. The optical fibers 101 forming the circle are all tightly connected to the circular base plate 4. In order to prevent the optical fibers forming the circle from being pulled and damaged by the waves, the optical fibers 102 not forming the circle are armored optical fibers and are fixedly connected to the circular base plate 4. Preferably, the optical fibers 101 forming the circle are all tightly bonded to the circular base plate 4 with corrosion-resistant adhesive 16. This not only ensures that the optical fibers 101 forming the circle are completely and tightly connected to the circular base plate 4, but also ensures the seawater corrosion resistance of the materials used, thereby ensuring the stability of the structure and the accuracy of the measurement.

[0048] The circular base plate 4 is used for fixed connection with the marine structure 19, and the buoy 2 is used to be subjected to the wave flow field.

[0049] It should be noted that in this embodiment, the optical fiber is preferably a low-cost standard commercial single-mode optical fiber, which can further reduce the cost of this device. The silica material in the optical fiber naturally has corrosion resistance. The rigidity of the rigid support rod 3 refers to the relative rigidity of the support rod 3, which aims to ensure the effectiveness of its force transmission and avoid force loss during the transmission process. The elasticity of the elastic circular base plate 4 refers to the ability of the circular base plate 4 to undergo elastic deformation due to the force received from the support rod 3. The connection method between the circular base plate 4 and the marine structure is preferably a fixing method that allows its circumference to be formed as a simply supported side or a fixed supported side.

[0050] This invention provides a wave flow field absorbing sensing device, such as... Figure 2 As shown, the force of the wave flow field 17 on the float 2 is transmitted to the circular base plate 4 through the support rod 3, so that the circular base plate 4 is subjected to bending and lateral forces at the same time and undergoes elastic deformation. The strain distribution of the circular base plate 4 is measured by the optical fiber tightly connected to the circular base plate 4 in a circular route and an optical fiber signal is formed. Then, the magnitude and direction of the wave flow field can be obtained by acquiring and processing the optical fiber signal. This invention utilizes the advantages of optical fibers, such as small size, light weight, corrosion resistance, electromagnetic immunity, and long signal transmission distance. It replaces electrical components and signals with optical fibers and optical fiber signals for sensing. Furthermore, the optical fibers are routed in a circular pattern to form a symmetrical structure, ensuring consistent measurement accuracy in all directions. This avoids the drawbacks of sensing structures based on electrical components and signals in marine environments, such as poor durability, low reliability, and limited measurement accuracy. This improves the device's durability, reliability, and measurement accuracy in marine environments. In this embodiment, the float 2, support rod 3, and circular base plate 4 are all made of corrosion-resistant materials, further enhancing the device's durability and reliability. The axially symmetrical structure formed by the float 2, support rod 3, and circular base plate 4 provides consistent sensitivity to wave action in all directions, giving the device omnidirectional wave sensing capability. Moreover, this device has few components, a simple structure and manufacturing process, and low manufacturing and maintenance costs.

[0051] To ensure the reliability and stability of the connection between the circular base plate 4 and the marine structure, continuous welding is usually chosen. However, continuous welding often causes deformation of the plate. To avoid this deformation of the circular base plate 4, which would affect the accuracy of the deformation, in a specific embodiment, the circular base plate 4 includes an elastic circular plate 5 and a base 6. The base 6 has an inner hole 7 with a diameter not greater than the diameter of the elastic circular plate 5. The elastic circular plate 5 is coaxial with the inner hole 7. The base 6 and the elastic circular plate 5 are connected by a plurality of bolts evenly arranged along the circumference of the inner hole 7. The optical fiber 1 is wound around the center of the elastic circular plate 5 at least once and then led out of the base 6 from the left and right sides of the center. The base 6 is fixedly connected to the marine structure. Thus, the connection between the base 6 and the marine structure can avoid the above-mentioned situation.

[0052] Furthermore, the circular base plate 4 also includes a flange 8, and an elastic circular plate 5 is located between the base 6 and the flange 8. The flange 8 is evenly provided with a plurality of first bolt holes 9 along its circumference, the elastic circular plate 5 is evenly provided with a plurality of second bolt holes 10 along its circumference, and the base 6 is evenly provided with a plurality of third bolt holes 11 along its inner hole 7. The first bolt holes 9, the second bolt holes 10, and the third bolt holes 11 are all one-to-one correspondences. Each bolt passes through the corresponding first bolt hole 9, second bolt hole 10, and third bolt hole 11 in sequence to connect and fix the flange 8, the elastic circular plate 5, and the base 6. By setting the flange 8 and clamping the elastic circular plate 5 between the flange 8 and the base 6, the circumference of the elastic circular plate 5 is subjected to uniform pressure, which can avoid stress concentration at the bolt holes when the elastic circular plate 5 is directly bolted to the base 6, thereby further ensuring that the elastic deformation generated by the elastic circular plate 5 is real and accurate.

[0053] The base 6 has a first groove 12 and a second groove 13 on both sides of the center of the inner hole 7 on its upper end face. The optical fiber 1 is introduced into the elastic circular plate 5 through the first groove 12, and after wrapping around the lower end face of the elastic circular plate 5 at least once, it is led out from the second groove 13. Preferably, the first groove 12 and the second groove 13 are sealed with a corrosion-resistant material, and a corrosion-resistant sealing ring is provided between the flange 8 and the elastic circular plate 5. In this way, after the base 6 is fixed to the underwater marine structure, not only can the optical fibers in the first groove 12 and the second groove 13 be fixedly connected to the base 6, but the optical fibers wrapped around the lower end face of the elastic circular plate 5 are also kept in a sealed space, so as not to be exposed to seawater and threatened by corrosion, which is beneficial to improving the durability and reliability of the device in this embodiment.

[0054] For example, such as Figures 4-5 As shown, float 2 is a lightweight hollow sphere made of 316L stainless steel with a diameter of 30-50mm; support rod 3 is a solid thin rod made of 316L stainless steel with a diameter of 5-10mm and a length of 300mm; elastic circular plate 5 is a 1.5mm thick 316L stainless steel circular plate with a diameter of 110mm, and eight φ3mm unthreaded circular holes are evenly provided along the center of its circumference, which are the second bolt holes 10; support rod 3 is welded to float 2 and elastic circular plate 5 respectively; flange 8 is made of 316L stainless steel with an inner diameter of 10mm. The flange 8, the elastic circular plate 5, and the base 6 are made of 316 stainless steel. The flange 8, the elastic circular plate 5, and the base 6 are 0mm in diameter, 120mm in outer diameter, and 1cm in height. The elastic circular plate 5 is fixedly supported on the circumference at a diameter of 100mm.

[0055] All types of wave sensors based on electrical components contain metallic electrical components inside their sensing probes and use cables to transmit electrical signals. However, in marine environments, the complex signal lines of these metallic components and cables make it difficult to achieve large-scale array measurements. Typically, they are used for single-point measurements. If applied to large-scale multi-point measurements, a large number of cables must be laid, resulting in complex signal cable structures, high costs, and difficult maintenance in marine environments. Furthermore, the resistance of metallic components and metal wires is temperature-dependent, and measurement accuracy is often affected by temperature changes. To compensate for temperature interference, a temperature compensation mechanism must be used during measurement, usually by setting up a large temperature compensation block, which limits the measurement accuracy.

[0056] To overcome the above-mentioned defects, Embodiment 2 provides a wave flow field sensor, including a fiber optic strain sensor demodulator with millimeter-level spatial resolution and a wave absorption sensing module; the wave absorption sensing module is composed of at least one of the above-mentioned wave flow field absorbing sensing devices 15 connected in series, wherein the free end of the fiber optic cable of one end of the wave flow field absorbing sensing device 15 is connected to the fiber optic strain sensor demodulator, and the free end of the fiber optic cable of the other end of the wave flow field absorbing sensing device 15 is connected to a signal attenuation device.

[0057] It should be noted that signal attenuation processing is required at the end of the optical fiber. The aforementioned signal attenuation device includes, but is not limited to, a signal attenuator, or other measures and devices that can achieve optical fiber signal attenuation. A fiber optic strain sensor demodulator with millimeter-level spatial resolution means that there is a strain measurement point every millimeter on the optical fiber. The free end of the optical fiber of the aforementioned wave flow field absorbing sensor 15 can be connected to the fiber optic strain sensor demodulator by means of fiber optic patch cords or welding to extend the optical fiber, or multiple of the aforementioned wave flow field absorbing sensors can be connected in series to achieve array deployment. In one specific embodiment, the fiber optic strain sensor demodulator is an OFDR distributed fiber optic demodulator 18. The Optical Frequency Domain Reflectometer (OFDR) is a high spatial resolution distributed fiber optic sensor, which is one of the most advanced distributed fiber optic sensing technologies currently available. It uses standard commercial single-mode fiber (160μm outer diameter polyimide coating or 250μm outer diameter acrylate coating) and can achieve a maximum sampling frequency of 200Hz over a 100m fiber length. The highest spatial resolution is 0.65mm, meaning that a strain measurement point can be obtained every 0.65mm on the fiber, and the strain measurement accuracy reaches ±1με.

[0058] Example 2 provides a wave flow field sensor. In the wave flow field absorbing sensing device 15, the optical fiber forming the circle can measure the elastic strain generated by the circular base plate 4 on its circumference, forming an optical fiber signal including temperature and strain signals. The optical fiber signal contains information about the effect of the wave field acting on the float 2. The OFDR distributed optical fiber demodulator 18 first separates the temperature and strain signals through the optical fiber ring temperature / strain decoupling algorithm (the core principle of the algorithm is to demodulate the strain in the tangential direction at various points on the circumference of the optical fiber ring by the OFDR device, and combine it with thermoelastic theory to decouple and obtain the strain field and temperature field near the optical fiber ring area. For the specific algorithm, please refer to the literature "Yang T, Wang X. Decoupling and Simultaneous Measurement of Nonuniform Strain and Temperature Using a SingleDistributed Optical Fiber Ring. Experimental Mechanics, 2022, 62(9):1531-1552". This is the existing technology and will not be elaborated here). Then the strain field distribution is obtained. Since there is a one-to-one correspondence between the optical fiber signal and the wave flow field, the conversion coefficient obtained by experimental calibration can convert the magnitude and direction information of the strain into the magnitude and direction information of the wave flow field vector, thereby achieving the purpose of monitoring waves.

[0059] When the absorbing sensor module includes only one wave flow field absorbing sensor 15, it constitutes a single-point sensor. In use, the OFDR distributed fiber demodulator 18 needs to be set to extract only the measurement fiber signal on the fiber segment forming the circle, and the fiber outside the circle is only used to transmit fiber signals. When the absorbing sensor module includes two or more wave flow field absorbing sensor 15, it constitutes an array sensor. In use, firstly, the OFDR distributed fiber demodulator 18 needs to be set to locate the fiber corresponding to each wave flow field absorbing sensor 15, and the fiber frequency drift of the fiber segment forming the circle needs to be extracted. Then, the signal of each fiber forming the circle is decoupled to obtain the strain field, and finally, it is converted into the corresponding flow field information through calibration.

[0060] The wave flow field sensor provided in this embodiment utilizes an OFDR distributed fiber optic demodulator 18 with a spatial resolution accurate to 0.65 mm. This allows for the acquisition of strain signals from sufficiently densely spaced, uniformly spaced measurement points on the circular optical fibers forming the wave flow field absorbing sensor 15. Abnormal signals at individual measurement points have minimal impact on the overall measurement accuracy, and strain signals from different measurement points can mutually correct each other, thereby enhancing the sensor's error correction capability, ensuring accurate calculation of the deformation state of the elastic circular base plate 4, and improving the sensor's measurement accuracy. By employing a fiber optic loop strain / temperature decoupling algorithm through the OFDR distributed fiber optic demodulator 18, the temperature and strain signals measured by the circular optical fibers can be accurately separated, thus obtaining the strain field distribution. Calibration of the strain field converts the magnitude and direction information of the strain into the magnitude and direction information of the wave flow field vector, eliminating the interference of temperature on strain measurement and ensuring and further improving measurement accuracy. One wave flow field absorbing sensor 15 can be connected to a single optical fiber measurement channel to form such a configuration. Figure 6 The single-point sensor shown can also be connected in series with multiple wave flow field absorbing sensors 15 to form a configuration as shown above. Figure 7 The array-type sensor shown enables array-based measurement. Its simple structure allows for the use of inexpensive commercial single-mode fiber, offering significant advantages in material and construction costs. This effectively addresses the shortcomings of traditional wave sensors based on electrical components, which require temperature compensation mechanisms, resulting in low measurement accuracy and difficulty in achieving large-scale array measurements. Alternatively, this embodiment can be used to form an integrated multi-sensor OFDR with multiple fiber optic measurement channels to achieve a wider range of wave flow field measurements.

[0061] It should be noted that Embodiments 1 and 2 can not only be used for wave flow field sensing, and by experimentally optimizing the shape and size of the float 2, they can also be used to monitor air flow fields or other types of flow fields. In particular, fiber optic sensing is immune to electromagnetic interference, and therefore can be used for measuring current fields in sandstorm flow fields with strong electromagnetic interference and in chemical industrial reactors.

[0062] The above-described embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A wave flow field absorbing sensing device, characterized in that, It includes an optical fiber and a float, a rigid support rod, and an elastic circular base plate connected in sequence. The float, support rod, and circular base plate form an axisymmetric structure with the support rod as the central axis. The circular base plate includes a base, an elastic circular plate, and a flange, wherein the elastic circular plate is located between the base and the flange; The base is provided with an inner hole with a diameter not greater than that of the elastic circular plate. The elastic circular plate is coaxial with the inner hole. The base, the elastic circular plate and the flange are connected by a plurality of bolts evenly arranged along the circumference of the inner hole. The optical fiber is drawn out from the left and right sides of the center of the elastic circular plate after wrapping around the circular base plate at least once. The optical fibers in each circle are distributed radially at intervals. The optical fibers on the circular base plate are fixedly connected to the circular base plate. The optical fibers forming the circles are all tightly connected to the circular base plate, and the optical fibers that do not form the circles are armored optical fibers. The base is fixedly connected to the marine structure.

2. The wave flow field absorbing sensing device according to claim 1, characterized in that: The flange is evenly provided with a plurality of first bolt holes along its circumference, the elastic circular plate is evenly provided with a plurality of second bolt holes along its circumference, and the base is evenly provided with a plurality of third bolt holes along its inner hole circumference. The first bolt holes, second bolt holes, and third bolt holes are all one-to-one corresponding. Each bolt passes through the one-to-one corresponding first bolt hole, second bolt hole, and third bolt hole in sequence to connect and fix the flange, the elastic circular plate, and the base. The base has a first groove and a second groove on both sides of the inner hole center on its upper end face. The optical fiber is introduced into the elastic circular plate through the first groove, and after wrapping around the lower end face of the elastic circular plate at least once, it is led out from the second groove.

3. The wave flow field absorbing sensing device according to claim 2, characterized in that: The first and second grooves are sealed with a corrosion-resistant material; A corrosion-resistant sealing ring is provided between the flange and the elastic circular plate.

4. The wave flow field absorbing sensing device according to claim 1, characterized in that: The optical fibers forming the circle are all tightly bonded to the circular base plate using a corrosion-resistant adhesive.

5. The wave flow field absorbing sensing device according to claim 1, characterized in that: The float is an axisymmetric streamlined shell.

6. The wave flow field absorbing sensing device according to claim 1, characterized in that: The float, support rod, and circular seat plate are all made of corrosion-resistant stainless steel.

7. The wave flow field absorbing sensing device according to claim 1, characterized in that: The support rod is welded to the float and the circular base plate respectively.

8. A wave flow field sensor, characterized in that: This includes a fiber optic strain sensor demodulator with millimeter-level spatial resolution and a microwave absorption sensing module; The wave-absorbing sensing module is composed of at least one wave flow field wave-absorbing sensing device as described in any one of claims 1 to 7 connected in series, wherein the free end of the optical fiber of the wave flow field wave-absorbing sensing device at one end is connected to the optical fiber strain sensor demodulator, and the free end of the optical fiber of the wave flow field wave-absorbing sensing device at the other end is connected to a signal attenuation device.

9. A wave flow field sensor according to claim 8, characterized in that: The fiber optic strain sensor demodulator is an OFDR distributed fiber optic modulator, and the signal attenuation device is a signal attenuator.

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