Super-gravity field wave simulation method

Abstract

The invention relates to the technical field of wave simulation generation, in particular to a high-gravity field wave simulation method. The high-gravity field wave simulation method comprises the following steps: in a high-gravity field, performing similarity rate verification on a high-gravity field wave making similarity relationship between a predetermined wave height and a frequency dimensionless quantity; under the condition that the similarity rate verification is consistent, calibrating parameters of the super-gravity field wave making similarity relationship; and according to the super-gravity field wave making similarity relationship of the calibration parameters, performing super-gravity field wave simulation. According to the invention, waves in different environments in a super-gravity field can be accurately simulated, a transfer function can be accurately constructed, and the influence of physical quantities such as different motion amplitudes, different frequencies and different gravitational accelerations on wave making can be accurately evaluated.

Description

Technical Field

[0001] The present invention relates to the technical field of wave simulation generation, and in particular to a method for simulating waves in a hypergravity field. Background Art

[0002] Hypergravity field wave simulation test facilities utilize the scaled-down effect to study the effects and damage mechanisms of waves on relevant structures, providing a simulation and verification platform for marine environmental research and the development and application of marine resources. These facilities are primarily used to generate waves of varying water depths, wave heights, and frequencies, and are a key component of these wave simulation test facilities. Current hypergravity field wave generators primarily utilize push-plate and rock-plate types. The movement and power mechanisms of these two types require a certain amount of horizontal space, reducing the effective wave generation range. Research on gravity-based wave generation in hypergravity fields is limited, and it is difficult to accurately simulate waves in different environments, accurately construct transfer functions, and accurately evaluate the effects of various motion amplitudes, frequencies, and gravitational accelerations on wave generation. Therefore, research is urgently needed on hypergravity-based wave simulation technology to develop methods for determining transfer functions, mapping mechanical motion to wave motion, ensuring wave consistency, and providing methods for selecting test parameters, thereby providing a standardized marine environmental test platform for marine engineering research.

[0003] The information in the background technology is only intended to illustrate the general background of the invention and should not be regarded as an admission or any form of suggestion that this information constitutes the prior art known to a person skilled in the art. Summary of the Invention

[0004] To solve at least some of the technical problems in the prior art, the present invention provides a method for simulating hypergravity field waves. Specifically, the present invention includes the following contents.

[0005] The present invention provides a method for simulating hypergravity field waves, the method comprising:

[0006] Under the hypergravity field, the similarity relationship between the pre-determined dimensionless quantities of wave height and frequency in the hypergravity field is verified by similarity ratio.

[0007] When the similarity ratios are verified to be consistent, the parameters of the similarity relationship of the hypergravity field wave generation are calibrated;

[0008] Based on the similarity relationship of hypergravity field wave generation with calibrated parameters, hypergravity field wave simulation is carried out.

[0009] Optionally, the similarity relationship of the hypergravity field wave generation is:

[0010]

[0011] Where H is the wave height, h is the liquid depth, f0 is the device motion frequency, S is the device amplitude, and ng is the gravitational acceleration.

[0012] Optionally, the hypergravity field wave simulation method further includes:

[0013] Based on the dimensionless terms, a dimensionless expression for the supergravity field wave height is established:

[0014]

[0015] Where R is the radius of the semi-cylinder, ρ w is the liquid density, ρ s is the material density of the semi-cylinder;

[0016] The hypergravity field wave-making similarity relationship is determined according to the dimensionless expression of the hypergravity field wave height.

[0017] Optionally, the dimensionless term includes:

[0018] Device amplitude to liquid depth ratio:

[0019]

[0020] Frequency dimensionless quantity:

[0021]

[0022] Ratio of device radius to liquid depth:

[0023]

[0024] Ratio of device density to water density:

[0025]

[0026] Optionally, the proportional factors and corresponding values ​​of various physical quantities of the hypergravity field wave simulation are determined based on the dimensionless expression of the hypergravity field wave height.

[0027] Optionally, the scale factors and corresponding values ​​of various physical quantities in the hypergravity field wave simulation are shown in the following table:

[0028]

[0029] Optionally, the similarity verification of the hypergravity field wave-generating similarity relationship between the predetermined wave height and frequency dimensionless quantities includes:

[0030] Based on the previously obtained hypergravity field gravity wave-making device, a series of wave-making verification tests were carried out under the same conditions;

[0031] According to the wave-making verification test, the proportional factors and corresponding values ​​of various physical quantities of the wave-making verification test are obtained;

[0032] According to the proportional factors and corresponding values ​​of various physical quantities of the wave-making verification test and the proportional factors and corresponding values ​​of various physical quantities of the hypergravity field wave simulation, the similarity relationship of the hypergravity field wave-making is verified by similarity rate.

[0033] Optionally, when the similarity verification is consistent, calibrating the parameters of the hypergravity field wave-making similarity relationship includes:

[0034] When the similarity is verified to be consistent, a wave-making calibration test is carried out under different scales according to the hypergravity field gravity wave-making device;

[0035] The parameters of the hypergravity field wave-making similarity relationship are calibrated based on the hypergravity field wave-making similarity relationship and data obtained from the wave-making calibration test.

[0036] Optionally, the hypergravity field wave simulation method further includes:

[0037] The previously obtained supergravity field gravity wave-making device is installed on the centrifuge, and the supergravity field is constructed through the centrifuge.

[0038] The present invention can accurately simulate waves in different environments under a hypergravity field, accurately construct transfer functions, and accurately evaluate the effects of physical quantities such as different motion amplitudes, different frequencies, and different gravitational accelerations on wave generation. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 A flow chart of a method for simulating hypergravity field waves provided in an embodiment of the present invention;

[0040] Figure 2 A detailed flow chart of the hypergravity field wave simulation method provided by an embodiment of the present invention;

[0041] Figure 3 A schematic structural diagram of a hypergravity field gravity wave-generating device provided in an embodiment of the present invention;

[0042] Figure 4 A schematic diagram of a centrifugal rotor provided in an embodiment of the present invention;

[0043] Figure 5 、 Figure 6 、 Figure 7 A schematic diagram of parameter calibration provided by an embodiment of the present invention;

[0044] Figure 8 This is a flow chart of a simulation test provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0045] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0046] It should be understood that the terms described in the present invention are only for describing particular embodiments and are not intended to limit the present invention. In addition, for numerical ranges in the present invention, it should be understood that the upper and lower limits of the ranges and each intermediate value therebetween are specifically disclosed. Each smaller range between any stated value or intermediate value within a stated range and any other stated value or intermediate value within the stated range is also included in the present invention. The upper and lower limits of these smaller ranges may be independently included or excluded within the scope.

[0047] Unless otherwise indicated, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the invention belongs. Although the present invention describes only preferred methods and materials, any methods and materials similar or equivalent to those described herein may also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials related to the documents. In the event of any conflict with any incorporated document, the content of this specification shall prevail.

[0048] Example 1

[0049] The embodiment of the present invention provides a method for simulating hypergravity field waves, such as Figure 1 As shown in Figure 2, the supergravity field wave simulation method includes:

[0050] S101, in a hypergravity field, verifying the similarity of the hypergravity field wave-making similarity relationship between the predetermined dimensionless quantities of wave height and frequency;

[0051] S102, when the similarity rates are verified to be consistent, calibrating the parameters of the hypergravity field wave-making similarity relationship;

[0052] S103, performing hypergravity field wave simulation based on the hypergravity field wave generation similarity relationship of the calibration parameters.

[0053] The embodiment of the present invention verifies the similarity of the hypergravity field wave-making similarity relationship between the predetermined wave height and frequency dimensionless quantities in the hypergravity field, and calibrates the parameters of the hypergravity field wave-making similarity relationship when the similarity verification is consistent. Then, based on the hypergravity field wave-making similarity relationship with the calibrated parameters, waves in different environments under the hypergravity field can be accurately simulated, a transfer function can be accurately constructed, and the influence of physical quantities such as different motion amplitudes, different frequencies, and different gravitational accelerations on wave making can be accurately evaluated.

[0054] In the embodiment of the present invention, a previously obtained hypergravity field gravity wave generator can be installed in a centrifugal rotor to construct a hypergravity field. The hypergravity field gravity wave generator can be obtained by pre-development.

[0055] like Figure 2 As shown, the embodiments of the present invention are described in detail below through device development and wave simulation.

[0056] 1. Device development process

[0057] 1. Basic unit selection

[0058] (1) Device structure:

[0059] In some embodiments, the provided hypergravity field gravity wave generating device is referred to as a device, such as Figure 3 As shown, it includes a model box, a wave-making unit, a wave-breaking unit, and a measuring unit.

[0060] The wave-making unit includes a power mechanism, a motion mechanism, connecting parts, and a guide rail; the power mechanism is used to provide power for wave generation, and includes a hydraulic cylinder and a servo valve. The motion mechanism is used to directly act on the liquid (water) in the model box and generate waves. The hydraulic cylinder and the motion mechanism of the power mechanism are connected together by connecting parts, and the motion mechanism is set on a directional guide rail. The connecting part can be a rod. The power mechanism, the rod, the motion mechanism and the guide rail constitute a combined transmission structure. The combined transmission structure is installed on one side of the model box. The motion mechanism is a hollow semi-cylindrical structure. The length of the semi-cylinder is consistent with the width of the model box. The semi-cylinder plane is in contact with the side of the model box and is directional moved by the guide rail. After the liquid is injected into the model box, the equilibrium position is adjusted to the position of the symmetry axis of the semi-cylindrical motion mechanism.

[0061] The hydraulic device of the power mechanism drives the hollow semi-cylinder to move up and down periodically. The length of the semi-cylinder is consistent with the width of the model box, and the plane of the semi-cylinder fits the side of the model box. It moves up and down in a directional manner through the guide rail, so that the liquid around the semi-cylinder moves along the length direction of the model box, thereby forming a regular wave load.

[0062] The wave-chopping unit consists of a support and multiple layers of vertical wave-chopping plates. To achieve optimal wave-chopping effectiveness, the vertical wave-chopping plates are porous and have varying porosities, with the porosity increasing towards the wave-generating unit. The wave-chopping unit is mounted on the other side of the model box via a support made of angle steel bolted to the front and rear of the model box. The multiple layers of vertical wave-chopping plates are secured to the support. The wave-chopping plates are vertical porous plates used for passive wave-chopping. Two layers are optional: one with larger porosity and the other with smaller porosity. The larger-pore vertical wave-chopping plates serve as the first layer, while the smaller-pore vertical wave-chopping plates serve as the second layer. Porous volcanic rock can be placed in the center of the wave-chopping plates to reduce wave and reflected wave energy through the pores, enhancing the wave-chopping effectiveness.

[0063] The measuring unit is used to measure the physical quantity parameters of the preset wave load. The physical quantity parameters of the wave load include at least wave frequency, wave height, wavelength and wave velocity. The measuring unit includes a camera component, a wave height meter and a pore pressure sensor; the camera component includes a camera component for a top-view setting and a camera component for a side-view (or main-view) setting. The camera component for the side-view setting is a high-speed camera, which is used to obtain wave motion data in the model box based on the main-view perspective; the high-speed camera is placed on a bracket, facing the middle of the model box, and the lens is close to the glass observation window of the model box.

[0064] The overhead camera component obtains wave motion data in the model box based on the overhead perspective and observes the wave motion in the model box; it is placed on the top of the model box and fixed to the rear wall by a bracket and bolts.

[0065] Ultrasonic and contact level gauges are used to accurately measure and visually display the water level inside the model tank. The wave height gauge is fixed to a crossbeam that runs the length of the model tank, with one end bolted to the tank wall.

[0066] The pore pressure sensor is used to measure the liquid pressure inside the model box and is set at the bottom of the model box.

[0067] The wave height meter and pore pressure sensor are used to detect wave motion data at one or more points, respectively. Wave motion data at a single point is used to determine wave height and frequency, while data from multiple points is used to determine wavelength and velocity. The camera component captures image data of wave loads, which are used to determine wave frequency, height, wavelength, and velocity. The data generated by the wave height meter, pore pressure sensor, and camera are calibrated to ensure accurate parameter determination. Physical parameters of wave loads can also include the device's motion frequency and velocity, which can be derived from the motion mechanism's displacement and maximum thrust curves.

[0068] The embodiment of the present invention realizes the connection between the wave-making unit, the clipping unit, the measuring unit and the model box through reasonable arrangement and structural design. Figure 4 As shown, the device is installed on a centrifuge rotor to achieve a supergravity field.

[0069] (2) Device selection

[0070] Because the semi-cylinder is subject to a large buoyancy in the water, which can offset most of its own weight, the hydraulic device makes the semi-cylinder move up and down in the equilibrium position, thereby generating periodic wave loads. When the hollow ratio of the semi-cylinder (the hollow ratio is defined as the ratio of the void to the total volume) is as follows, the equilibrium position is exactly at the symmetry axis of the semi-cylinder,

[0071]

[0072] Among them, ρ w is the liquid density, ρ s is the material density of the semi-cylinder. At this time, the maximum thrust F and the semi-cylinder stroke meet

[0073]

[0074] Where F is the maximum thrust, Δh is the maximum displacement of the semi-cylinder, W is the width of the model box, R is the radius of the semi-cylinder, and ng is the centrifugal acceleration. The device can be placed on a centrifugal rotor to conduct wave generation experiments.

[0075] The formula shows that the maximum thrust is related to the volume of the motion mechanism. For wedge-shaped and semi-cylindrical motion mechanisms with the same cross-sectional width and height, the semi-cylindrical motion mechanism can generate greater thrust and generate larger waves at the same stroke. The curved surface design reduces water flow separation and has higher energy transfer efficiency. The waves generated by the semi-cylindrical mechanism are smoother, have fewer secondary reflections, have stronger nonlinear characteristics, and are closer to natural waves. It is more suitable for centrifugal tests and can generate multi-directional waves.

[0076] Within the effective control range, different wave loads can be generated by adjusting the thrust, frequency, and centrifugal acceleration. In the hypergravity field, since the Mach number and Froude number both satisfy similar relationships, the resulting wave load attenuation law and the interaction between underwater explosion loads and wave loads under wave conditions will be similar to those of the prototype.

[0077] 2. Model assembly

[0078] Based on the basic units determined above, the model is assembled.

[0079] 3. Wave-making test

[0080] Based on the wave-making test data, the basic unit selection is revised.

[0081] 2. Hypergravity field wave test

[0082] 1. Confirmation of relevant physical quantities

[0083] Usually the wave height H and frequency f w , wavelength λ, wave speed v and other physical quantities are related to the following variables:

[0084] Wave-making parameters: device amplitude S, device motion frequency f0, semi-cylinder radius R, device density ρ s ;

[0085] Environmental parameters: liquid depth h, liquid density ρ w ;

[0086] Supergravity parameters: gravitational acceleration ng,

[0087] The expression of wave height H is:

[0088] H=f(S,f0,r,h,ρ w ,ρ s ,ng)

[0089] Among them, wave height, wave height and wave height are all expressed as the height of the waves.

[0090] 2. Dimensional analysis to determine the similarity relationship between hypergravity field wave generation

[0091] According to dimensional analysis, choose the liquid density ρ w , gravitational acceleration ng, and water depth h are repeated variables, and the dimensionless π term is constructed:

[0092] Device amplitude to liquid depth ratio:

[0093]

[0094] Frequency dimensionless quantity:

[0095]

[0096] Ratio of semi-cylinder radius to liquid depth:

[0097]

[0098] Ratio of device density to water density:

[0099]

[0100] Establish a dimensionless expression for wave height in the wave supergravity field

[0101]

[0102] Based on this formula, the proportional factors of various physical quantities in supergravity field wave simulation can be obtained.

[0103] Table 1 Hypergravity field scaling factors

[0104]

[0105]

[0106] For a specific liquid and a specific motion mechanism, π3 and π4 remain constant. The amplitude of the device is much smaller than the water depth, so π1 changes little and has little effect on the wave height. Therefore, the generated wave height is mainly related to π2. The above formula is simplified to

[0107]

[0108] 3. Similarity verification, i.e. verification of the similarity of supergravity field waves

[0109] To ensure the reliability of the test, the similarity of wave generation can be verified using the following methods. For the prototype, tests are conducted at different scales, adjusting the water depth, device size, and motion frequency based on the device similarity relationship. This verifies the similarity of wave heights at the prototype scale. Simultaneously, ground-based tests can be conducted to verify the impact of the hypergravity field on wave simulation.

[0110] (1) Transfer function calibration

[0111] First, a similarity verification study is conducted on the wave height, that is, a series of tests are carried out under the same conditions to determine whether the tests can return the same results. If the results are consistent, it will directly prove the establishment of the similarity relationship in the above table; for example, based on the supergravity field gravity wave-making device, a series of wave-making verification tests are carried out under the same conditions; based on the wave-making verification tests, the proportional factors and corresponding values ​​of each physical quantity of the wave-making verification test are obtained; based on the proportional factors and corresponding values ​​of each physical quantity of the wave-making verification test and the proportional factors and corresponding values ​​of each physical quantity of the supergravity field wave simulation, the similarity relationship of the supergravity field wave-making is verified by similarity. If the results are consistent, it will directly prove the establishment of the similarity relationship in the above table.

[0112] (2) Determine formula parameters and confirm transfer function

[0113] After verifying the correlation between wave height parameters and , the test was carried out under different conditions, such as Figure 5 As shown, a functional relationship between wave height and is obtained, and the parameters therein are calibrated. For example, if the similarity is verified to be consistent, wave-making calibration tests are conducted at different scales using the hypergravity field gravity wave-making device. Based on the hypergravity field wave-making similarity relationship and the data obtained from the wave-making calibration test, the parameters of the hypergravity field wave-making similarity relationship are calibrated.

[0114] 4. Hypergravity field wave-generating test

[0115] This involves designing a test plan, modeling a hypergravity field gravity wave generator, installing equipment such as a centrifuge, and then conducting ground tests. Equipment is then inspected and parameters adjusted based on the tests. If the results meet expectations, core calculations, cable connections, oil line connections, counterweight adjustment, hypergravity testing, and test completion are performed. A test model can be constructed based on the test plan, and the device can be protected and waterproofed. The effects of different motion amplitudes, frequencies, and gravitational accelerations on wave generation can be studied. Based on similarity theory, expressions for wave elements are established. For some resonant frequencies that cannot form a stable waveform, the gravitational acceleration can be adjusted and the simulation frequency can be changed. For stable waveforms, classification and identification can be performed, and transfer functions can be constructed. On the basis of stable wave generation, explosion tests can be added to simulate the effects of waves on the explosive load sequence in an ocean wave environment.

[0116] The hypergravity field wave simulation method of the embodiment of the present invention has achieved remarkable results in many aspects. It can accurately simulate waves in different environments under the hypergravity field, accurately construct transfer functions, and accurately evaluate the influence of physical quantities such as different motion amplitudes, different frequencies, and different gravitational accelerations on wave generation.

[0117] Although the present invention has been described with reference to exemplary embodiments, it should be understood that the invention is not limited to the disclosed exemplary embodiments. Various modifications and variations may be made to the exemplary embodiments of the present specification without departing from the scope or spirit of the present invention. The scope of the claims is to be given the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.

Claims

1. A method for simulating hypergravity field waves, characterized in that: The hypergravity field wave simulation method comprises: Under the hypergravity field, the similarity relationship between the pre-determined dimensionless quantities of wave height and frequency in the hypergravity field is verified by similarity ratio. When the similarity ratios are verified to be consistent, the parameters of the similarity relationship of the hypergravity field wave generation are calibrated; Based on the similarity relationship of hypergravity field wave generation with calibrated parameters, hypergravity field wave simulation is carried out.

2. The method for simulating hypergravity field waves according to claim 1, characterized in that: The similarity relationship of the supergravity field wave generation is: Where H is the wave height, h is the liquid depth in the device, f0 is the device motion frequency, S is the device amplitude, and ng is the gravitational acceleration.

3. The method for simulating hypergravity field waves according to claim 2, characterized in that: The hypergravity field wave simulation method further comprises: Based on the dimensionless terms, a dimensionless expression for the supergravity field wave height is established: Where R is the radius of the semi-cylinder, ρ w is the liquid density, ρ s is the material density of the semi-cylinder; The hypergravity field wave-making similarity relationship is determined according to the dimensionless expression of the hypergravity field wave height.

4. The method for simulating hypergravity field waves according to claim 3, characterized in that: The dimensionless terms include: Device amplitude to liquid depth ratio: Frequency dimensionless quantity: Ratio of device radius to liquid depth: Ratio of device density to water density:

5. The method for simulating hypergravity field waves according to claim 3, characterized in that: According to the dimensionless expression of the hypergravity field wave height, the proportional factors and corresponding values ​​of various physical quantities of the hypergravity field wave simulation are determined.

6. The method for simulating hypergravity field waves according to claim 5, characterized in that: The scale factors and corresponding values ​​of various physical quantities in the hypergravity field wave simulation are shown in the following table:

7. The method for simulating hypergravity field waves according to claim 5, characterized in that: The similarity verification of the hypergravity field wave-generating similarity relationship between the predetermined wave height and frequency dimensionless quantities includes: Based on the previously obtained hypergravity field gravity wave-making device, a series of wave-making verification tests were carried out under the same conditions; According to the wave-making verification test, the proportional factors and corresponding values ​​of various physical quantities of the wave-making verification test are obtained; According to the proportional factors and corresponding values ​​of various physical quantities of the wave-making verification test and the proportional factors and corresponding values ​​of various physical quantities of the hypergravity field wave simulation, the similarity relationship of the hypergravity field wave-making is verified by similarity rate.

8. The method for simulating hypergravity field waves according to claim 7, characterized in that: When the similarity rate verification is consistent, the parameters of the hypergravity field wave-making similarity relationship are calibrated, including: When the similarity is verified to be consistent, a wave-making calibration test is carried out at different scales based on the hypergravity field gravity wave-making device; The parameters of the hypergravity field wave-making similarity relationship are calibrated based on the hypergravity field wave-making similarity relationship and data obtained from the wave-making calibration test.

9. The method for simulating hypergravity field waves according to claim 1, characterized in that: The hypergravity field wave simulation method further comprises: The previously obtained supergravity field gravity wave-making device is installed on the centrifuge, and the supergravity field is constructed through the centrifuge.

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