A laboratory surface wave and multi-mode internal wave coupling generation device and method

Abstract

The present invention provides a laboratory surface wave and multi-modal internal wave coupling generation device, which includes a glass water tank, an automatic lifting platform, a wave maker, a wave-making block and a wave-breaking plate; the interior of the glass water tank is filled with water of different densities; the automatic lifting platform is matched and arranged on the upper part of one end of the glass water tank; the wave maker is matched and arranged on the automatic lifting platform and is lifted and lowered under the drive of the automatic lifting platform; the power output end of the wave maker is matched and installed with the wave-making block; the wave-making block is located on the inner side of the glass water tank; the wave-breaking plate is matched and arranged inside the other end of the glass water tank and forms an angle of 15-20° with the bottom of the glass water tank. The present invention is convenient for replacing the wave-making module and combining with changing the oscillation frequency to obtain surface waves of different wave heights and wavelengths, and can excite multi-modal internal waves at the inner interface to achieve the coupled generation of surface waves and multi-modal internal waves.

Description

Technical Field

[0001] The invention belongs to the technical field of ship and ocean engineering, and in particular relates to a device and method for generating laboratory surface wave and multi-mode internal wave coupling. Background Art

[0002] Ocean waves and internal waves are both common physical phenomena in the ocean, and the two are accompanied by energy exchange during the propagation process. Ocean internal waves are internal fluctuations in the ocean when the layered structure is destroyed by external disturbances in an ocean with a stable stratified structure. It is a wave phenomenon that almost runs through the entire depth of the ocean. And because the inter-layer variation of seawater density is very small, the reduced gravity is much smaller than gravity. Compared with the waves at the free surface, the seawater will produce ocean internal waves with huge amplitudes when it is slightly disturbed. For underwater vehicles, this kind of internal wave with huge amplitude will be accompanied by a drastic change in the density surface, and the resulting buoyancy fluctuations will have an important impact on the safe navigation of the vehicle. In addition, during the propagation of internal waves, in addition to the change in the density surface, reciprocating horizontal flows with strong vertical shear will also be generated, threatening the safety of marine structures. Ocean waves and internal waves are the two most important loads in the ocean, and they pose a serious threat to the safe operation of marine structures. For the field of shipbuilding and marine engineering, its research is of great significance.

[0003] The method of generating waves in the laboratory is mainly the mass source driven method. On one side of the pool, the periodic reciprocating motion of objects such as push plates and wave blocks generates waves that propagate unidirectionally to the other side of the pool. By adjusting the size of the mass source, the movement period, etc., waves of different wave heights and frequencies can be achieved in the pool. The generation of internal waves requires two necessary conditions, one is the ocean structure with stable density stratification, and the other is the existence of a disturbance source. In the laboratory, the current method for generating internal waves is mainly through the pumping plate method, using the so-called "gravity collapse method" to generate internal solitary waves. This method can achieve the generation of internal solitary waves of different amplitudes by adjusting the height difference (collapse height) of the fluid on the left and right sides of the pumping plate, but for fixed stratification conditions, only one mode of internal waves can be generated, and it is difficult to obtain multi-mode internal waves. At the same time, the above wave or internal wave generation methods all require the deployment of devices on one side of the pool. The two devices are in a competitive relationship in space and are difficult to generate at the same time. The surface waves and internal waves are studied in isolation, and the coupling mechanism between the two is unclear. Summary of the invention

[0004] In order to solve the problems existing in the above-mentioned background technology, the present invention proposes a laboratory surface wave and multi-modal internal wave coupling generation device and method, which is easy to replace the wave-making module and combine with changing the oscillation frequency to obtain surface waves with different wave heights and wavelengths, and can excite multi-modal internal waves at the inner interface to achieve the coupled generation of surface waves and multi-modal internal waves.

[0005] In order to solve the above technical problems, the present invention provides a laboratory surface wave and multi-modal internal wave coupling generation device, which includes a glass water tank, an automatic lifting platform, a wave maker, a wave-making block and a wave-breaking plate; the interior of the glass water tank is filled with water of different densities; the automatic lifting platform is matched and arranged at the upper part of one end of the glass water tank; the wave maker is matched and arranged on the automatic lifting platform and is lifted and lowered under the drive of the automatic lifting platform; the power output end of the wave maker is matched and installed with the wave-making block; the wave-making block is located on the inner side of the glass water tank; the wave-breaking plate is matched and arranged inside the other end of the glass water tank and forms an angle of 15-20° with the bottom of the glass water tank.

[0006] The laboratory surface wave and multi-mode internal wave coupling generation device, wherein: the glass water tank includes a water tank body and a support; the water tank body has an accommodating space inside and is filled with water of different densities; the water tank body is placed on the ground through a plurality of supports vertically fixed on the outer walls at both ends thereof.

[0007] The laboratory surface wave and multi-modal internal wave coupling generation device, wherein: the automatic lifting platform adopts a scissor-type electric lifting platform, which is matched and arranged at one end of the water tank body and includes a base, a guide rail, a stepping motor, a transmission mechanism, a lifting frame and a table top; the base is matched and fixed to the upper part of one end of the water tank body; the guide rail is matched and horizontally fixed to the upper part of the base; the stepping motor is matched and arranged on the outside of one end of the base, and its power output end extends horizontally to the top of the base; the transmission mechanism is composed of a screw and a screw seat; one end of the screw is matched and fixedly connected to the power output end of the stepping motor, and the other end is matched and hinged with a bearing seat; the bearing seat is matched and fixed on the guide rail. The base is on one side of the end of the rail travel; the screw seat is slidably installed on the guide rail and is connected to the screw by threaded cooperation, and the screw seat is linearly displaced along the guide rail under the drive of the screw; the lifting frame includes a pair of support arms; the middle sections of a pair of support arms are matched and hinged to each other through hinge shafts; the lower end of one of the support arms is matched and hinged with the screw seat, and the lower end of the other support arm is matched and hinged with a support; the support is matched and fixed to the upper part of the other end of the base; the table top is matched and horizontally installed on the upper ends of a pair of support arms, and the bottom of one end is matched and hinged with the upper end of one of the support arms, and the bottom of the other end is matched and hinged with the upper end of the other support arm.

[0008] The laboratory surface wave and multi-modal internal wave coupling generation device, wherein: the wave maker is matched and arranged on the table, and includes a servo motor and a crank connecting rod; the servo motor is arranged on the table, and its power output end is matched and connected to one end of the crank connecting rod; the other end of the crank connecting rod extends vertically downward into the interior of the water tank body.

[0009] The laboratory surface wave and multi-modal internal wave coupling generation device, wherein: the wave-making block is matched and installed on the other end of the crank connecting rod; the rotation of the servo motor is converted into the linear reciprocating motion of the wave-making block through the crank connecting rod; the servo motor can continuously change the wave-making frequency by changing its rotation speed, and the oscillation stroke of the wave-making block can be achieved by changing the length of the connecting rod in the crank connecting rod.

[0010] A method for generating laboratory surface waves and multi-mode internal waves by coupling is based on the above-mentioned laboratory surface waves and multi-mode internal waves coupling generating device, which specifically comprises the following steps:

[0011] (1) Configure the upper and lower layers of density-stratified water according to the size of the glass water tank, and strictly control the layer depth ratio;

[0012] (2) According to the size of the glass water tank and the oscillation stroke of the wave maker, the extreme position of the wave maker is adjusted so that the lowest position of the wave maker is located above the two layers of density water stratification and the highest position of the wave maker is located below the surface of the upper layer of density water;

[0013] (3) Wait for the water surface to stabilize;

[0014] (4) According to the correspondence between the wave height and frequency of the wave maker, the frequency of the wave maker is adjusted to generate surface waves with a specific wave height and wavelength;

[0015] (5) Observe the positions of the upper and lower density water stratifications;

[0016] (6) After the second-mode internal wave is generated, stop the wave maker.

[0017] The method for generating laboratory surface waves and multi-modal internal waves by coupling, wherein: the upper layer of density water in step (1) can be ordinary fresh water with a specific density of 1, and the lower layer of density water is salt water with a specific density of 1.05.

[0018] By adopting the above technical solution, the present invention has the following beneficial effects:

[0019] The laboratory surface wave and multi-modal internal wave coupling generation device of the present invention has a simple and reasonable structural design and is easy to operate. By mixing salt water of different densities in a glass water tank and changing the layer depth ratio of salt water and pure water, and combining an automatic lifting platform to efficiently and quantitatively adjust the position of the wave-making block, and combining a frequency-adjustable wave-making machine, the coupled generation of surface waves and multi-modal internal waves of different wave heights and wavelengths can be achieved, thereby improving the wave-making accuracy and reducing the labor cost, and is suitable for promotion and application. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings in the following description are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0021] Figure 1 It is a schematic diagram of the structure of the laboratory surface wave and multi-mode internal wave coupling generation device of the present invention;

[0022] Figure 2 It is a structural schematic diagram of the automatic lifting platform of the laboratory surface wave and multi-mode internal wave coupling generation device of the present invention. DETAILED DESCRIPTION

[0023] The technical solution of the present invention will be described clearly and completely below 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 creative work are within the scope of protection of the present invention.

[0024] The present invention is further explained below in conjunction with specific implementation modes.

[0025] like Figure 1 As shown, the laboratory surface wave and multi-mode internal wave coupling generation device provided in this embodiment includes a glass water tank 1, an automatic lifting platform 2, a wave maker 3, a wave maker block 4 and a wave-breaking plate 5.

[0026] The glass water tank 1 comprises a water tank body 11 and pillars 12; wherein the water tank body 11 has an accommodating space inside and is filled with water of different densities; the water tank body 11 is placed on the ground by matching a plurality of pillars 12 vertically fixed on the outer walls at both ends thereof.

[0027] The automatic lifting platform 2 is a scissor-type electric lifting platform, which is matched and arranged at one end of the water tank body 11 of the glass water tank 1 and includes a base 21, a guide rail 22, a stepper motor 23, a transmission mechanism 24, a lifting frame 25 and a table 26. The base 21 is matched and fixed to the upper part of one end of the water tank body 11 of the glass water tank 1; the guide rail 22 is matched and fixed horizontally to the upper part of the base 21; the stepper motor 23 is matched and arranged on the outer side of one end of the base 21, and its power output end extends horizontally to the upper part of the base 21. The transmission mechanism 24 is composed of a lead screw 241 and a lead screw seat 242; one end of the lead screw 241 is matched and fixedly connected to the power output end of the stepper motor 23, and the other end is matched and hinged with a bearing seat 243; the bearing seat 243 is matched and fixed on the base 21 at the end of the travel of the guide rail 22; the lead screw seat 242 is slidably installed on the guide rail 22 through a slider and is connected to the lead screw 241 through a threaded fit, and the lead screw seat 242 is linearly displaced along the guide rail 22 under the drive of the lead screw 241. The lifting frame 25 includes a pair of support arms 251; the middle sections of the pair of support arms 251 are matched and hinged to each other through a hinge shaft 252; the lower end of one of the support arms 251 is matched and hinged with the lead screw seat 242 of the transmission mechanism 24, and the lower end of the other support arm 251 is matched and hinged with a support 253; the support 253 is matched and fixed to the upper part of the other end of the base 21 away from the stepper motor 23. The tabletop 26 is horizontally mounted on the upper ends of the pair of arms 251 , with the bottom of one end being hinged to the upper end of one of the arms 251 , and the bottom of the other end being hinged to the upper end of the other arm 251 .

[0028] The wave maker 3 is matched and arranged on the table top 26 of the automatic lifting platform 2, and includes a servo motor 31 and a crank connecting rod 32; the servo motor 31 is placed on the table top 26 of the automatic lifting platform 2, and its power output end is matched and connected to one end of the crank connecting rod 32; the other end of the crank connecting rod 32 extends vertically downward into the water tank body 11 of the glass water tank 1.

[0029] The wave-making block 4 is matched and installed on the other end of the crank connecting rod 32 of the wave-making machine 3; wherein, the rotation of the servo motor 31 is converted into a linear reciprocating motion of the wave-making block 4 through the crank connecting rod 32, and the wave-making frequency can be continuously changed by changing the rotation speed of the servo motor 31, and the oscillation stroke of the wave-making block 4 can be achieved by changing the length of the connecting rod in the crank connecting rod 32.

[0030] The wave-breaking plate 5 is arranged in an inclined manner inside the other end of the water tank body 11 of the glass water tank 1, and forms an angle of 15-20 degrees with the bottom of the water tank body 11, which can better eliminate surface waves or internal waves.

[0031] The method for generating laboratory surface waves and multi-mode internal waves by coupling according to the present invention comprises the following steps:

[0032] (1) Two layers of density stratified water are configured according to the size of the glass water tank 1; the upper layer of density water can be ordinary fresh water with a specific density of 1, and the lower layer of density water is salt water with a specific density of 1.05; the layer depth ratio is strictly controlled, and the layer depth ratio is: 1:4 (upper layer depth: lower layer depth). Under this layer depth ratio, two-mode internal waves can appear; wherein, the layer depth ratio here is not fixed and can be adjusted according to needs;

[0033] (2) According to the size of the glass water tank 1 and the oscillation stroke of the wave maker 3, the extreme position of the wave block 4 is adjusted (adjusted by the automatic lifting platform 2), so that the lowest position (lower edge) of the wave block 4 is located above the two layers of density water stratification, and the highest position (center) of the wave block 4 is located below the surface of the upper layer of density water;

[0034] (3) After adjusting the above steps (1) and (2), let it stand until the water surface stabilizes;

[0035] (4) According to the correspondence between the wave height and the frequency of the wave maker 3, the frequency of the wave maker 3 is adjusted to generate surface waves with a specific wave height and wavelength;

[0036] (5) Observe the location of the two-layer density water stratification;

[0037] (6) After the second-mode internal wave is generated, the wave maker 3 is stopped.

[0038] The present invention can realize the coupled generation of surface waves and multi-modal internal waves with different wave heights and wavelengths, improves the wave-making accuracy and reduces the labor cost, and is suitable for promotion and application.

[0039] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A laboratory surface wave and multi-mode internal wave coupling generation device, characterized in that: The generating device comprises a glass water tank, an automatic lifting platform, a wave maker, a wave maker block and a wave-breaking plate; The interior of the glass water tank is filled with water of different densities; The automatic lifting platform is matched and arranged on the upper part of one end of the glass water tank; The wave maker is matched and arranged on the automatic lifting platform and is lifted and lowered under the drive of the automatic lifting platform; the wave maker block is matched and installed on the power output end of the wave maker; the wave maker block is located inside the glass water tank; The wave-breaking plate is matched and arranged inside the other end of the glass water tank and forms an angle of 15-20° with the bottom of the glass water tank; The glass water tank comprises a water tank body and a support; the water tank body has a containing space inside and is filled with water of different densities; the water tank body is placed on the ground through a plurality of supports vertically fixed on the outer walls at both ends thereof; The automatic lifting platform adopts a scissor-type electric lifting platform, which is matched and arranged at one end of the water tank body and includes a base, a guide rail, a stepper motor, a transmission mechanism, a lifting frame and a table top; the base is matched and fixed to the upper part of one end of the water tank body; the guide rail is matched and fixedly arranged horizontally on the upper part of the base; the stepper motor is matched and arranged on the outer side of one end of the base, and its power output end extends horizontally to the top of the base; the transmission mechanism is composed of a screw and a screw seat; one end of the screw is matched and fixedly connected to the power output end of the stepper motor, and the other end is matched and hinged with a bearing seat; the bearing seat is matched and fixed to the base on one side of the end of the guide rail travel. The guide rail is provided with a plurality of support arms, and the support arms are connected to the guide rail by a threaded connection. The guide rail is linearly displaced along the guide rail by the drive of the guide rail. The lifting frame includes a pair of support arms. The middle sections of the pair of support arms are matched and hinged to each other through a hinge shaft. The lower end of one of the support arms is matched and hinged to the guide rail, and the lower end of the other support arm is matched and hinged to a support. The support is matched and fixed to the upper part of the other end of the base. The table is matched and horizontally installed on the upper ends of the pair of support arms, and the bottom of one end is matched and hinged to the upper end of one of the support arms, and the bottom of the other end is matched and hinged to the upper end of the other support arm. The wave maker is matched and arranged on the table, and comprises a servo motor and a crank connecting rod; the servo motor is arranged on the table, and its power output end is matched and connected to one end of the crank connecting rod; the other end of the crank connecting rod vertically extends downward into the interior of the water tank body; The wave-making block is matched and installed on the other end of the crank-connecting rod; the rotation of the servo motor is converted into the linear reciprocating motion of the wave-making block through the crank-connecting rod; the servo motor can continuously change the wave-making frequency by changing its rotation speed, and the oscillation stroke of the wave-making block can be achieved by changing the length of the connecting rod in the crank-connecting rod.

2. A method for generating laboratory surface waves and multi-mode internal waves coupled, based on the laboratory surface waves and multi-mode internal waves coupled generating device described in claim 1, characterized in that , specifically including the following steps: (1) Configure the upper and lower layers of density-stratified water according to the size of the glass water tank, and strictly control the layer depth ratio; (2) According to the size of the glass water tank and the oscillation stroke of the wave maker, the extreme position of the wave maker is adjusted so that the lowest position of the wave maker is located above the two layers of density water stratification and the highest position of the wave maker is located below the surface of the upper layer of density water; (3) Wait for the water surface to stabilize; (4) According to the correspondence between the wave height and frequency of the wave maker, the frequency of the wave maker is adjusted to generate surface waves with a specific wave height and wavelength; (5) Observe the positions of the upper and lower density water stratifications; (6) After the second-mode internal wave is generated, stop the wave maker.

3. The method for generating laboratory surface waves and multi-mode internal waves coupled according to claim 2, characterized in that: The upper layer of density water in step (1) may be ordinary fresh water with a specific density of 1, and the lower layer of density water may be salt water with a specific density of 1.05.

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