A composite flat plate flow-induced testing device and method with flow guiding device

Abstract

The application discloses a composite material flat plate flow-induced testing device with a flow guide device and a method, and belongs to the technical field of ship and ocean engineering testing.The application solves the problem that when the existing flow-induced testing device adopts a composite material flat plate to perform flow-induced testing, water flow encounters structural transition and is easy to cause turbulence eddy such as flow separation and backflow, and is easy to affect the vibration noise testing result.The first flow guide structure is used to realize smooth transition between the front flow-encountering surface of the composite material flat plate and the top inner wall of the uniform speed working section, and the second flow guide structure is used to realize smooth transition between the rear flow-encountering surface of the composite material flat plate and the top inner wall of the uniform speed working section.Through the first flow guide structure, the water flow is guided to move along the flow-encountering surface of the composite material flat plate, and the water flow encountering structural transition is avoided to cause adverse effects on measurement.Through the second flow guide structure, the water flow is guided to leave the rear part of the composite material flat plate, and the turbulence eddy such as flow separation and backflow caused by structural transition is avoided to cause adverse effects on measurement.

Description

TECHNICAL FIELD

[0001] The application relates to a composite material flat plate flow-induced test device with a flow guide device and a method thereof, and belongs to the technical field of ship and ocean engineering testing. BACKGROUND

[0002] Ship vibration noise level is crucial to ship comfort, safety, concealment and detection performance, and composite materials have advantages of high strength, lightweight and corrosion resistance compared with traditional metal materials, and are widely applied in underwater vehicles and water surface ships, such as enclosures and sound transmission windows. At present, the dynamic mechanical properties of new materials are less accumulated, and the vibration noise transmission mechanism is not clear.

[0003] A recirculating water channel is a kind of hydrodynamic test equipment that makes water circulate at a certain speed by means of a power system, and a model is placed in the flowing water to measure. Not only is it convenient to measure the speed and pressure, but also observation or video shooting can be carried out through the observation windows on the side and bottom of the channel body, and it has been widely applied in the fields of ship, ocean engineering, sports science and the like.

[0004] In the evaluation of the effectiveness of ship design and composite material replacement, real ship test has a long cycle and is difficult to operate, and therefore it is urgent to develop a test device that can flexibly replace the flat plate and perform performance transverse comparison. The composite material flat plate used in the flow-induced test in the prior art is generally directly placed in the flow field. When the high-speed water flow comes, a low-speed local flow field is easily formed due to the sudden change in cross section, resulting in too small excitation at the front end of the composite material flat plate, and the test result is not good in terms of the change law with the flow speed. When the high-speed water flow leaves the composite material flat plate, the structure transition easily causes adverse turbulent vortex phenomena such as flow separation and backflow, which induces irregular structure vibration and interferes with the test, and therefore it is urgent to solve the flow guide optimization problem of the incoming flow and outgoing flow.

[0005] In order to facilitate simulation verification work, comprehensive physical quantities such as structure surface vibration acceleration, flow field fluctuating pressure load and noise induced by structure vibration should be collected in the test structure at the same time, and the sensors should be directly arranged in the dynamic flow field to avoid disturbing the normal fluid motion, and therefore a test method for the device is urgently needed to be developed. SUMMARY

[0006] The application is to solve the above technical problems, and further provides a composite material flat plate flow-induced test device with a flow guide device and a method thereof.

[0007] The technical scheme adopted by the application to solve the above technical problems is:

[0008] The utility model provides a kind of composite material flat plate flow excitation test device with flow guide device, including noise water tank, uniform velocity work section, first flow guide structure and second flow guide structure, wherein noise water tank is fixed in the top of uniform velocity work section and is communicated between uniform velocity work section, composite material flat plate is located in uniform velocity work section, and the top of composite material flat plate is fixed with noise water tank, smooth transition between the front part of composite material flat plate and the top inner wall of uniform velocity work section is realized by first flow guide structure, and smooth transition between the rear part of composite material flat plate and the top inner wall of uniform velocity work section is realized by second flow guide structure.

[0009] Further, the rear top surface of composite material flat plate is connected between the bottom of noise water tank by Z-shaped hinge, and the front top surface of composite material flat plate is connected between the bottom of noise water tank by L-shaped hinge.

[0010] Further, the left and right side surfaces of composite material flat plate, the left and right side surfaces of first flow guide structure and the left and right side surfaces of second flow guide structure are all sealed and fixed between the left and right side inner walls of uniform velocity work section.

[0011] Further, the noise water tank includes water tank body and mounting plate fixed at the lower part of front and rear ends of water tank body, the water tank body is fixed at the top of uniform velocity work section through the two mounting plates, and the water tank body is sealed and connected with uniform velocity work section.

[0012] Further, the first flow guide structure is wedge-shaped structure, which is made of solid steel material.

[0013] Further, the lower surface of second flow guide structure is streamline-shaped structure, which is made of solid steel material.

[0014] Further, the streamline-shaped structure includes parabola and oblique tangent line smoothly and transitionally connected at the head and tail, wherein the parabola is smoothly and transitionally connected with the rear part of the flow surface of composite material flat plate.

[0015] Further, the top end of first flow guide structure and the top end of second flow guide structure are all sealed and glued with the top inner wall of uniform velocity work section.

[0016] Further, the flow surface of first flow guide structure is provided with rubber skin.

[0017] A test method of the above test device, comprising the following steps:

[0018] Step one, assemble the test device;

[0019] Step two, set a plurality of reserved holes on the composite material flat plate along the central axis at the interval of 150mm-250mm, then pass the pulsating pressure sensor through the reserved hole, so that the top end of the pulsating pressure sensor is flush with the surface of the composite material flat plate, and is filled and fixed with water-proof glue;

[0020] Step three, arrange several acceleration sensors in a matrix form on the composite flat plate, and the interval between each adjacent two acceleration sensors is 100mm-200mm;

[0021] Step four, suspend several hydrophones above the composite flat plate along the central axis at an interval of 300mm-500mm;

[0022] Step five, confirm whether the noise water tank leaks, and if there is a leakage position, timely fill it up;

[0023] Step six, open the water diversion device of the backflow tank, fill the water surface to the top of the backflow tank, and stand still until the water surface has no obvious ripples, connect each sensor, data acquisition instrument and computer without opening the backflow tank pump and valve control console, observe whether each channel is normally running, if normally running, start collecting background vibration, noise and force response, as the basic data noise reference;

[0024] Step seven, open the backflow tank pump and valve control console, observe whether the flow rate monitoring in the system and the real-time readings of each sensor tend to be stable, if stable, start continuous collection for 30s, and then close the pump control system after collection;

[0025] Step eight, adjust the pump control system to different flow rates, and when the flow rate monitoring in the system and the real-time readings of each sensor are stable, continuously collect for 30s, and then close the pump control system after completion;

[0026] Step nine, repeat step eight, after completing the test of the composite flat plate under different flow rates, wait for the water flow to be completely stationary, and repeat the test 2-3 times to reduce test errors and exclude problems caused by manual operation and occasional system errors;

[0027] Step ten, empty the water in the backflow tank, remove each sensor and the composite flat plate, replace the composite flat plate with different thickness and material, and repeat steps one to nine to compare the performance of different materials under the same flow rate;

[0028] Step eleven, after completing the test of the composite flat plate with different thickness and material, wait for the water flow to be completely stationary, empty the water in the backflow tank, remove each sensor, composite flat plate and test device, and the test is completed.

[0029] Compared with the prior art, the present application has the following effects:

[0030] Through the first flow guide structure, the water flow is guided to move along the incident surface of the composite flat plate, avoiding the formation of low-speed local flow field when the water flow encounters a sudden cross section, so that the excitation of the front end of the composite flat plate is too small, and the test result changes irregularly with the flow rate.

[0031] Through the second flow guide structure, the water flow guided out of the back of the composite material flat plate is smoothed, so that the turbulence vortex phenomenon of the water flow encountering the structure and turning is avoided, and the interference peak value in the test is avoided.

[0032] The test device has simple structure, wide application range and easy maintenance, and compared with the prior art, the inside of the noise water tank and the inside of the uniform speed working section are free of other redundant and complex structures, different composite material flat plates and sensors with different parameters such as materials and thicknesses can be replaced according to test requirements, and the device is convenient for disassembly and assembly, data reference is accumulated for research on ship field radiation noise characteristics and composite material shell plates. BRIEF DESCRIPTION OF DRAWINGS

[0033] Figure 1 It is a first three-dimensional structure schematic diagram of the composite material flat plate flow-induced test device with a flow guide device (the water-tight rubber strip is not shown);

[0034] Figure 2 It is a second three-dimensional structure schematic diagram of the composite material flat plate flow-induced test device with a flow guide device (the water-tight rubber strip is not shown);

[0035] Figure 3 It is a third three-dimensional structure schematic diagram of the composite material flat plate flow-induced test device with a flow guide device (the water-tight rubber strip is not shown);

[0036] Figure 4 It is a front view cross-sectional schematic diagram of a working state of the composite material flat plate flow-induced test device with a flow guide device;

[0037] Figure 5 It is a three-dimensional structure schematic diagram of the uniform speed working section;

[0038] Figure 6 It is a three-dimensional structure schematic diagram of the second flow guide structure;

[0039] Figure 7 It is a three-dimensional structure schematic diagram of the first flow guide structure;

[0040] Figure 8 It is a three-dimensional structure schematic diagram of the noise water tank;

[0041] Figure 9 It is a three-dimensional structure schematic diagram of the composite material flat plate;

[0042] Figure 10 It is a streamline schematic diagram of the second flow guide device.

[0043] In the drawings:

[0044] 1, noise water tank; 11, water tank main body; 12, mounting plate; 2, uniform speed working section; 3, first flow guide structure; 4, second flow guide structure; 41, parabola; 42, oblique tangent; 5, composite material flat plate; 51, reserved hole; 6, Z-shaped hinge; 7, L-shaped hinge; 8, pulsatile pressure sensor; 9, acceleration sensor; 10, hydrophone; 100, data acquisition instrument. DETAILED DESCRIPTION

[0045] In combination Figures 1-10 The following embodiments of the present application are described to clarify and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0046] It should be noted that the descriptions of "left", "right", "left side", "right side", "upper", "lower", "top" and "bottom" in the present application are defined based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and are not intended to indicate or imply that the described structure must be constructed and operated in a particular orientation. Therefore, it cannot be understood as a limitation on the present application. In the description of the present application, the meaning of "a plurality of" is two or more, unless otherwise explicitly specified and limited.

[0047] In the description of the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connection" and "connection" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integrally connected; it can be directly connected, or indirectly connected through an intermediate medium; it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0048] Specific embodiment one: a composite material flat plate flow excitation test device with flow guide device, comprising a noise water tank 1, a uniform speed working section 2, a first flow guide structure 3 and a second flow guide structure 4, wherein the noise water tank 1 is fixedly connected to the top end of the uniform speed working section 2 and is in communication with the uniform speed working section 2, the composite material flat plate 5 is located in the uniform speed working section 2, and the top end of the composite material flat plate 5 is fixedly connected with the noise water tank 1, the smooth transition between the front flow surface of the composite material flat plate 5 and the top inner wall of the uniform speed working section 2 is realized through the first flow guide structure 3, and the smooth transition between the rear flow surface of the composite material flat plate 5 and the top inner wall of the uniform speed working section 2 is realized through the second flow guide structure 4.

[0049] In the present application, the direction of the water flow is forward.

[0050] The sealing glue used in the application is water-proof glue.

[0051] The side walls of the noise water tank 1 are made of glass material, which is convenient for observing the internal test condition.

[0052] The uniform speed working section 2 belongs to a part of the backflow water tank, water is introduced into the backflow water tank through the water pump system, and the backflow water tank is internally designed with a special structure, which can effectively generate and control the direction and speed of water flow, so that the structure vibration noise test under a certain flow rate can be realized in the uniform speed working section 2. The left and right sides of the uniform speed working section 2 are glass baffles, the front and rear directions are water-penetrating, and a rectangular through hole is formed in the upper part, which is used for communication with the noise water tank 1. At the same time, through the rectangular through hole formed in the upper end of the uniform speed working section 2, the installation of the composite material plate 5 and various sensors thereon before the test is facilitated.

[0053] The noise water tank 1 contains static water, which simulates the actual working state of the typical structure of the ship, that is, the upper surface and the lower surface of the composite material plate 5 are both in contact with water, the upper surface is in contact with static water, and the lower surface is in contact with flowing water, and the water listener can be hoisted in the noise water tank 1 according to the need, so as to measure the noise in the water on the inner side of the composite material plate 5.

[0054] The top end of the composite material plate 5 is fixedly connected with the noise water tank 1, and specifically, the top end front part and the top end rear part of the composite material plate 5 are respectively fixedly connected with the noise water tank 1.

[0055] The first flow guide structure 3 is fixedly connected with the front end of the composite material plate 5, and the lower surface thereof is smoothly connected with the flow-attacking surface of the composite material plate 5, and the second flow guide structure 4 is fixedly connected with the rear end of the composite material plate 5, and the lower surface thereof is smoothly connected with the flow-attacking surface of the composite material plate 5.

[0056] Through the first flow guide structure 3, the water flow is guided to move along the flow-attacking surface of the composite material plate 5, so as to avoid the formation of a low flow rate local flow field due to the sudden change of the cross section of the water flow, and to avoid the situation that the test result changes irregularly with the flow rate due to the excitation of the front end of the composite material plate being too small.

[0057] Through the second flow guide structure 4, the water flow is guided to leave the rear part of the composite material plate 5, so as to avoid the occurrence of adverse turbulence eddy phenomena such as flow separation and backflow due to the change of the structure, and to avoid the occurrence of interference peaks in the test.

[0058] Compared with the prior art, the test device of the application has simple structure, wide application range and easy maintenance, and the inside of the noise water tank 1 and the inside of the uniform speed working section 2 do not have other redundant and complex structures, so that the composite material plate 5 with different materials, different thicknesses and other parameters can be replaced according to the test requirements, and data reference is accumulated for the research on the ship field radiation noise characteristics and the composite material shell plate.

[0059] The parts are installed in a certain order, and the required sensors such as the acceleration sensor, the fluctuating pressure sensor and the hydrophone are installed and tested. First, the uniform speed working section 2 is installed in the backflow tank, the noise water tank 1 is hoisted and fitted around it, temporary supports are installed to ensure its stability, after installation, the first flow guide structure 3 and the second flow guide structure 4 are pasted to the lower surface of the mounting plate 12 of the noise water tank 1 by structural adhesive, the rear top end of the composite material flat plate 5 is connected to the second flow guide structure 4 and the noise water tank 1 through the Z-shaped hinge 6, organic glass acceleration sensor bases are pasted at equal intervals on the upper surface of the composite material flat plate 5, and the fluctuating pressure sensor reserved hole 51 is punched out with a suitable tool, after the glue is dry, the acceleration sensor is fixed on the organic glass acceleration sensor base using a small full wire stud, the fluctuating pressure sensor is inserted through the reserved hole 51 and the remaining space is filled with glue. After the noise water tank 1 and the sensors are hoisted and moved to above the uniform speed working section 2, the composite material flat plate is slowly lowered to accurately fall in the specified position, the gaps between the first flow guide structure 3, the second flow guide structure 4, the composite material flat plate 5 and the inner walls of the uniform speed working section 2 are filled with water-proof glue, after the glue is completely dry, water is injected into the noise water tank 1, after a period of time, it is detected whether the structure as a whole has a water leakage, and further waterproof work is carried out, the cables of the acceleration sensor and the fluctuating pressure sensor are bundled and pulled out from the rectangular opening at the top of the uniform speed working section 2 and the noise water tank 1, the hydrophone is fixed on the auxiliary support of the noise water tank 1, the cable of the hydrophone is also pulled out from the top of the noise water tank 1, the hydrophone is suspended at the specified position of the noise water tank 1 by the support, and thus the model is completely installed.

[0060] The measuring instruments, collection instruments and computers are connected according to the number, the instrument connection is checked again, and whether there is an abnormality in each signal is checked, if the line signal is abnormal, the line joint and line grounding condition are checked until various faults are excluded to ensure that the line signal is normal. The detected data is first transmitted to the computer storage through the sampling system, the vibration signal collected by the accelerometer needs to be processed by the accelerometer signal conditioner first and then transmitted to the signal collector, the noise signal collected by the hydrophone also needs to be processed by the signal conditioner first and then processed by the transducer power amplifier before being transmitted to the signal collector, and finally all test results are processed and analyzed in the computer terminal.

[0061] The rear top surface of the composite flat plate 5 is connected with the bottom of the noise water tank 1 through a Z-shaped hinge 6, and the front top surface of the composite flat plate 5 is connected with the bottom of the noise water tank 1 through an L-shaped hinge 7. In this way, the L-shaped hinge 7 is a conventional hinge structure, and the Z-shaped hinge 6 is a hinge structure formed by staggered arrangement of three hinge connecting plates and two hinge shafts, which can adjust the specific installation position according to the position and angle of the connected structure. The Z-shaped hinge 6 can also be spliced from two L-shaped hinges 7. The Z-shaped hinge 6 and the L-shaped hinge 7 are fixed to the composite flat plate 5 and the noise water tank 1 through corresponding screw nuts. The rear top surface of the composite flat plate 5, the front end surface of the second flow guide structure 4, and the rear inner wall of the noise water tank 1 are all fixed to the Z-shaped hinge 6, thereby strengthening the fixation of the second flow guide structure 4. In order to ensure the relative sealing of the connection between the noise water tank 1 and the uniform speed working section 2, after the composite flat plate 5 is installed, the outside of the hinge is sealed by sealing glue, or the connection is filled with sealing glue.

[0062] The left and right side surfaces of the composite flat plate 5, the left and right side surfaces of the first flow guide structure 3, and the left and right side surfaces of the second flow guide structure 4 are all sealed and fixed to the left and right side inner walls of the uniform speed working section 2. In this way, it is prevented that the water flow passes through the gaps between the composite flat plate 5 and the uniform speed working section 2, the gaps between the first flow guide structure 3 and the uniform speed working section 2, or the gaps between the second flow guide structure 4 and the uniform speed working section 2, thereby avoiding the water flow impacting the composite flat plate 5, the first flow guide structure 3, and the second flow guide structure 4, and effectively avoiding affecting the accuracy of the test results. The left and right side surfaces of the composite flat plate 5 and the left and right side inner walls of the uniform speed working section 2 are all sealed by water-tight glue, which is sealing glue, as long as it can realize water-tightness between structures.

[0063] The noise water tank 1 comprises a water tank body 11 and mounting plates 12 fixed to the lower parts of the front and rear ends of the water tank body 11. The water tank body 11 is fixed to the top of the uniform speed working section 2 through the two mounting plates 12, and is sealingly connected with the uniform speed working section 2. In this way, the mounting plate 12 is a top cover plate of the uniform speed working section 2. The water tank body 11 and the mounting plate 12 can be connected by welding, bolt fixing, or one-piece forming. The two mounting plates 12 are arranged on the same horizontal plane and are parallel to the top surface of the uniform speed working section 2. The mounting plate 12 and the uniform speed working section 2 are preferably fixed by circumferentially arranged bolts, and the water-tightness between the mounting plate 12 and the uniform speed working section 2 is realized by using rubber gaskets.

[0064] The first flow guide structure 3 is a wedge-shaped structure made of solid steel material.

[0065] The lower surface of the second flow guide structure 4 is a streamline-shaped structure made of solid steel material.

[0066] The streamline structure comprises a parabola 41 and a bevel line 42 which are connected smoothly at the head and tail, wherein the parabola 41 is connected smoothly at the rear of the flow surface of the composite flat plate 5. Thus designed, the streamline can be uniquely determined by the following way: defining the length of the test piece as L E , the angle between the test piece and the plane as α, and the intercept of the parabola 41 on the y-axis as L R , then the specific expression of the parabola 41 is According to the principle of fluid mechanics, the size of the vortex cannot exceed the diameter of the pipeline, while the intercept of the parabola 41 on the y-axis in the present application is short and far less than the diameter of the pipeline, i.e. far less than the height of the inner wall of the uniform speed working section 2. In the present application, the parabola 41 is extended by adding the bevel line 42, so that the total length of the second flow guide device in the horizontal direction is L B . The coordinates of the tangent point A can be obtained according to the geometric relationship, and the calculation formula is as follows: the existing technology will not be repeated here.

[0067] The top end of the first flow guide structure 3 and the top end of the second flow guide structure 4 are both sealed and glued with the top inner wall of the uniform speed working section 2.

[0068] The flow surface of the first flow guide structure 3 is provided with a rubber skin. Thus designed, the flow surface is the surface of the first flow guide structure 3 which contacts with the water flow, and by providing the rubber skin on the flow surface, the first flow guide structure 3 can resist the impact of high-speed water flow and not be deformed obviously, effectively reducing the pulsating pressure of high-speed water flow on the bottom of the noise water tank 1.

[0069] Specific implementation method two: a test method of the above test device, comprising the following steps:

[0070] Step one, assemble the test device; (the gaps between the various component structures involved in the assembly process are filled with sealing glue, and then dried and placed for ≥48h.)

[0071] Step two, a plurality of reserved holes are formed on the composite flat plate along the central axis at an interval of 150mm-250mm, then the pulsating pressure sensor is passed through the reserved hole, so that the top end of the pulsating pressure sensor is flush with the surface of the composite flat plate, and is filled and fixed with water-proof glue; (by forming the reserved hole along the central axis of the composite flat plate and avoiding the connection between the two sides and other structures, the adverse effects of the reserved hole opening on the structure of the composite flat plate can be avoided. Taking a 1800mm composite flat plate as an example, it is recommended to arrange eight pulsating pressure sensors on the central axis of the composite flat plate at an interval of 200mm, with an interval of 100mm from the edges of the plate on both sides, and after the arrangement is completed, the cables are bundled and fixed into a bundle.

[0072] Step three, arrange several acceleration sensors in matrix form on the composite flat plate, the spacing between each adjacent two acceleration sensors is 100mm-200mm; (the acceleration sensor is installed on the composite flat plate through the sensor base, and the acceleration sensor is connected with the sensor base through the self-thread. The acceleration sensor and the pulse pressure sensor are arranged staggered to avoid interference. In order to collect the response data of different parts of the entire composite flat plate as much as possible, several acceleration sensors are arranged in matrix form to cover the surface of the composite flat plate as much as possible. Taking a 1800mm*400mm composite plate as an example, it is recommended to arrange 18 vibration acceleration sensors with a spacing of 100mm along the length direction, and the acceleration sensors located at the edge of the length direction are respectively away from the edge of the composite flat plate by 50mm, and 3 columns of vibration acceleration sensors with a spacing of 150mm are arranged along the width direction, and the acceleration sensors located at the edge of the width direction are respectively away from the two sides of the backflow tank by 50mm, that is, a total of 54 acceleration sensors are arranged, and the cables are bundled and fixed into a bundle after the arrangement is completed.)

[0073] Step four, suspend several hydrophones above the composite flat plate along the central axis with a spacing of 300mm-500mm; (fixed in the noise water tank by means of ordinary steel wire. Taking a 1800mm composite flat plate as an example, 3 hydrophones are arranged on the central axis with a spacing of 400mm, and the cables are bundled and fixed into a bundle after the arrangement is completed.)

[0074] Step five, confirm whether the noise water tank leaks, if there is a leakage position, fill it in time; (slowly inject water into the noise water tank to observe whether there is a leakage position in the noise water tank.)

[0075] Step six, open the backflow tank water diversion device, add water to the top of the backflow tank, and stand still until the water surface has no obvious ripples, connect each sensor, data acquisition instrument and computer without opening the backflow tank water pump and valve control console, observe whether each channel is running normally, if it is normal, start collecting background vibration, noise and force response, as the basic data noise reference;

[0076] Step seven, open the backflow tank water pump and valve control console, observe whether the flow rate monitoring in the system and the real-time readings of each sensor tend to be stable, if it is stable, start continuous collection for 30s, and become closed after collection;

[0077] Step eight, adjust the water pump control system to different flow rates, and when the flow rate monitoring in the system and the real-time readings of each sensor are stable, continuously collect for 30s, and close the water pump control system after completion;

[0078] Step nine, repeat step eight, after the completion of the composite plate test under different flow rates, wait for the water flow to be completely stationary, repeat the test 2-3 times to reduce the test error, to exclude the problems caused by manual operation and occasional system errors;

[0079] Step ten, empty the backflow tank, remove the sensors and composite plates, replace the composite plates of different thickness and material, repeat steps one to nine, and compare the performance of different materials under the same flow rate.

[0080] Step eleven, after the completion of the test of composite plates of different thickness and material, wait for the water flow to be completely stationary, empty the backflow tank, remove the sensors, composite plates and test equipment, and the test is completed.

[0081] Through the installation of the pulsating pressure sensor on the axis of the composite plate, the vibration acceleration sensor on the upper surface of the composite material, and the hydrophone suspended in the noise water tank, the comprehensive physical quantities such as the vibration acceleration of the structure surface, the pulsating pressure load of the flow field, and the noise induced by the structure vibration can be collected simultaneously.

Claims

1. A composite panel flow- induced testing apparatus with flow- guiding means, characterised in that: The system includes a noise tank (1), a constant speed working section (2), a first flow guiding structure (3), and a second flow guiding structure (4). The noise tank (1) is fixedly installed at the top of the constant speed working section (2) and is connected to the constant speed working section (2). The composite material plate (5) is located inside the constant speed working section (2), and the top of the composite material plate (5) is fixedly connected to the noise tank (1). The first flow guiding structure (3) achieves a smooth transition between the front flow-facing surface of the composite material plate (5) and the top inner wall of the constant speed working section (2). The second flow guiding structure (4) achieves a smooth transition between the rear flow-facing surface of the composite material plate (5) and the top inner wall of the constant speed working section (2). The rear top surface of the composite material plate (5) is connected to the bottom of the noise water tank (1) by a Z-shaped hinge (6), and the front top surface of the composite material plate (5) is connected to the bottom of the noise water tank (1) by an L-shaped hinge (7). The first flow guiding structure (3) is a wedge-shaped structure, which is made of solid steel material; The lower surface cross-section of the second flow guiding structure (4) is a streamlined structure, which is made of solid steel material; The streamlined structure includes a parabola (41) and a tangent (42) that are smoothly connected end to end, wherein the parabola (41) is smoothly connected to the rear of the frontal surface of the composite material plate (5).

2. A flat plate hydrodynamic testing device of composite material with flow guiding means according to claim 1, characterized in that: The left and right sides of the composite material plate (5), the left and right sides of the first flow guiding structure (3) and the left and right sides of the second flow guiding structure (4) are all sealed and fixed to the inner walls of the left and right sides of the uniform speed working section (2).

3. A flat plate hydrodynamic testing device of composite material with flow guiding means according to claim 1, characterized in that: The noise water tank (1) includes a water tank body (11) and mounting plates (12) fixed at the lower front and rear ends of the water tank body (11). The water tank body (11) is fixed to the top of the uniform speed working section (2) by the two mounting plates (12), and the water tank body (11) and the uniform speed working section (2) are sealed together.

4. The flat plate hydrodynamic testing apparatus of claim 1, wherein: The top of the first flow guiding structure (3) and the top of the second flow guiding structure (4) are both sealed and bonded to the top inner wall of the uniform speed working section (2).

5. The composite flat plate hydrodynamic testing device with flow guide device according to claim 1, characterized in that: The front surface of the first flow guiding structure (3) is provided with a rubber skin.

6. A test method for the test device according to any one of claims 1 to 5, characterized in that: Includes the following steps: Step 1: Assemble the testing device; Step 2: Make several pre-drilled holes along the central axis of the composite material plate at intervals of 150mm to 250mm, then pass the pulsating pressure sensor through the pre-drilled holes so that the top of the pulsating pressure sensor is flush with the surface of the composite material plate, and fill and fix it with water-tight adhesive. Step 3: Arrange several accelerometers in a matrix on the composite material plate, with a spacing of 100mm to 200mm between each adjacent accelerometer. Step 4: Suspend several hydrophones at intervals of 300mm to 500mm along the central axis above the composite material plate; Step 5: Check if the noise-generating water tank is leaking. If there is a leak, repair it promptly. Step six, open the water supply device of the backwater tank, add water to the top of the backwater tank, and stand still until the water surface is smooth. Connect the sensors, data acquisition instruments and computers without opening the backwater tank pump and valve control console. Observe whether the channels are running normally. If they are running normally, start collecting background vibration, noise and force response data as a reference for the noise floor. Step seven, open the backwater tank pump and valve control console. Observe whether the flow rate monitoring and real-time sensor readings in the system are stable. If they are stable, start collecting data continuously for 30 seconds. Turn off the pump control system after collecting data. Step eight, adjust the pump control system to different flow rates. When the flow rate monitoring and real-time sensor readings in the system are stable, collect data continuously for 30 seconds. Turn off the pump control system after completing the collection. Step nine, repeat step eight. After testing the composite plate at different flow rates, wait for the water flow to stop completely. Repeat the test 2-3 times to reduce test errors and eliminate problems caused by human operation and occasional system errors. Step ten, empty the water in the backwater tank, remove the sensors and composite plates, replace the composite plates with different thicknesses and materials, and repeat steps one to nine to compare the performance of different materials at the same flow rate. Step eleven, after testing the composite plates with different thicknesses and materials, wait for the water flow to stop completely, empty the water in the backwater tank, remove the sensors, composite plates and test devices, and the test is complete.

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