Double-fluctuation hydrofoil hydrodynamic interference measurement and flow field visualization experiment device and method

Abstract

The invention discloses a double-fluctuation hydrofoil hydrodynamic interference measurement and flow field visualization experiment device and method, and belongs to the technical field of bionic engineering. The two hydrofoil position adjusting structures of the experimental device are detachably installed on the circulating water tank side by side in parallel, the high-speed camera is installed on the outer side of the circulating water tank, and each hydrofoil position adjusting structure comprises a horizontal sliding beam, a vertical lifting rod and a connecting sliding block. The horizontal sliding beam is connected with the vertical lifting rod through the connecting sliding block, the horizontal sliding beam is located at the top of the circulating water tank, the vertical lifting rod is located in the circulating water tank, the six-component force sensor is installed on the vertical lifting rod, and the fluctuation hydrofoil is installed at the bottom of the vertical lifting rod. The device can accurately simulate the fluctuating motion of the robotic fish, does not depend on a post-processing program, can conveniently provide real-time three-dimensional flow display in a test, and can rapidly carry out a large number of double-fish-imitating fluctuating hydrofoil dynamics tests.

Description

Technical Field

[0001] The invention relates to a wave hydrofoil experimental device and method, in particular to a double wave hydrofoil hydrodynamic interference measurement and flow field visualization experimental device and method, belonging to the technical field of bionic engineering. Background Art

[0002] Bionic robot fish have been playing a unique role in underwater resource exploration, marine environmental protection and military reconnaissance. In recent years, with the continuous increase in engineering needs, a single robot fish is often difficult to complete complex systematic tasks. In this case, the collaborative operation of a dual robot fish formation shows irreplaceable advantages. For the design of robot fish formations, conducting a dual model fish hydrodynamic response measurement test is the key and basis. At present, mature technical solutions mostly use pitching and sinking wing or thin plates to replace the undulating robot fish body. This pitching and sinking action is still quite different from the wave-like swing of the robot fish body, and it is difficult to accurately simulate the undulating motion of the robot fish. In addition, although the traditional particle image velocimeter can provide high-precision flow field information, it relies on post-processing programs and cannot visualize the wake field of the undulating hydrofoil in real time. In addition, the flow around the undulating hydrofoil has a three-dimensional effect. The traditional two-dimensional particle image velocimeter is difficult to fully capture the three-dimensional flow field information, and the three-dimensional particle image velocimeter is still expensive at present. At present, a wake visualization device based on pulse lines can conveniently provide real-time three-dimensional flow display in the experiment and ensure low test costs. In view of the above problems and needs, it is necessary to design a hydrodynamic interference measurement and flow field visualization experimental device and its test method for double-wave hydrofoils, which can not only meet actual engineering needs but also have important application value. Summary of the invention

[0003] The present invention improves on the above-mentioned shortcomings in the prior art and further proposes a dual undulating hydrofoil hydrodynamic interference measurement and flow field visualization experimental device and method, which can accurately simulate the undulating motion of the robot fish, is independent of post-processing programs, can conveniently provide real-time three-dimensional flow display in the experiment, and can quickly carry out a large number of dual fish-like undulating hydrofoil dynamics tests, which is convenient for studying the propulsion mechanism of dual bionic fish. The test cost is low and the efficiency is high, and a large amount of test data can be obtained in a short time.

[0004] The technical solution adopted by the present invention is as follows:

[0005] A dual-wave hydrofoil hydrodynamic interference measurement and flow field visualization experimental device comprises a circulating water tank, two hydrofoil position adjustment structures, two wave hydrofoils, two six-component force sensors and a high-speed camera, wherein the two hydrofoil position adjustment structures are detachably mounted on the circulating water tank in parallel and side by side, the high-speed camera is mounted on the outside of the circulating water tank, the hydrofoil position adjustment structure comprises a horizontal sliding beam, a vertical lifting rod and a connecting slider, the horizontal sliding beam is connected to the vertical lifting rod through the connecting slider, the horizontal sliding beam is located at the top of the circulating water tank, the vertical lifting rod is located inside the circulating water tank, the six-component force sensor is mounted on the vertical lifting rod, and the wave hydrofoil is mounted on the bottom of the vertical lifting rod.

[0006] Furthermore, the undulating hydrofoil includes a rigid hydrofoil head, a flexible hydrofoil wing body, a rigid hydrofoil tail, a hydrofoil internal truss, a servo, and a dye nozzle. The rigid hydrofoil head, the flexible hydrofoil wing body and the rigid hydrofoil tail are connected in sequence from the head to the tail of the undulating hydrofoil. The hydrofoil internal truss is installed inside the undulating hydrofoil. The servo is installed in the rigid hydrofoil head. The dye nozzle is installed at the tail of the rigid hydrofoil tail. The rigid hydrofoil head is connected to the vertical lifting rod.

[0007] Furthermore, the circulating water tank includes a water tank container, an elbow guide plate, a honeycomb rectifier and a horizontal guide rail. The water tank container is the frame of the circulating water tank and is in the shape of a rectangular parallelepiped. The elbow guide plate is arranged at the corner of the water tank container, the honeycomb rectifier is arranged inside the water tank container, and the horizontal guide rail is opened on the upper part of the side wall of the water tank container.

[0008] Furthermore, there are two elbow guide plates, and the two elbow guide plates are respectively arranged at the corners on both sides of the water tank container.

[0009] Furthermore, the hydrofoil position adjustment structure also includes a horizontal slider and a locking device, wherein the horizontal slider is installed in the horizontal guide rail, and the locking device is installed on the outside of the horizontal slider.

[0010] Furthermore, the hydrofoil position adjustment structure further comprises a dye tank and a dye tube, wherein the dye tank is fixedly mounted on the connecting slider, and the dye tube is mounted between the dye tank and the dye nozzle.

[0011] Furthermore, the locking device is a locking nut that is conformable to the horizontal sliding beam.

[0012] Furthermore, the six-component force sensor is used to measure the resultant force in three directions and the torque in three directions of the wave hydrofoil, and the six-component force sensor is communicatively connected to a remote data receiving device.

[0013] Furthermore, the high-speed camera includes a high-resolution sensor, which can provide clear picture quality at a high frame rate and communicate with the remote data receiving device.

[0014] Furthermore, the remote data receiving device is one of a computer, a mobile phone and a tablet.

[0015] A test method for a double-wave hydrofoil hydrodynamic interference measurement and flow field visualization experimental device, the test method is achieved by the following steps:

[0016] S1: Install two hydrofoil position adjustment structures on the circulating water tank;

[0017] S2: installing a six-component force sensor and two undulating hydrofoils, and adjusting the initial relative positions of the two undulating hydrofoils through a hydrofoil position adjustment structure;

[0018] S3: Control the two wave hydrofoils to make periodic wave-like swings;

[0019] S4: Adjust the horizontal relative position d of the two undulating hydrofoils through the hydrofoil position adjustment structure x , relative position d y and vertical relative position d z , explore the influence of the relative position between two undulating hydrofoils on the propulsion performance of the undulating hydrofoils;

[0020] S5: Adjust the phase difference Δφ of the periodic swing of the two waving hydrofoils, adjust the period ratio γ of the swing of the two waving hydrofoils, and adjust the amplitude ratio ψ of the swing of the two waving hydrofoils to explore the influence of the phase difference Δφ, period ratio γ, and amplitude ratio ψ on the propulsion performance of the two waving hydrofoils;

[0021] S6: Control the two undulating hydrofoils to form veins during their motion;

[0022] S7: Use a six-component force sensor to record the load data of the two wave hydrofoils, and post-process to obtain the hydrodynamic coefficient and hydrodynamic moment coefficient;

[0023] S8: According to the flow rate U controlled in the circulating water tank and the power consumption P of the motor in and the horizontal force load F of the six-component force sensor x The propulsion efficiency η of the undulating hydrofoil is obtained by post-processing;

[0024] S9: The evolution of the vein lines in the wakes of two undulating hydrofoils is captured with a high-speed camera.

[0025] Furthermore, the expression of the periodic wave-like oscillation described in S3 is as follows:

[0026]

[0027] In formula (1), z1(t) and z2(t) are the vertical positions of the tail ends of the two fluctuating hydrofoils at time t, A1 and A2 are the amplitudes of the two fluctuating hydrofoils, ω1 and ω2 are the angular frequencies of the two fluctuating hydrofoils, ω1 = 2π / T1, ω2 = 2π / T2, where T1 and T2 are the fluctuation periods of the two fluctuating hydrofoils, and φ1 and φ2 are the phase angles of the fluctuations of the two fluctuating hydrofoils.

[0028] Furthermore, the hydrodynamic coefficient and hydrodynamic moment coefficient expressions described in S7 are as follows:

[0029]

[0030] In formula (2) and formula (3), F x , F y and F z Respectively represent the forces in three directions on the wave hydrofoil; Q x , Q y and Q z They represent the moments in three directions respectively, ρ represents the density of water, U represents the incoming flow velocity, and L represents the chord length of the airfoil.

[0031] Furthermore, the propulsion efficiency η described in S8 is expressed as follows:

[0032]

[0033] The beneficial effects of the present invention are:

[0034] 1. The present invention generates the pulse line in the wake by spraying dye from the dye nozzle, which can conveniently display the flow in the wake in real time. The relative position, period ratio and amplitude ratio between the two wavy hydrofoils can be controlled by the hydrofoil position adjustment structure, so as to further explore the influence of these parameters on the propulsion mechanism of the dual bionic fish and realize the wave-like swing closer to the motion mode of the bionic fish.

[0035] 2. The present invention can analyze the propulsion mechanism of bionic fish by outputting load data through a six-component force sensor and combining it with the evolution of wake veins captured by a high-speed camera.

[0036] 3. The hydrodynamic measurement and flow field display device of the double-wave hydrofoil of the present invention has good scalability and can be easily developed into a hydrodynamic measurement and flow field display device of a multi-wave hydrofoil. The test cost is low and the efficiency is high. A large amount of test data can be obtained in a short time. These test data are helpful to support scientific research in the field of bionics. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 It is a structural schematic diagram of an embodiment of a double-wave hydrofoil hydrodynamic interference measurement and flow field visualization experimental device of the present invention;

[0038] Figure 2 It is a schematic structural diagram of an embodiment of the wave hydrofoil of the present invention;

[0039] Figure 3 It is a structural schematic diagram of an embodiment of a circulating water tank of the present invention;

[0040] Figure 4 It is a structural schematic diagram of an implementation mode of the hydrofoil position adjustment structure of the present invention;

[0041] Figure 5 It is a structural schematic diagram of an embodiment of the present invention in which a wave hydrofoil flows with a water flow;

[0042] Figure 6 It is a schematic diagram of an embodiment of the undulating hydrofoil wake forming vein line of the present invention.

[0043] In the figure: 1. Rigid hydrofoil head; 2. Flexible hydrofoil wing body; 3. Rigid hydrofoil tail; 4. Internal truss of hydrofoil; 5. Servo; 6. Dye nozzle; 7. Water tank container; 8. Elbow guide plate; 9. Honeycomb rectifier; 10. Horizontal guide rail; 11. Horizontal slider; 12. Locking device; 13. Horizontal sliding beam; 14. Vertical lifting rod; 15. Six-component force sensor; 16. Connecting slider; 17. Dye tank; 18. Dye tube; 19. High-speed camera. DETAILED DESCRIPTION

[0044] In the description of the present invention, it should be noted that all directional indications (such as horizontal, vertical, etc.) are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0045] Specific implementation method 1: Combination Figure 1-6 To illustrate this embodiment, Figure 1As shown, a dual-wave hydrofoil hydrodynamic interference measurement and flow field visualization experimental device described in this embodiment includes a circulating water tank, two hydrofoil position adjustment structures, two wave hydrofoils, two six-component force sensors 15 and a high-speed camera 19. The high-speed camera 19 is installed outside the circulating water tank. Preferably, the high-speed camera 19 includes a high-resolution sensor that can provide clear picture quality at a high frame rate. The two hydrofoil position adjustment structures are detachably installed side by side on the circulating water tank. The hydrofoil position adjustment structure is used to control the position of the wave hydrofoil and provide boundary support for the wave hydrofoil. The hydrofoil position adjustment structure includes a horizontal sliding beam 13, a vertical lifting rod 14 and a connecting slider 16. The horizontal sliding beam 13 is connected to the vertical lifting rod 14 through the connecting slider 16. The horizontal sliding beam 13 is located at the top of the circulating water tank, and the vertical lifting rod 14 is located inside the circulating water tank to control the position of the wave hydrofoil. The six-component force sensor 15 is installed on the vertical lifting rod 14 to measure the resultant force in three directions and the torque in three directions of the wave hydrofoil. Preferably, the six-component force sensor 15 and the high-speed camera 19 are communicatively connected with a remote data receiving device, which is one of a computer, a mobile phone and a tablet, and supports remote control and real-time data transmission. The wave hydrofoil is installed at the bottom of the vertical lifting rod 14 to simulate the activities of the bionic fish underwater.

[0046] like Figure 2 As shown, the undulating hydrofoil includes a rigid hydrofoil head 1, a flexible hydrofoil wing body 2, a rigid hydrofoil tail 3, a hydrofoil internal truss 4, a servo 5, and a dye nozzle 6. The rigid hydrofoil head 1, the flexible hydrofoil wing body 2, and the rigid hydrofoil tail 3 are sequentially connected from the head to the tail of the undulating hydrofoil. The rigid hydrofoil head 1 and the rigid hydrofoil tail 3 are supported by rigid materials to ensure the stability of the undulating hydrofoil when subjected to external forces, so that the head of the undulating hydrofoil can effectively withstand the fluid force and avoid excessive deformation in the flow field. The flexible hydrofoil wing body 2 is used for waving. The hydrofoil internal truss 4 is installed inside the undulating hydrofoil. The hydrofoil internal truss 4 provides necessary internal support for the flexible hydrofoil wing body 2, so that the flexible hydrofoil wing body 2 can maintain sufficient flexibility while avoiding instability and damage due to excessive bending. After the undulating hydrofoil is deformed by the flow of water, Figure 5 shown.

[0047] The servo 5 is installed in the rigid hydrofoil head 1, and the servo 5 provides power for the wavy swing of the flexible hydrofoil wing body 2. Preferably, the servo 5 is a brushless motor and is connected to a control device for controlling the rotation speed of the servo 5. It is used to provide stable and precise control. The servo 5 controls the fluctuation period, amplitude and other parameters of the wavy hydrofoil to achieve the desired fluctuation form. The dye nozzle 6 is installed at the tail of the rigid hydrofoil tail 3, and the dye nozzle 6 is used to stably and continuously spray dye to form a pulse line to visualize the wake field.

[0048] like Figure 3 As shown, the circulating water tank includes a water tank container 7, an elbow guide plate 8, a honeycomb rectifier 9 and a horizontal guide rail 10. The water tank container 7 is the basic frame of the circulating water tank and is in the shape of a rectangular parallelepiped. The elbow guide plate 8 is arranged at the corner of the water tank container 7 to guide the water flow. Preferably, the elbow guide plate 8 is in the shape of a multi-layer concentric semicircle with equal spacing, and the center direction of the elbow guide plate 8 is toward the center direction of the circulating water tank. The number of the elbow guide plates 8 is two, and the two elbow guide plates 8 are respectively arranged at the corners on both sides of the water tank container 7 to effectively change the flow direction of the fluid and reduce the turbulence caused by the turn. The honeycomb rectifier 9 is arranged inside the water tank container 7. Preferably, the honeycomb rectifier 9 is composed of a honeycomb structure and is in the shape of a rectangular parallelepiped. The honeycomb rectifier 9 can reduce the turbulence of the flow through the channels formed by the honeycomb structure, ensuring that the fluid can produce uniform incoming flow conditions after passing through the honeycomb rectifier 9. The horizontal guide rail 10 is disposed on the upper portion of the side wall of the water tank container 7 , namely, the upper edge of the water tank container 7 , and cooperates with the hydrofoil position adjustment structure to move and fix the hydrofoil position adjustment structure.

[0049] like Figure 4As shown, the hydrofoil position adjustment structure includes a horizontal sliding beam 13, a vertical lifting rod 14, a connecting slider 16, a horizontal slider 11 and a locking device 12, a dye tank 17 and a dye tube 18. The horizontal sliding beam 13 is connected to the vertical lifting rod 14 through the connecting slider 16. Preferably, the connecting slider 16 can be slidably connected on the horizontal sliding beam 13. Screws that can fix the slider are provided on both sides of the connecting slider 16. A gap for the vertical lifting rod 14 to pass through and screws for fixing the vertical lifting rod 14 are provided on the connecting slider 16. The horizontal sliding beam 13 allows the wave hydrofoil to accurately adjust its position in the horizontal plane. The vertical lifting rod 14 is connected to the rigid hydrofoil head 1 to control the lifting height of the wave hydrofoil. The horizontal slider 11 is installed in the horizontal guide rail 10, and the locking device 12 is installed on the outside of the horizontal slider 11. Preferably, the locking device 12 is a locking nut that conforms to the horizontal sliding beam 13. The position of the hydrofoil is controlled by the horizontal slider 11, and the locking device 12 can take effect quickly after the position is adjusted to ensure that the position of the hydrofoil will not drift due to vibration or external interference. The dye tank 17 is fixedly installed on the connecting slider 16 and is used to store dye; the dye tube 18 is installed between the dye tank 17 and the dye nozzle 6 and is used to connect the dye tank 17 and the dye nozzle 6 to transfer the dye in the dye tank 17 to the dye nozzle 6. Figure 6 As shown, the dye is sprayed from the dye tank 17 through the dye tube 18 to the dye nozzle 6, and forms a pulse line as the water flows backward, which is convenient for observing the undulating hydrofoil and can conveniently display the flow in the wake in real time.

[0050] A test method for a double-wave hydrofoil hydrodynamic interference measurement and flow field visualization experimental device, the test method is achieved by the following steps:

[0051] S1: Install two hydrofoil position adjustment structures on the circulating water tank;

[0052] S2: installing the six-component force sensor 15 and two undulating hydrofoils, and adjusting the initial relative positions of the two undulating hydrofoils through the hydrofoil position adjustment structure;

[0053] S3: Control the two hydrofoils to make periodic wave-like swings; control the two hydrofoils to make periodic wave-like swings by adjusting the rotation speed and control mode of the steering gear 5. The expression of the periodic wave-like swing is as follows:

[0054]

[0055] In formula (1), z1(t) and z2(t) are the vertical positions of the tail ends of the two fluctuating hydrofoils at time t, A1 and A2 are the amplitudes of the two fluctuating hydrofoils, ω1 and ω2 are the angular frequencies of the two fluctuating hydrofoils, ω1 = 2π / T1, ω2 = 2π / T2, where T1 and T2 are the fluctuation periods of the two fluctuating hydrofoils, and φ1 and φ2 are the phase angles of the fluctuations of the two fluctuating hydrofoils.

[0056] S4: Adjust the horizontal relative position d of the two undulating hydrofoils through the hydrofoil position adjustment structure x , relative position d y and vertical relative position d z , explore the influence of the relative position between two undulating hydrofoils on the propulsion performance of the undulating hydrofoils;

[0057] S5: Adjust the phase difference Δφ of the periodic swing of the two waving hydrofoils, adjust the period ratio γ of the swing of the two waving hydrofoils, and adjust the amplitude ratio ψ of the swing of the two waving hydrofoils to explore the influence of the phase difference Δφ, period ratio γ, and amplitude ratio ψ on the propulsion performance of the two waving hydrofoils;

[0058] Specifically, through the adjustment of the steering gear 5, the phase difference of the periodic swing of the two wave hydrofoils is Δφ=φ1-φ2;

[0059] The period ratio of the swinging of the two hydrofoils is γ = T1 / T2;

[0060] The amplitude ratio of the swinging of the two hydrofoils is ψ=A1 / A2.

[0061] S6: Control the two undulating hydrofoils to form a pulse line during the movement; spray dye through the dye nozzle 6 to form a pulse line during the movement of the two undulating hydrofoils.

[0062] S7: Use the six-component force sensor 15 to record the load data of the two wave hydrofoils, and post-process to obtain the hydrodynamic coefficient and the hydrodynamic moment coefficient; the hydrodynamic coefficient and the hydrodynamic moment coefficient are expressed as follows:

[0063]

[0064] In formula (2) and formula (3), F x , F y and F z Respectively represent the forces in three directions on the wave hydrofoil; Q x , Q y and Q z They represent the moments in three directions respectively, ρ represents the density of water, U represents the incoming flow velocity, and L represents the chord length of the airfoil.

[0065] S8: According to the flow rate U controlled in the circulating water tank and the power consumption P of the motor inand the horizontal force load F of the six-component force sensor 15 x The propulsion efficiency η of the wave hydrofoil is obtained by post-processing; the propulsion efficiency η is expressed as follows:

[0066]

[0067] S9: The evolution of the vein lines in the wakes of two undulating hydrofoils is filmed with a high-speed camera19.

[0068] Experimental method for hydrodynamic disturbance measurement and flow field visualization experimental device of double undulating hydrofoils

[0069] Specifically, the test method of the double-wave hydrofoil hydrodynamic interference measurement and flow field visualization experimental device is as follows:

[0070] 1) Installation and preparation

[0071] Two hydrofoil position adjustment structures are installed on the circulating water tank to ensure that the two wave hydrofoils can be accurately adjusted and positioned in the water tank. The six-component force sensor 15 is installed on the vertical lifting rod 14, and the initial position of the hydrofoil is adjusted by the hydrofoil position adjustment mechanism to ensure that it is in the correct experimental position. The six-component force sensor 15 and the high-speed camera 19 are calibrated to ensure that the shooting angle, frequency, and resolution of the high-speed camera 19 meet the experimental requirements, and the measurement accuracy of the sensor is verified.

[0072] 2) Test operation

[0073] Start two steering gears 5, adjust the rotation speed and control mode of steering gears 5 respectively, and control the periodic wavy swing of two undulating hydrofoils. Adjust the parameters of steering gear 5 to ensure that the amplitude and frequency of the undulating hydrofoils meet the experimental requirements. Start the dye nozzle 6 to ensure that it sprays dye stably and continuously, forming a pulse line and evolving in the wake of the hydrofoil. The injection of the dye pulse line is synchronized with the fluctuation of the hydrofoil, which helps to observe the flow field changes.

[0074] 3) Data recording and detection

[0075] A six-component force sensor 15 is used to record the load data of the two undulating hydrofoils at different time points. The data of the force sensor can show the force conditions of the undulating hydrofoil during the undulation process, including the changes in the resultant force and torque. A high-speed camera 19 is used to film the evolution of the dye veins in the hydrofoil wake. The video records the dynamic changes of the flow field and provides visual information on the interaction between the hydrofoil motion and the flow field.

[0076] 4) Data analysis

[0077] According to the load data of the six-component force sensor 15, the hydrodynamic characteristics of the hydrofoil are analyzed, and its force and propulsion efficiency under different control conditions are explored. By analyzing the video captured by the high-speed camera 19, the movement trajectory of the dye vein is observed, the change of the flow field is studied, and the relationship between the movement of the hydrofoil and the change of the flow field is revealed.

[0078] The present invention can autonomously control the frequency and amplitude of the wavy swing of two wavy hydrofoils, and can start the nozzles at the tail of the two wavy hydrofoils to spray dye. The positions of the two wavy hydrofoils in the water tank can be accurately adjusted; the hydrodynamic load of the wavy hydrofoils waving in waves with different frequencies and amplitudes can be measured, and the test data can be exported for analysis through a six-component force sensor; and a picture of the evolution of the wake flow field of the wavy hydrofoil can be obtained based on a high-speed camera. The test method performed by the present invention is easy to operate, and can quickly carry out a large number of dual fish-like wavy hydrofoil dynamic tests, which is convenient for studying the propulsion mechanism of dual bionic fish.

[0079] The above is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technician familiar with this profession can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent replacement and improvement made to the above embodiments without departing from the content of the technical solution of the present invention, based on the technical essence of the present invention, within the spirit and principles of the present invention, still fall within the protection scope of the technical solution of the present invention.

Claims

1. A double-wave hydrofoil hydrodynamic interference measurement and flow field visualization experimental device, characterized in that: The invention comprises a circulating water tank, two hydrofoil position adjustment structures, two wave hydrofoils, two six-component force sensors (15) and a high-speed camera (19), wherein the two hydrofoil position adjustment structures are detachably mounted on the circulating water tank in parallel and side by side, the high-speed camera (19) is mounted on the outside of the circulating water tank, the hydrofoil position adjustment structure comprises a horizontal sliding beam (13), a vertical lifting rod (14) and a connecting slider (16), the horizontal sliding beam (13) and the vertical lifting rod (14) are connected via the connecting slider (16), the horizontal sliding beam (13) is located at the top of the circulating water tank, the vertical lifting rod (14) is located inside the circulating water tank, the six-component force sensor (15) is mounted on the vertical lifting rod (14), and the wave hydrofoil is mounted at the bottom of the vertical lifting rod (14).

2. A double-wave hydrofoil hydrodynamic interference measurement and flow field visualization experimental device according to claim 1, characterized in that: The undulating hydrofoil comprises a rigid hydrofoil head (1), a flexible hydrofoil wing body (2), a rigid hydrofoil tail (3), a hydrofoil internal truss (4), a steering gear (5), and a dye spray pipe (6). The rigid hydrofoil head (1), the flexible hydrofoil wing body (2), and the rigid hydrofoil tail (3) are sequentially connected from the head to the tail of the undulating hydrofoil. The hydrofoil internal truss (4) is installed inside the undulating hydrofoil. The steering gear (5) is installed in the rigid hydrofoil head (1). The dye spray pipe (6) is installed at the tail of the rigid hydrofoil tail (3). The rigid hydrofoil head (1) is connected to the vertical lifting rod (14).

3. A double-wave hydrofoil hydrodynamic interference measurement and flow field visualization experimental device according to claim 2, characterized in that: The circulating water tank comprises a water tank container (7), an elbow guide plate (8), a honeycomb rectifier (9) and a horizontal guide rail (10); the water tank container (7) is a frame of the circulating water tank in the shape of a rectangular parallelepiped; the elbow guide plate (8) is arranged at a corner of the water tank container (7); the honeycomb rectifier (9) is arranged inside the water tank container (7); and the horizontal guide rail (10) is opened on the upper part of the side wall of the water tank container (7).

4. The double-wave hydrofoil hydrodynamic interference measurement and flow field visualization experimental device according to claim 3 is characterized by: The hydrofoil position adjustment structure further comprises a horizontal slider (11), a locking device (12), a dye tank (17) and a dye tube (18); the horizontal slider (11) is installed in the horizontal guide rail (10); the locking device (12) is installed on the outside of the horizontal slider (11); the dye tank (17) is fixedly installed on the connecting slider (16); and the dye tube (18) is installed between the dye tank (17) and the dye nozzle (6).

5. The double-wave hydrofoil hydrodynamic interference measurement and flow field visualization experimental device according to claim 1 is characterized by: The six-component force sensor (15) is used to measure the resultant force in three directions and the torque in three directions of the wave hydrofoil, and the six-component force sensor (15) is communicatively connected to a remote data receiving device.

6. The double-wave hydrofoil hydrodynamic interference measurement and flow field visualization experimental device according to claim 5 is characterized by: The high-speed camera (19) includes a high-resolution sensor and can provide clear picture quality at a high frame rate and is communicatively connected to the remote data receiving device.

7. A test method for the double-wave hydrofoil hydrodynamic interference measurement and flow field visualization experimental device according to claim 1, characterized in that: The test method is achieved by the following steps: S1: Install two hydrofoil position adjustment structures on the circulating water tank; S2: installing a six-component force sensor (15) and two undulating hydrofoils, and adjusting the initial relative positions of the two undulating hydrofoils through a hydrofoil position adjustment structure; S3: Control the two wave hydrofoils to make periodic wave-like swings; S4: Adjust the horizontal relative position d of the two undulating hydrofoils through the hydrofoil position adjustment structure x , relative position d y and vertical relative position d z , explore the influence of the relative position between two undulating hydrofoils on the propulsion performance of the undulating hydrofoils; S5: Adjust the phase difference Δφ of the periodic swing of the two waving hydrofoils, adjust the period ratio γ of the swing of the two waving hydrofoils, and adjust the amplitude ratio ψ of the swing of the two waving hydrofoils to explore the influence of the phase difference Δφ, period ratio γ, and amplitude ratio ψ on the propulsion performance of the two waving hydrofoils; S6: Control the two undulating hydrofoils to form veins during their motion; S7: using a six-component force sensor (15) to record the load data of the two wave hydrofoils, and post-processing to obtain the hydrodynamic coefficient and the hydrodynamic moment coefficient; S8: According to the flow rate U controlled in the circulating water tank and the power consumption P of the motor in and the horizontal force load F of the six-component force sensor (15) x The propulsion efficiency η of the undulating hydrofoil is obtained by post-processing; S9: The evolution of the veins in the wakes of two undulating hydrofoils was captured using a high-speed camera (19).

8. The test method of the double-wave hydrofoil hydrodynamic interference measurement and flow field visualization experimental device according to claim 7 is characterized by: The expression for the periodic wave-like oscillation described in S3 is as follows: In formula (1), z1(t) and z2(t) are the vertical positions of the tail ends of the two fluctuating hydrofoils at time t, A1 and A2 are the amplitudes of the two fluctuating hydrofoils, ω1 and ω2 are the angular frequencies of the two fluctuating hydrofoils, ω1 = 2π / T1, ω2 = 2π / T2, where T1 and T2 are the fluctuation periods of the two fluctuating hydrofoils, and φ1 and φ2 are the phase angles of the fluctuations of the two fluctuating hydrofoils.

9. The test method of the double-wave hydrofoil hydrodynamic interference measurement and flow field visualization experimental device according to claim 8 is characterized by: The expressions for the hydrodynamic coefficient and hydrodynamic moment coefficient described in S7 are as follows: In formula (2) and formula (3), F x , F y and F z Respectively represent the forces in three directions on the wave hydrofoil; Q x , Q y and Q z They represent the moments in three directions respectively, ρ represents the density of water, U represents the incoming flow velocity, and L represents the chord length of the airfoil.

10. The test method of the double-wave hydrofoil hydrodynamic interference measurement and flow field visualization experimental device according to claim 9 is characterized in that: The propulsion efficiency η described in S8 is expressed as follows:

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