Underwater vibration table disturbance wave active elimination method and device based on potential flow theory

Abstract

The invention discloses an underwater vibration table disturbance wave active elimination method and device based on a potential flow theory. According to the movement time history of the vibration table and the physical characteristics of the pool, waveform information of disturbance waves is calculated; acquiring a propagation distance from the wave making plate to the underwater vibration table; calculating the propagation speed of the disturbance wave; calculating a target moment when the disturbance wave is propagated to the wave making plate based on the propagation speed and the propagation distance; at the target moment, the wave maker is started, the displacement of a push plate of the wave maker is calculated in real time according to the waveform information, and a wave surface opposite to the disturbance wave is generated. The wave surface equation of the disturbance wave of the underwater vibration table is deduced based on the potential flow theory, and the propagation speed of the disturbance wave, the time for reaching the target area and the like can be accurately predicted. The displacement of the push plate of the wave generator is accurately controlled in real time according to the waveform information of the disturbance wave, and a waveform opposite to the disturbance wave is generated for active absorption. The real-time elimination of the disturbance waves is realized, and the elimination strategy can be adjusted according to the dynamic change of the disturbance waves in the pool.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of water flow wave abatement, and more particularly to an underwater vibration table disturbance wave active elimination method and device based on potential flow theory. BACKGROUND

[0002] In the experiment of the underwater vibration table, the vibration of the vibration table will cause disturbance waves, which not only affect the stability of the experimental environment, but also can have a significant impact on the test results. Especially in precise experiments, the disturbance waves caused by the vibration of the underwater vibration table are easy to interfere with other test equipment, reduce the experimental precision, and even make the experiment unable to proceed smoothly. Therefore, how to effectively suppress and eliminate the disturbance waves generated by the underwater vibration table has become a technical problem to be solved in underwater vibration experiments.

[0003] In the past research and application, there have been some methods to try to weaken the disturbance waves generated by the underwater vibration table, such as through physical barriers (such as breakwaters, wave abatement plates, etc.) or using wave makers to generate opposite waveforms for interference. Among them, the interference through physical barriers is mainly to prevent the propagation of disturbance waves or guide them to the edge of the pool to minimize the impact of waves, but the physical method does not have precise wave control ability and cannot be adjusted in real time according to the characteristics of the disturbance waves. The method of using wave makers to generate opposite waveforms to eliminate waves is mainly based on experimental or theoretical models to calculate the influence area of the disturbance waves and use wave makers to generate reverse waves to offset the disturbance waves. This method relies on the pre-analysis of the disturbance waves generated by the vibration table, and usually there is no accurate wave prediction, and it is also impossible to adjust the waveform in real time.

[0004] Most of the existing technologies rely on post-reaction to the disturbance waves, and lack accurate prediction and active control ability of the disturbance waves. The wave surface of the disturbance waves generated by the vibration table cannot be accurately predicted, so it is impossible to achieve real-time and accurate absorption of the disturbance waves. SUMMARY

[0005] Therefore, the present application provides an underwater vibration table disturbance wave active elimination method and device based on potential flow theory, which solves the problem that the existing underwater vibration table disturbance wave elimination method cannot absorb the disturbance waves in real time and accurately.

[0006] To achieve the above purpose, the present scheme is as follows:

[0007] An underwater vibration table disturbance wave active elimination method based on potential flow theory, comprising:

[0008] According to the motion time history of the vibration table and the physical characteristics of the pool, the waveform information of the disturbance waves is calculated;

[0009] The propagation distance between the wave plate and the underwater vibration table is obtained;

[0010] calculating the propagation speed of the disturbance wave;

[0011] calculating the target time when the disturbance wave propagates to the wave board based on the propagation speed and the propagation distance;

[0012] at the target time, starting the wave maker and controlling the displacement of the wave maker push plate in real time according to the wave form information to generate a wave surface opposite to the disturbance wave.

[0013] Preferably, the calculation formula of the wave form information is:

[0014]

[0015] wherein U is the maximum speed of the vibration table, ω is the angular frequency of the vibration table, k, k n is the wave number, b is the half table length of the vibration table, h is the water depth, x is the position of the disturbance wave, and t is the propagation time of the disturbance wave.

[0016] Preferably, the calculation formula of the propagation speed is:

[0017]

[0018] wherein c is the propagation speed, g is the gravitational acceleration, and k is the wave number.

[0019] Preferably, the calculation formula of the target time is:

[0020]

[0021] wherein r1 is the target time, l is the propagation distance, and c is the propagation speed.

[0022] Preferably, the formula for calculating the displacement of the wave maker push plate according to the wave form information is:

[0023]

[0024] wherein X a is the push plate displacement, X a (t) is the push plate displacement at different propagation times t, M is the transfer function of the wave maker, and η zdj (x, t) is the wave form information of the disturbance wave.

[0025] An underwater vibration table disturbance wave active elimination device based on potential flow theory, comprising:

[0026] a wave surface calculation unit configured to calculate wave form information of a disturbance wave based on a motion time history of a vibration table and physical characteristics of a water pool;

[0027] A propagation distance acquisition unit is configured to acquire a propagation distance between the wave board and the underwater vibration table.

[0028] A speed calculation unit is configured to calculate a propagation speed of the disturbance wave.

[0029] A time calculation unit is configured to calculate a target time when the disturbance wave propagates to the wave board based on the propagation speed and the propagation distance.

[0030] A control unit is configured to start the wave generator at the target time, and control displacement of a push plate of the wave generator in real time according to the wave form information, so as to generate a wave surface opposite to the disturbance wave.

[0031] According to the embodiments of the present application, the following technical effects are provided.

[0032] The underwater vibration table disturbance wave active elimination method based on the potential flow theory provided by the present application comprises the following steps: calculating wave form information of a disturbance wave according to a motion time history of a vibration table and physical characteristics of a pool; acquiring a propagation distance between a wave board and the underwater vibration table; calculating a propagation speed of the disturbance wave; calculating a target time when the disturbance wave propagates to the wave board based on the propagation speed and the propagation distance; and starting the wave generator at the target time, and controlling displacement of a push plate of the wave generator in real time according to the wave form information, so as to generate a wave surface opposite to the disturbance wave. The wave surface equation of the underwater vibration table disturbance wave is derived based on the potential flow theory, so that the propagation speed of the disturbance wave and the time when the disturbance wave reaches a target area can be accurately predicted. The displacement of the push plate of the wave generator is accurately controlled in real time according to the wave form information of the disturbance wave, so that a wave form opposite to the disturbance wave is generated for active absorption. The disturbance wave is eliminated in real time, and the elimination strategy can be adjusted according to the dynamic change of the disturbance wave in the pool. BRIEF DESCRIPTION OF DRAWINGS

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are only embodiments of the present application, and other drawings can be obtained by those skilled in the art without any creative effort on the basis of the provided drawings.

[0034] Figure 1 A flow chart of the underwater vibration table disturbance wave active elimination method based on the potential flow theory provided by the present application is provided.

[0035] Figure 2 A flow chart of another underwater vibration table disturbance wave active elimination method based on the potential flow theory provided by the present application is provided.

[0036] Figure 3 A principle diagram of the underwater vibration table disturbance wave active elimination method based on the potential flow theory provided by the present application is provided.

[0037] Figure 4 A structure diagram of an underwater vibration table disturbance wave active elimination device based on potential flow theory is provided for an embodiment of the present application. DETAILED DESCRIPTION

[0038] The technical solutions in the embodiments of the present application will be clearly and completely described with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative labor fall within the protection scope of the present application.

[0039] First, the vibration table and the wave pool are introduced in combination with Figures 1-2 The method for actively eliminating disturbance waves of an underwater vibration table based on potential flow theory provided by the embodiments of the present application is introduced as follows. Figure 1 As shown in the method, the method comprises the following steps.

[0040] In step S01, the wave shape information of the disturbance wave is calculated according to the motion time history of the vibration table and the physical characteristics of the wave pool.

[0041] Specifically, the wave shape information of the disturbance wave is calculated by the derived disturbance wave surface equation according to the motion time history of the vibration table and the physical characteristics of the wave pool. The calculation formula of the disturbance wave surface is as follows.

[0042]

[0043] Wherein, U is the maximum speed of the vibration table, ω is the angular frequency of the vibration table, k, k n is the wave number, which is used to describe the propagation characteristics of the wave, b is the half-table length of the vibration table, h is the water depth, x is the position of the disturbance wave, and t is the propagation time of the disturbance wave.

[0044] The wave height information of the disturbance wave at different propagation positions x and propagation times t can be obtained by the calculation formula of the disturbance wave surface.

[0045] In step S02, the propagation distance between the wave maker and the underwater vibration table is obtained.

[0046] Specifically, after the calculation of the disturbance wave surface, the position of the wave maker needs to be determined. The position of the wave maker is a key factor affecting the absorption effect of the disturbance wave, and the distance between the wave maker and the vibration table is usually set to ensure the maximum efficiency of wave absorption. The distance between the wave maker and the vibration table can be adjusted according to the specific requirements of the experimental site. As shown in the figure, Figure 3 The distance between the wave maker 2 and the vibration table 1 is l.

[0047] In step S03, the propagation speed of the disturbance wave is calculated.

[0048] Specifically, the propagation speed of the disturbance wave is a key parameter affecting its propagation process. The wave speed can be calculated using the following formula:

[0049]

[0050] Where c is the propagation speed, g is the gravitational acceleration, and k is the wave number.

[0051] Step S04: Calculate the target time when the disturbance wave propagates to the wave-generating plate based on the propagation speed and propagation distance.

[0052] Specifically, based on the propagation speed of the disturbance wave, the time it takes for the disturbance wave to travel from the vibration table to the wave-generating plate is calculated to determine the start-up timing (target time) of the wave generator. This ensures the wave generator can start at the target time, thereby accurately generating a reverse wave to eliminate the disturbance wave. The formula for calculating the target time is:

[0053]

[0054] Where t1 is the target time, l is the propagation distance, and c is the propagation speed.

[0055] Step S05: At the target time, start the wave generator and control the displacement of the wave generator push plate in real time according to the waveform information to generate a wave surface opposite to the disturbance wave.

[0056] Specifically, based on the calculated target time t1, the wave generator is activated at the target time. The displacement of the wave generator's pusher plate is controlled in real time based on waveform information to generate waves opposite to the disturbance wave, thereby achieving active wave absorption. For example... Figure 3 As shown, based on the waveform information η zdj (x, t) represents the displacement X of the push plate. a .

[0057] The formula for calculating the displacement of the wave generator pusher plate based on waveform information is as follows:

[0058]

[0059] Among them, X a For the displacement of the push plate, X a (t) represents the pusher displacement at different propagation times t, M is the transfer function of the wave generator, representing the relationship between the pusher displacement and the wave surface, and η zdj (x, t) represents the waveform information of the interference wave.

[0060] This invention proposes a method for eliminating disturbance waves from an underwater shaking table based on active wave absorption control. First, by analyzing the shaking table's vibration time history and the physical characteristics of the water tank, the wave surface equation for the disturbance wave is derived using potential flow theory. This equation can accurately calculate the wave height of the disturbance wave generated by the underwater shaking table in the water tank. The calculation formula for the disturbance wave considers parameters such as the shaking table's amplitude, frequency, and wave velocity, thus providing accurate wave surface data for subsequent control. Next, by determining the position of the wave generator and the propagation speed of the disturbance wave in the water tank, the time it takes for the disturbance wave to propagate from the shaking table to the wave generator is calculated. This propagation time calculation is based on the wave velocity and the distance from the shaking table to the wave generator, ensuring precise timing of wave propagation.

[0061] After determining the propagation time, the wave generator will be activated at the target time. Based on the known waveform of the disturbance wave, the pusher displacement of the wave generator is adjusted in real time to generate a wave opposite to the disturbance wave, thereby achieving active absorption of the disturbance wave. The pusher displacement is calculated based on the wave surface information of the disturbance wave and the transfer function of the wave generator, ensuring that the generated reverse wave cancels out the disturbance wave. Furthermore, the operating state of the wave generator is adjusted in real time based on the dynamic changes of the disturbance wave and feedback information to further improve the wave attenuation effect. This invention can accurately and efficiently eliminate disturbance waves generated by underwater shaking tables, improving the stability of experimental equipment in the water tank and the accuracy of experimental results.

[0062] The active elimination device for underwater vibration table disturbance waves based on potential flow theory provided in the embodiments of the present invention will be described below. The active elimination device for underwater vibration table disturbance waves based on potential flow theory described below can be referred to in correspondence with the active elimination method for underwater vibration table disturbance waves based on potential flow theory described above.

[0063] First, combine Figure 4 This paper introduces an active device for eliminating disturbance waves from underwater shaking tables based on potential flow theory, such as... Figure 4 As shown, the underwater vibration table disturbance wave active cancellation device based on potential flow theory may include:

[0064] The wavefront calculation unit 100 is used to calculate the waveform information of the disturbance wave based on the motion time history of the shaking table and the physical characteristics of the water tank.

[0065] The propagation distance acquisition unit 200 is used to acquire the propagation distance between the wave-making plate and the underwater vibration table;

[0066] The velocity calculation unit 300 is used to calculate the propagation velocity of the disturbance wave;

[0067] The time calculation unit 400 is used to calculate the target time when the disturbance wave propagates to the wave-generating plate based on the propagation speed and propagation distance.

[0068] The control unit 500 is configured to start the wave generator at the target time and control the displacement of the push plate of the wave generator in real time according to the wave information, so as to generate a wave surface opposite to the disturbance wave.

[0069] Finally, it should be noted that the terminology used herein, such as first and second, is merely used to differentiate one entity or operation from another entity or operation, and does not necessarily require or imply any such actual relationship or order between the entities or operations. Moreover, the terms "comprising", "including", or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, article, or apparatus including a series of elements includes not only those elements, but also other elements not explicitly listed, or other elements inherent in such a process, method, article, or apparatus. Without more limitations, the element defined by the statement "comprising a" does not exclude the presence of additional identical elements in the process, method, article, or apparatus including the element.

[0070] The various embodiments in the specification are described in a progressive manner, and each embodiment focuses on the difference from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0071] The above description of the disclosed embodiments enables those skilled in the art to carry out or use the present application. Various modifications to the embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for actively eliminating disturbance waves of an underwater shaking table based on potential flow theory, characterized in that, The application relates to a wave generation method and device. Waveform information of the disturbance wave is calculated according to a motion time course of the vibration table and physical characteristics of the pool; A propagation distance between the wave board and the underwater vibration table is obtained; A propagation speed of the disturbance wave is calculated; A target time when the disturbance wave propagates to the wave board is calculated based on the propagation speed and the propagation distance; At the target time, the wave generator is started, and displacement of a push plate of the wave generator is controlled in real time according to the waveform information, so that a wave surface opposite to the disturbance wave is generated.

2. The method of claim 1, wherein, The calculation formula of the waveform information is: where U is the maximum velocity of the shaker, ω is the angular frequency of the shaker, k, k n is the wave number used to describe the propagation characteristics of the wave, b is the half-table length of the shaker, h is the water depth, x is the position of the interference wave, and t is the propagation time of the interference wave.

3. The method of claim 1, wherein, The calculation formula of the propagation speed is: Wherein, c is the propagation speed, g is the gravity acceleration, and k is the wave number.

4. The method of claim 1, wherein, The calculation formula of the target time is: Wherein, t1 is the target time, l is the propagation distance, and c is the propagation speed.

5. The method of claim 1, wherein, The formula for calculating the displacement of the push plate of the wave generator according to the waveform information is: where X a is the plate displacement, X a (t) is the plate displacement at different propagation times t, M is the transfer function of the wave maker, η zdj (x, t) is the wave form information of the disturbance wave.

6. An active elimination device of disturbance wave based on potential flow theory of underwater vibration table, characterized in that, The application relates to a wave generation method and device. A wave surface calculation unit is used for calculating waveform information of the disturbance wave according to a motion time course of the vibration table and physical characteristics of the pool; A propagation distance obtaining unit is used for obtaining a propagation distance between the wave board and the underwater vibration table; A speed calculation unit is used for calculating a propagation speed of the disturbance wave; A time calculation unit is used for calculating a target time when the disturbance wave propagates to the wave board based on the propagation speed and the propagation distance; A control unit is used for starting the wave generator at the target time, and controlling displacement of a push plate of the wave generator in real time according to the waveform information, so that a wave surface opposite to the disturbance wave is generated.

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