Equivalent test method and device for impact of sloshing liquid on large structure

Abstract

The invention belongs to the technical field of fluid tests, and particularly discloses an equivalent test method and device for impact of sloshing liquid on a large structure, and the method comprises the steps: storing liquid in an energy storage pool, and lifting for energy storage; the released liquid is flushed into a wave making pool to form waves; the impact mode is adjusted by controlling the water flow direction of the wave pool, including advancing wave impact formed by water flow in the same direction and hydraulic jump air wrapping impact formed by water flow in the reverse direction; the test model is tested by using different impact modes, and the impact effect of sloshing liquid on the large structure is simulated. The device comprises an energy storage pool, a wave making pool, a wave pool and a test model. According to the method, the complex liquid impact working condition can be effectively reproduced, the test can be carried out under a real scale or a large scale, and the problem of a scale effect of a traditional model test is solved. The method is easy and convenient to operate and low in cost, the sloshing impact characteristic can be accurately simulated, multiphase flow impact can be achieved, and a more reliable test means is provided for large-scale structure design.

Description

Technical Field

[0001] The present invention relates to the field of fluid testing technology, and in particular to an equivalent testing method and device for sloshing liquid impacting a large structure. Background Art

[0002] During liquid cargo transportation, liquid sloshing within tanks is a common and significant physical phenomenon. The impact loads generated by severe sloshing can trigger local structural failures, leading to bulkhead damage or other safety incidents. To assess the dynamic response of large structures to sloshing liquid, the industry typically relies on testing to obtain reliable data. However, due to the large size, high structural flexibility, and economic costs of liquid cargo tanks, full-scale sloshing tests are difficult to conduct.

[0003] The current mainstream research methods include three categories: scaled sloshing model tests, wave tank impact tests, and drop-water impact tests. Among them, the scaled sloshing model test is closest to the full-scale sloshing in terms of mechanism, but due to the influence of the scale ratio, some key physical processes (such as bubble entrainment and wall slamming) are difficult to reproduce accurately, and there is uncertainty in the conversion of test results to prototype structures. The wave tank impact test approximates the impact of sloshing liquid by generating traveling waves, but the wave-making system is complex, energy-intensive, and it is difficult to repeatedly generate specific waveforms; long-term operation will also cause fatigue damage to the test model and equipment. The drop-water impact test lifts the structural model to a certain height and then releases it to impact the static liquid surface. This method is simple to operate and has good repeatability, but its impact mechanism is significantly different from the actual action process of sloshing liquid, especially it cannot reproduce the multiphase flow impact formed by liquid-entrained gas.

[0004] Furthermore, while existing approaches to simulating liquid sloshing through jet impacts have emerged (e.g., Patent Publication No. CN113758673A discloses an experimental device for wave-flow impacting shore structures), the actual modes of action of jet impacts differ fundamentally from those of sloshing liquids, and the achievable impact types are limited, making it difficult to cover the two typical impact conditions commonly found in sloshing: traveling wave impact and entrained air impact. Therefore, a new method is urgently needed that can accurately replicate the various impact modes of sloshing liquids at a larger scale while balancing experimental cost and repeatability. Summary of the Invention

[0005] The purpose of the present invention is to provide an equivalent test method and device for sloshing liquid impacting a large structure, so as to solve the above-mentioned technical problems existing in the prior art.

[0006] To achieve the above objectives, in one aspect, the present invention provides an equivalent test method for sloshing liquid impacting a large structure, comprising:

[0007] Step S1, storing liquid in a storage tank, and accumulating gravitational potential energy by lifting the liquid;

[0008] Step S2: releasing the liquid to flush into the wave pool, forming waves that propagate toward the wave pool;

[0009] Step S3, adjusting the wave impact mode by controlling the water flow direction in the wave pool; wherein the wave impact mode includes: the same direction water flow assists in forming a traveling wave impact, and the reverse direction water flow assists in forming a hydraulic jump and air-entrained impact;

[0010] Step S4: using the wave impact pattern to set up a test model in a wave pool to simulate the impact effect of sloshing liquid on a large structure.

[0011] Furthermore, the method of lifting the liquid in step S1 includes: adjusting the cross-sectional shape and center of gravity height of the liquid in the energy storage tank by driving a movable gate through a hydraulic cylinder, and / or adjusting the overall height of the energy storage tank through a lifting mechanism to increase potential energy.

[0012] Furthermore, the liquid level of the wave-making pool in step S2 is controlled by a water storage dam provided at the edge of the wave-making pool, and the cross-section of the water storage dam is semicircular to prevent the jet from interfering with wave formation.

[0013] Furthermore, the control of the water flow direction in step S3 is achieved by multiple water pump groups, including:

[0014] When the first water pump group is turned on, the water flows in the same direction as the waves, maintaining the traveling wave shape;

[0015] When the second water pump group is turned on, the water flows in the opposite direction of the waves, causing the waves to roll and entrain air.

[0016] Furthermore, in step S4, the initial distance between the test model and the liquid surface of the wave pool must satisfy:

[0017] When there are no waves, the test model has no contact with the liquid surface;

[0018] When there are waves, it can form a stable impact, and the liquid level is less than 75% of the height of the water storage embankment.

[0019] On the other hand, the present invention further provides an equivalent test device for sloshing liquid impacting a large structure, which is used to implement the equivalent test method for sloshing liquid impacting a large structure as described in any of the above claims, comprising:

[0020] A storage tank with rotating gates, sliding gates and hydraulic cylinders for storing and releasing liquid;

[0021] A wave-making pool is connected to the energy storage pool, and a semicircular water storage dam is provided on one edge away from the energy storage pool;

[0022] A wave pool, with wave-breaking dikes provided on the sides adjacent to and away from the wave-making pool, and a first water pump group and a second water pump group connected to the bottom of the pool;

[0023] The test model is set in a wave pool to receive wave impact.

[0024] Furthermore, the energy storage tank is arranged on a lifting platform, and a lifting mechanism is provided at the bottom of the lifting platform.

[0025] Furthermore, an adjustable slope surface is provided at the connection point between the wave-making pool and the energy storage pool.

[0026] Furthermore, the bottom surface of the energy storage tank is a horizontal plane or an inclined plane with the same inclination angle as the adjustable slope surface.

[0027] Furthermore, the device of the present invention also includes a liquid circulation system, and the liquid circulation system includes:

[0028] The third water pump group is used to pump the liquid in the wave pool back to the wave-making pool;

[0029] The fourth water pump group is used to pump the liquid in the wave pool back to the energy storage tank.

[0030] This paper proposes a novel test method for equivalent sloshing liquid impacting large structures, effectively resolving the technical difficulties in conducting sloshing tests on actual ships. Compared with traditional test methods, this method has at least the following technical advantages:

[0031] 1. Scale advantage: Compared with the tank sloshing model test, the test can be carried out at full scale or large scale conditions, which greatly reduces the impact of scale ratio on the test results. The obtained data can be directly used for the optimization design of the structure.

[0032] 2. Ease of Operation: Compared to wave tank impact testing, this method is simpler to implement, less expensive, and offers greater precision in controlling liquid impact and greater site adaptability. By generating the target wave in one go, it avoids the overlapping process of traditional push-plate / rock-plate wave generation, improving test efficiency while reducing the contact time between the test instrument and the liquid.

[0033] 3. Simulation authenticity: Compared with the water drop impact test, this method can more accurately simulate the impact characteristics of sloshing liquid and realize multiphase flow impact modes such as air-entrained impact, thereby providing a more comprehensive equivalent simulation effect.

[0034] This method has demonstrated significant technological progress in test accuracy, operational efficiency, and simulation authenticity, providing a new solution for liquid impact testing of large structures. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0036] Figure 1 It is a structural schematic diagram of the test device of the present invention;

[0037] Figure 2 Schematic diagram of the traveling wave formation process of the test device of the present invention;

[0038] Figure 3 Schematic diagram of the hydraulic jump and air-entrained impact formation process of the test device of the present invention;

[0039] Figure 4 and Figure 5 Schematic diagram of the liquid potential energy adjustment process of the test device of the present invention;

[0040] In the figure: 1. Test model; 2. Rotating gate; 3. Adjustable slope surface; 4. Hydraulic cylinder; 5. Moving gate; 6. Lifting mechanism; 7. Water storage dike; 8. Wave-breaking dike; 9. First water pump group; 10. Second water pump group; 11. Third water pump group; 12. Fourth water pump group; 101. Energy storage tank; 102. Wave-making tank; 103. Wave tank; 104. Air entrainment area. DETAILED DESCRIPTION

[0041] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0042] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0043] Reference Figure 1 As shown, this embodiment provides an equivalent test method for sloshing liquid impacting a large structure, comprising:

[0044] Step S1: Store liquid in the energy storage tank 101 and accumulate gravitational potential energy by lifting the liquid.

[0045] Specifically, if Figure 1As shown, liquid is stored in a reservoir 101, where potential energy is accumulated by lifting the liquid. In one embodiment, opening the rotary gate 2 releases the liquid, converting the potential energy into kinetic energy. The liquid then flows from the reservoir 101 into the wave-generating pool 102. The reservoir 101, which accumulates and releases liquid, includes a rotary gate 2, a movable gate 5, and a hydraulic cylinder 4. The wave-generating pool 102, which is composed of a water storage dam 7 and an adjustable slope 3, is located on the outlet side of the rotary gate 2.

[0046] Step S2: releasing the liquid to rush into the wave pool 102 to form waves that propagate toward the wave pool 103.

[0047] Specifically, after being released, the lifted liquid falls along the adjustable slope 3 and rushes into the wave pool 102. The waves stirred up by the liquid rushing into the wave pool 102 propagate toward the water reservoir 7 and the wave pool 103. In one embodiment, the water in the wave pool 102 is at the same height as the water reservoir 7, ensuring that no unnecessary jets or slamming occur when the waves are formed.

[0048] The waves generated by the liquid rushing into the wave pool 102 propagate into the wave pool 103 and impact the test model 1, realizing an equivalent sloshing liquid impact process. The waves propagate in the wave pool 103 and are dissipated by the wave breakers 8 on both sides of the reservoir.

[0049] Step S3: adjusting the wave impact mode by controlling the water flow direction in the wave pool 103; wherein the wave impact mode includes: the same direction water flow assists in forming a traveling wave impact, and the reverse direction water flow assists in forming a hydraulic jump and air-entrained impact;

[0050] Specifically, two water pump groups are designed at the bottom of wave pool 103. When the first water pump group 9 is turned on, the water flow within the reservoir is in the same direction as the wave propagation. When the second water pump group 10 is turned on, the water flow within the reservoir is in the opposite direction of the wave propagation. The first water pump group 9 and the second water pump group 10 respectively achieve a traveling wave-like liquid impact equivalent to a sloshing liquid impact, and a liquid-encapsulated air impact similar to a hydraulic jump.

[0051] like Figure 2 As shown, when the first water pump unit 9 is turned on, the direction of water flow in the water reservoir is the same as the direction of wave propagation. When waves form and propagate in the wave pool 103, the water flow in the wave pool 103 does not cause the waves to roll over and minimizes energy loss during shallow water wave transmission, thereby ensuring the waveform of the traveling wave during propagation.

[0052] like Figure 3As shown, when the second water pump unit 10 is turned on, the direction of water flow in the reservoir is opposite to the direction of wave propagation. When waves form and propagate in the wave pool 103, the water flow in the wave pool 103 will increase the steepness of the wave front, causing the waves to roll over and water jump, thereby forming liquid-enclosed air impact.

[0053] Step S4: Using the wave impact pattern to set up the test model 1 in the wave pool 103 to simulate the impact effect of sloshing liquid on the large structure.

[0054] The test method of the present invention converts the potential energy of the accumulated liquid into kinetic energy when the liquid impacts. The liquid in the energy storage tank 101 is released and then rushes into the wave-generating tank 102 below, causing the water in the tank to overflow and form waves.

[0055] The present test method achieves different wave shapes by adjusting the cross-sectional shape and center-of-gravity height of the liquid in the reservoir 101. The shape of the reservoir 7 and the liquid level in the wave-generating tank 102 also influence the wave shape. To create traveling waves equivalent to the impact of sloshing liquid and avoid jet formation, the liquid level in the wave-generating tank 102 should be the same height as the reservoir 7, which should be semicircular.

[0056] In the present test method, the liquid level in wave pool 103 is lower than the height of water storage dam 7 and is 75% of the liquid level in wave pool 102. Test model 1 is positioned above the liquid level in wave pool 103. When there are no waves, test model 1 does not contact the liquid level in wave pool 103. The distance between test model 1 and water storage dam 7 must ensure that stable waves can be generated.

[0057] In the test method of the present invention, the water flow in the wave pool 103 flows in the same direction or in the opposite direction as the waves, and different test effects are achieved by controlling the relative flow directions of the water flow and the waves in the wave pool 103. Specifically:

[0058] Co-directional flow condition: When the water flow and the wave flow in the same direction, the water flow can assist in the formation of traveling waves. At this time, the water flow velocity should be lower than the wave propagation velocity.

[0059] Reverse flow condition: When the water flow and the wave flow in the opposite direction, the water flow can assist in forming the hydraulic jump and air impact phenomenon. At this time, the water flow velocity must be higher than the wave propagation velocity.

[0060] Flow rate control requirements:

[0061] The flow velocity and water depth settings must meet the following conditions: In calm conditions (i.e., when not interacting with waves), the Froude number (Fr) of the flow must satisfy Fr ≤ 1. The Froude number (Fr) is a crucial dimensionless parameter in fluid mechanics, characterizing the relative magnitude of a fluid's inertial force and gravity. When simulating flows with free surfaces (such as surface ship motion and open channel flow), the Froude number is an essential similarity criterion.

[0062] In the test method of the present invention, the bottom surface of the energy storage tank 101 can be a slope with the same inclination angle as the adjustable slope 3, or it can be a horizontal surface. The slope of the water storage dam 7 on the side of the wave-generating tank 102 can be a semicircular surface or other curved surface, but the slope of the water storage dam 7 near the top must be as small as possible.

[0063] It should be understood that, in practical applications, the above test method can be implemented by an equivalent test device for sloshing liquid impacting a large structure. Specifically, an embodiment of the present invention provides an equivalent test device for sloshing liquid impacting a large structure, such as Figures 1 to 5 As shown, the device includes a reservoir 101, a wave-generating pool 102, a wave pool 103, and a test model 1. The reservoir 101 is equipped with a rotating gate 2, a movable gate 5, and a hydraulic cylinder 4 for storing and releasing liquid. The wave-generating pool 102 is connected to the reservoir 101 and has a semicircular water-retention dike 7 on one side away from the reservoir 101. The wave pool 103 has a wave-breaking dike 8 on the side adjacent to and away from the wave-generating pool 102. The bottom of the pool is connected to a first water pump unit 9 and a second water pump unit 10. The test model 1 is placed in the wave pool 103 to receive wave impacts.

[0064] Through the above-described structure, the apparatus of this embodiment can achieve the common traveling wave and air-entrapped impacts found in sloshing impacts. Compared to full-scale ship tests, sloshing model tests, wave tank impact tests, and drop-overboard impact tests, the test method and apparatus of this embodiment can achieve various fluid impacts that are closer to sloshing liquid impacts at a lower cost and in accordance with test requirements. The impacts are easier to accurately control, and the test repeatability is high.

[0065] In a specific embodiment, Figure 1 As shown, an adjustable slope surface 3 is provided at the connection between the wave-making pool 102 and the energy storage pool 101. The bottom surface of the energy storage pool 101 is a horizontal surface or an inclined surface with the same inclination angle as the adjustable slope surface 3.

[0066] In a specific embodiment, Figure 1As shown, the apparatus of this embodiment also includes a liquid circulation system. Specifically, the liquid circulation system comprises a third water pump assembly 11 connecting the energized water reservoir 101 and the wave pool 102, and a fourth water pump assembly 12 connecting the energized water reservoir 101 and the wave pool 103. After the impact test is completed, the third water pump assembly 11 is activated to pump excess liquid from the wave pool 103 into the wave pool 102, ensuring that the liquid level in the wave pool 102 is flush with the water reservoir 7. The fourth water pump assembly 12 is activated to pump excess liquid from the wave pool 103 into the energized water reservoir 101. The third and fourth water pump assemblies 11, 12 enable the recycling of the test liquid.

[0067] In a specific embodiment, Figure 4 and Figure 5 As shown, by controlling the liquid mass, center of gravity height, and height of the energized water reservoir 101, accurate control of the liquid potential energy and wave kinetic energy in the energized water reservoir 101 can be achieved. The single liquid impact effect required for the test can be quickly and accurately generated.

[0068] In a specific embodiment, Figure 4 and Figure 5 As shown, the hydraulic cylinder 4 drives the movable gate 5 to adjust the center of gravity of the liquid in the accumulator tank 101, so that the cross-sectional shape and center of gravity of the liquid in the accumulator tank 101 can be ensured at different water storage capacities to control the waveform of the waves.

[0069] In a specific embodiment, Figure 4 and Figure 5 As shown, the energized water tank 101 is arranged on a lifting platform, and a lifting mechanism 6 is provided at the bottom of the lifting platform. In this embodiment, the lifting mechanism 6 is a cross-type lifting device. The cross-type lifting device cooperates with the adjustable slope surface 3 to achieve the height change of the energized water tank 101, thereby ensuring that the potential energy of the liquid in the energized water tank 101 is increased without changing the cross-sectional shape of the liquid.

[0070] The embodiment of the present invention completes the "potential energy-kinetic energy-wave" process in one go within the same device through the continuous layout of the energy storage tank 101, the wave-making tank 102, and the wave pool 103. The energy storage tank 101 first lifts and shapes the liquid in coordination with the lifting mechanism 6 and the hydraulic cylinder 4, and the magnitude and distribution of the gravitational potential energy can be precisely set. After the rotary gate 2 is instantly opened, the liquid pours into the wave-making tank 102 along the adjustable slope surface 3. The slope inclination and the gate opening jointly determine the initial flow velocity and flow rate, and thus directly determine the amplitude and period of subsequent waves. This avoids the complex drive mechanism and long equipment operation required for traditional push-plate or rock-plate wave generation. A semicircular water storage dike 7 at the outlet of the wave pool 102 eliminates jets and secondary slams, ensuring pure wave propagation to the wave pool 103. Two groups of water pumps inject water in either the same or opposite directions. The former, when running at the same speed as the waves, forms stable traveling waves, while the latter, when operating against the current, increases wave steepness and induces a water jump and rollover, resulting in the emergence of an air-entrained region 104. This naturally achieves two typical modes of sloshing impact within the same apparatus. Test model 1 remains above the liquid surface, unaffected by still water buoyancy when waves are still, but impacted by precisely designed wave heights when waves are present. Wave-breaking dike 8 promptly absorbs reflected waves, ensuring consistent boundary conditions for each test. After the test is complete, the third and fourth water pump groups 12 return the water to the wave pool 102 and the energy storage pool 101, respectively, achieving a closed circulation of liquid within the apparatus. This not only conserves water resources but also allows the initial liquid level, potential energy, and waveform for the next test to be reset within minutes. The scale of the entire system is no longer restricted by the scale effect, and prototype or near-prototype scales can be used directly for testing. The resulting impact load can be used for structural optimization without conversion. The potential energy, gate action, slope angle and water pump flow are all adjustable mechanically or electronically, allowing wave parameters to be accurately reproduced, thereby ensuring high repeatability of test results while significantly reducing test energy consumption and site occupancy.

[0071] In the description of the present invention, it should be understood that the terms "longitudinal", "transverse", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0072] The embodiments described above are merely descriptions of preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Without departing from the spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by persons skilled in the art should fall within the scope of protection defined by the claims of the present invention.

Claims

1. An equivalent test method for sloshing liquid impacting a large structure, characterized in that: include: Step S1, storing liquid in an energy storage tank (101), and accumulating gravitational potential energy by lifting the liquid; Step S2, releasing the liquid to rush into the wave pool (102), forming waves that propagate toward the wave pool (103); Step S3, adjusting the wave impact mode by controlling the water flow direction in the wave pool (103); wherein the wave impact mode includes: the same direction water flow assists in forming the traveling wave impact, and the reverse direction water flow assists in forming the hydraulic jump air-entrained impact; Step S4: Using the wave impact pattern to set up a test model (1) in a wave pool (103) to simulate the impact effect of sloshing liquid on a large structure.

2. The equivalent test method for sloshing liquid impacting a large structure according to claim 1, characterized in that: The method of lifting the liquid in step S1 includes: driving the movable gate (5) by the hydraulic cylinder (4) to adjust the cross-sectional shape and the center of gravity height of the liquid in the energy storage tank (101), and / or adjusting the overall height of the energy storage tank (101) by the lifting mechanism (6) to increase the potential energy.

3. The equivalent test method for sloshing liquid impacting a large structure according to claim 1, characterized in that: In step S2, the liquid level of the wave-making pool (102) is controlled by a water storage dam (7) provided at the edge of the wave-making pool (102). The cross section of the water storage dam (7) is semicircular to prevent the jet from interfering with wave formation.

4. The equivalent test method for sloshing liquid impacting a large structure according to claim 1, characterized in that: The control of the water flow direction in step S3 is achieved by multiple water pump groups, including: When the first water pump group (9) is turned on, the water flows in the same direction as the waves, maintaining the traveling wave shape; When the second water pump group (10) is turned on, the water flows in the opposite direction to the waves, causing the waves to roll and entrain air.

5. The equivalent test method for sloshing liquid impacting a large structure according to claim 1, characterized in that: In step S4, the initial distance between the test model (1) and the liquid surface of the wave pool (103) must satisfy: When there are no waves, the test model (1) has no contact with the liquid surface; When there are waves, a stable impact can be formed, and the liquid level is less than 75% of the height of the water storage dam (7).

6. An equivalent test device for sloshing liquid impacting a large structure, used to implement the equivalent test method for sloshing liquid impacting a large structure according to any one of claims 1 to 5, characterized in that: include: An energy storage tank (101) is provided with a rotating gate (2), a movable gate (5) and a hydraulic cylinder (4) for storing and releasing liquid; A wave-making pool (102) is connected to the energy storage pool (101), and a semicircular water storage dam (7) is provided on the edge of one side away from the energy storage pool (101); The wave pool (103) is provided with a wave-breaking dike (8) on the sides adjacent to and away from the wave-generating pool (102), and the bottom of the pool is connected to a first water pump group (9) and a second water pump group (10); The test model (1) is arranged in a wave pool (103) and is used to receive wave impact.

7. The equivalent test device for sloshing liquid impacting a large structure according to claim 6, characterized in that: The energy storage water tank (101) is arranged on a lifting platform, and a lifting mechanism (6) is provided at the bottom of the lifting platform.

8. The equivalent test device for sloshing liquid impacting a large structure according to claim 7, characterized in that: An adjustable slope surface (3) is provided at the connection point between the wave-making pool (102) and the energy storage pool (101).

9. The equivalent test device for sloshing liquid impacting a large structure according to claim 8, characterized in that: The bottom surface of the energy storage water tank (101) is a horizontal surface or a slope having the same inclination angle as the adjustable slope surface (3).

10. The equivalent test device for sloshing liquid impacting a large structure according to claim 6, characterized in that: Also included is a liquid circulation system, the liquid circulation system comprising: a third water pump group (11), used for pumping liquid from the wave pool (103) back to the wave-generating pool (102); The fourth water pump group (12) is used to pump the liquid in the wave pool (103) back to the energy storage pool (101).

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