A water tank testing device and testing method for the influence of internal waves on the navigation of self-propelled model aircraft

Abstract

The invention relates to a pool testing device and a testing method for the influence of internal waves on the navigation of a self-propelled model. The device comprises a magnetic fluid layer, a fresh water layer, a self-propelled model, an oleophobic layer, a strong magnetic block, a load-dumping mechanism, a steering mechanism and the like. Oil-based magnetic fluid and water are used as layered liquids, and a magnetic pole attraction method is adopted to create single-peak or multi-peak internal waves of motion or stability and arbitrary shapes, thereby broadening the wave-making range. The load-dumping and steering mechanisms are made of magnetic materials. The device automatically dumps load or steers after encountering magnetic fluid, and automatically restores the rudder angle after entering the water again. No energy or power is required, and the execution timing is properly grasped, thereby solving the problem that it is difficult to control the execution timing of the load-dumping or steering. After passing through the wave surface, the self-propelled model automatically absorbs part of the magnetic fluid to enter the water for navigation, and automatically increases the micro-positive buoyancy, thereby eliminating the interference of the residual buoyancy retained in the traditional test on the test.

Description

Technical Field

[0001] The invention relates to the technical field of stratified flow pool model test devices, in particular to a pool test device and a test method for the influence of internal waves on the navigation of a self-propelled model. Background Art

[0002] Ocean internal waves are caused by seawater density stratification, which is then induced by excitation mechanisms such as topography and ocean currents. They have an important impact on the safe navigation of underwater submersibles. Therefore, targeted research is needed. Ocean internal waves have various waveforms, among which the highly destructive internal solitary waves and the frequently occurring multi-peak nonlinear internal waves are more valuable for research. In the field of water tank tests, the current main method of achieving density stratification is to add salt to fresh water, and then to achieve wave generation of internal solitary waves by dam breaking, shaking plate or other excitation methods, and finally to test and measure the motion response of a self-propelled model through the internal waves.

[0003] The current experimental scheme has the following shortcomings:

[0004] 1) It can only create single-peak internal solitary waves in motion, with unstable waveforms and gradual dissipation, and cannot create multi-peak internal wave trains that are more common in the actual ocean;

[0005] 2) The internal waves are in a propagation state, and the test timing of the self-propelled aircraft passing through the wave crest is demanding and the operation is difficult;

[0006] 3) In order to prevent the self-propelled model from hitting the bottom of the pool after passing through the internal waves, the hull usually needs to have a slight positive buoyancy, which will interfere with the test;

[0007] 4) In order to simulate the effect of dumping load or steering to resist falling depth, a complex dumping load and steering system is required. In addition, the anti-internal wave measures usually need to be executed after entering the wave surface, the timing of dumping load is required, and the human control factor has a great influence on the test.

[0008] 5) The size of the water tank is limited, and the problems of collision avoidance and braking are prominent. Usually, the test speed can only be reduced, which limits the scope of the test.

[0009] There is an urgent need for a new tank testing device and method for solving the above problems of the influence of internal waves on the navigation of self-propelled models. Summary of the invention

[0010] In view of the shortcomings in the above-mentioned existing production technology, the applicant provides a pool testing device and method for the influence of internal waves on the navigation of self-propelled models, so that oil-based magnetic fluid and water are used as layered liquids, and magnetic pole attraction is adopted to create single-peak or multi-peak internal waves of movement or stability and arbitrary shapes, thereby broadening the range of wave making. The load-dumping and steering mechanisms are made of magnetic materials, and the load-dumping or steering mechanisms are automatically dumped or steered after encountering magnetic fluid, and the steering angle is automatically restored after entering the water again. No energy power is required, and the execution timing is appropriate, which solves the problem that the timing of load-dumping or steering execution is difficult to control. After passing through the wave surface, the self-propelled model automatically absorbs part of the magnetic fluid to enter the water for navigation, automatically increases the micro-positive buoyancy, and eliminates the interference of the residual buoyancy on the test in the traditional test. Strong magnetic blocks are arranged around the pool to form a magnetic fluid domain. Once the self-propelled model enters, it will automatically dump its load and float up to avoid hitting the wall.

[0011] The technical solution adopted by the present invention is as follows:

[0012] A water pool testing device for the influence of internal waves on the navigation of a self-propelled model comprises a water pool, the water pool is surrounded by water pool walls, a magnetic fluid and fresh water are contained in the water pool, the magnetic fluid is lighter than water, and is automatically stratified in the water pool to form a fresh water layer and a magnetic fluid layer, and the magnetic fluid layer floats above the fresh water layer; a magnetic attraction system is installed at the bottom of the water pool, the magnetic attraction system comprises a slide rail fixed to the bottom of the water pool, a trailer is installed on the slide rail, a strong magnetic block is installed on the trailer, side wall magnetic blocks are respectively installed on both sides of the water pool wall, and end magnetic blocks are respectively installed at both ends of the water pool wall; a self-propelled model is also included, the self-propelled model The mold is equipped with a jettisoning mechanism, a steering mechanism and an attitude sensor. The installation structure of the jettisoning mechanism is as follows: it includes a buoyancy material fixed to the bottom of the self-propulsion model, a mounting panel is arranged at the bottom of the buoyancy material, jettisoning blocks are arranged at intervals at the bottom of the mounting panel, and a plurality of small springs are arranged between the mounting panel and the jettisoning blocks; the structure of the steering mechanism is as follows: it includes a rudder blade, a rudder shaft and a rudder heel, a first strong magnetic sheet is installed on the end face of the rudder heel, a second strong magnetic sheet is installed on the root face of the rudder blade, a torsion spring is sleeved on the rudder shaft, and the rudder shaft rotates freely on the rudder heel; it also includes an optical camera.

[0013] Its further technical solution is:

[0014] The pool is a rectangular structure with an open top.

[0015] The surrounding and bottom walls of the pool are made of transparent glass.

[0016] The outside of the self-propelled aircraft model is provided with an oleophobic layer.

[0017] The buoyancy material is connected to the self-propelled model and the mounting panel by gluing.

[0018] The mounting panel is a strong magnet.

[0019] The dump load block is made of iron material.

[0020] The first strong magnetic sheet and the second strong magnetic sheet are arranged opposite to each other.

[0021] The first strong magnetic sheet and the second strong magnetic sheet are respectively adhered to the rudder blade and the rudder heel by waterproof adhesive.

[0022] A water tank testing device and testing method for the influence of internal waves on the navigation of a self-propelled model aircraft, comprising the following steps:

[0023] S1: modulated magnetic fluid layer;

[0024] A magnetic fluid that meets the viscosity and density requirements is created by mixing multiple magnetic fluids. Usually, a magnetic fluid with a viscosity close to that of water and a density less than that of water is selected, and the magnetic fluid is injected into a pool with water at the bottom;

[0025] S2: modulated internal wave;

[0026] By increasing or decreasing the arrangement of strong magnetic blocks on the trailer under the pool, the magnetic attraction is adjusted to create a single-peak or multi-peak series of internal waves. When the trailer is stationary, a stationary internal wave is created, and when the trailer moves at a certain speed, a traveling internal wave is created;

[0027] S3: creating an oleophobic layer;

[0028] Put the self-propelled model into the oleophobic layer solution, so that the surface and the inner surface of the ship have the oleophobic layer to prevent the self-propelled model from sticking to the magnetic fluid;

[0029] S4: Automatic load dumping setting;

[0030] When conducting a test without jettisoning, remove the jettisoning block and the small spring, replace the buoyancy block to achieve zero buoyancy of the jettisoning mechanism underwater, and realize that the self-propelled model does not need to retain residual buoyancy, and automatically increases positive buoyancy after crossing the internal waves. When conducting a test with jettisoning, install the jettisoning block, and replace the buoyancy block to achieve zero buoyancy of the jettisoning mechanism underwater. The self-propelled model automatically triggers jettisoning after entering the magnetic fluid area above the wave surface;

[0031] S5: automatic steering setting;

[0032] Remove the first strong magnetic sheet and the second strong magnetic sheet, remove the waterproof glue between the torsion spring and the rudder heel, rotate the rudder connected to the rudder shaft and the torsion spring to the set rudder angle, ensure that the spring has no torsion, and then glue the end of the torsion spring to the rudder heel with waterproof glue; then install the first strong magnetic sheet and the second strong magnetic sheet on the rudder blade and the rudder heel respectively, the two magnetic sheets will generate magnetic attraction, which will force the rudder to rotate to the zero rudder angle state. At this time, the torsion spring has torsion; after entering the magnetic fluid area above the wave surface, the magnetic fluid is adsorbed on the two magnetic sheets, which plays a role in shielding the magnetic force. Under the action of the torsion of the torsion spring, the rudder automatically hits the set rudder angle, realizing the raising rudder angle and recovering the depth control. When the self-propelled model enters the water again, the water flow will wash away the magnetic fluid, and the two magnetic sheets will restore the mutual magnetic force, causing the rudder angle to return to zero;

[0033] S6: Anti-collision wall setting;

[0034] Anti-collision magnetic blocks are fixedly placed outside the four walls of the pool to absorb the magnetic fluid to form a magnetic fluid layer of a certain thickness. When the self-propelled aircraft model yaws or fails to brake in time and enters the magnetic fluid area, it will automatically jettison and float up to prevent collision with the wall.

[0035] S7: Data collection;

[0036] The onboard attitude sensor is used to measure the real-time attitude of the hull, and the optical camera records the internal wave waveform and the movement process of the hull.

[0037] The beneficial effects of the present invention are as follows:

[0038] The invention has a compact and reasonable structure and is easy to operate. Through the cooperation of the magnetic fluid layer, the fresh water layer, the magnetic attraction system, the self-propelled model, the load-dumping mechanism and the steering mechanism, the water tank test of the influence of internal waves on the navigation of the self-propelled model can be conveniently completed. Oil-based magnetic fluid and water are used as layered liquids, and magnetic pole attraction is adopted to create single-peak or multi-peak internal waves of movement or stability and arbitrary shapes, thereby broadening the wave-making range. The load-dumping and steering mechanisms are made of magnetic materials. After encountering the magnetic fluid, the load is automatically dumped or steered, and the rudder angle is automatically restored after entering the water again. No energy power is required, and the execution timing is properly grasped, thereby solving the problem that the timing of load-dumping or steering execution is difficult to control.

[0039] At the same time, the present invention has the following advantages:

[0040] (1) It can create internal waves with arbitrary shapes and stable states, especially nonlinear internal waves with multiple peaks that are difficult to achieve in conventional experiments, thus broadening the wave-making range and simplifying the wave-making equipment.

[0041] (2) The load-dumping and steering mechanisms are greatly simplified, and no power input is required, which reduces the burden on the self-propulsion model system and reduces the test cost.

[0042] (3) After entering the wave surface, the load jettisoning or steering is automatically triggered, and the timing is appropriate, without the need for manual operation, thus solving the problem of difficult control of the timing of load jettisoning.

[0043] (4) In the no-load test, the self-propelled model does not need to retain positive buoyancy, which avoids the interference of positive buoyancy. After passing through the internal waves, the positive buoyancy is automatically increased to prevent bottoming, allowing the test speed to be increased. After the test is completed, the self-propelled model will automatically float near the stratification interface for easy salvage.

[0044] (5) It is convenient to set up a safe area around the pool to avoid hitting the wall. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 It is a structural schematic diagram of the present invention.

[0046] Figure 2 It is a cross-sectional view of the water pool of the present invention.

[0047] Figure 3 It is a structural schematic diagram of the self-propelled model of the present invention.

[0048] Figure 4 for Figure 3 A partial enlarged view of part A in the middle.

[0049] Figure 5 It is a structural schematic diagram of the steering mechanism of the present invention.

[0050] Among them: 1. Pool wall; 2. Magnetic fluid layer; 3. Fresh water layer; 4. Magnetic suction system; 5. Self-propelled model; 6. Oleophobic layer; 7. Load-dumping mechanism; 8. Steering mechanism; 9. Attitude sensor; 10. Optical camera;

[0051] 401, trailer; 402, slide rail; 403, side wall magnetic block; 404, end magnetic block;

[0052] 701, buoyancy material; 702, mounting panel; 703, small spring; 704, dumping block;

[0053] 801, rudder blade; 802, rudder shaft; 803, rudder heel; 804, torsion spring; 805, first strong magnetic sheet; 806, second strong magnetic sheet. DETAILED DESCRIPTION

[0054] The specific implementation of the present invention will be described below in conjunction with the accompanying drawings.

[0055] like Figure 1-Figure 5As shown, the water pool test device for the influence of internal waves on the navigation of a self-propelled model in this embodiment includes a water pool, which is surrounded by a water pool wall 1. The water pool is filled with magnetic fluid and fresh water. The magnetic fluid is lighter than water, so it is automatically stratified in the water pool to form a fresh water layer 3 and a magnetic fluid layer 2, and the magnetic fluid layer 2 floats above the fresh water layer 3; a magnetic attraction system 4 is installed at the bottom of the water pool, and the magnetic attraction system 4 includes a slide rail 402 fixed to the bottom of the water pool, a trailer 401 is installed on the slide rail 402, and a strong magnetic block is installed on the trailer 401, and side wall magnetic blocks 403 are respectively installed on both sides of the water pool wall 1, and end magnetic blocks 404 are respectively installed at both ends of the water pool wall 1; it also includes a self-propelled model 5, and the self-propelled model 5 is equipped with a dumping mechanism 7 and a steering mechanism 8 and attitude sensor 9, the installation structure of the jettisoning mechanism 7 is as follows: it includes a buoyancy material 701 fixed to the bottom of the self-propelled model 5, a mounting panel 702 is arranged at the bottom of the buoyancy material 701, a jettisoning block 704 is arranged at intervals at the bottom of the mounting panel 702, and a plurality of small springs 703 are arranged between the mounting panel 702 and the jettisoning block 704; the structure of the steering mechanism 8 is as follows: it includes a rudder blade 801, a rudder shaft 802 and a rudder heel 803, a first strong magnetic sheet 805 is installed on the end surface of the rudder heel 803, a second strong magnetic sheet 806 is installed on the blade root surface of the rudder blade 801, a torsion spring 804 is sleeved on the rudder shaft 802, and the rudder shaft 802 rotates freely on the rudder heel 803; and it also includes an optical camera 10.

[0056] The pool is a rectangular structure with an open top.

[0057] The surrounding and bottom walls of the pool are made of transparent glass.

[0058] An oleophobic layer 6 is arranged on the outside of the self-propelled aircraft model 5 .

[0059] The buoyancy material 701 is connected to the self-propelled model 5 and the installation panel 702 by gluing.

[0060] The mounting panel 702 is a strong magnet.

[0061] The dump block 704 is made of iron material.

[0062] The first strong magnetic sheet 805 and the second strong magnetic sheet 806 are arranged opposite to each other.

[0063] The first strong magnetic sheet 805 and the second strong magnetic sheet 806 are respectively attached to the rudder blade 801 and the rudder heel 803 by waterproof adhesive.

[0064] The water pool testing device and testing method of the present embodiment for the influence of internal waves on the navigation of a self-propelled model aircraft include the following steps:

[0065] S1: modulated magnetic fluid layer 2;

[0066] A magnetic fluid that meets the viscosity and density requirements is created by mixing multiple magnetic fluids. Usually, a magnetic fluid with a viscosity close to that of water and a density less than that of water is selected, and the magnetic fluid is injected into a pool with water at the bottom;

[0067] S2: modulated internal wave;

[0068] By increasing or decreasing the arrangement of the strong magnetic blocks on the trailer 401 under the pool, the magnetic attraction is adjusted to create a single-peak or multi-peak series of internal waves. When the trailer 401 is stationary, a stationary internal wave is created. When the trailer 401 moves at a certain speed, a traveling internal wave is created.

[0069] S3: creating an oleophobic layer 6;

[0070] The self-propelled aircraft model 5 is placed in the oleophobic layer solution, so that the surface and the inner surface of the ship have the oleophobic layer 6 to prevent the self-propelled aircraft model 5 from sticking to the magnetic fluid;

[0071] S4: Automatic load dumping setting;

[0072] When the non-load dumping test is conducted, the dumping block 704 and the small spring 703 are removed, and the buoyancy block is replaced to achieve zero buoyancy of the dumping mechanism 7 underwater, so that the self-propelled model 5 does not need to have any residual buoyancy, and automatically increases positive buoyancy after crossing the internal waves. When the load dumping test is conducted, the dumping block 704 is installed, and the underwater zero buoyancy of the dumping mechanism 7 is achieved by replacing the buoyancy block, and the self-propelled model 5 automatically triggers the dumping after entering the magnetic fluid area above the wave surface;

[0073] S5: automatic steering setting;

[0074] Remove the first strong magnetic sheet 805 and the second strong magnetic sheet 806, remove the waterproof glue between the torsion spring 804 and the rudder heel 803, rotate the rudder to the set rudder angle with the rudder shaft 802 and the torsion spring 804, ensure that the spring has no torsion, and then glue the end of the torsion spring 804 to the rudder heel 803 with waterproof glue; then install the first strong magnetic sheet 805 and the second strong magnetic sheet 806 on the rudder blade 801 and the rudder heel 803 respectively, the two magnetic sheets generate magnetic attraction, which will force the rudder to rotate to the zero rudder angle state. At this time, the torsion spring 804 has torsion; after entering the magnetic fluid area above the wave surface, the magnetic fluid is adsorbed on the two magnetic sheets, which plays a role in shielding the magnetic force. Under the action of the torsion of the torsion spring 804, the rudder automatically hits the set rudder angle, realizing the lifting rudder angle to recover the depth control, and when the self-propelled model 5 enters the water again, the water flow will wash away the magnetic fluid, and the two magnetic sheets will restore the mutual magnetic force, prompting the rudder angle to return to zero;

[0075] S6: Anti-collision wall setting;

[0076] Anti-collision magnetic blocks are fixedly placed outside the four walls of the pool to absorb magnetic fluid to form a magnetic fluid layer 2 of a certain thickness. When the self-propelled aircraft model 5 yaws or fails to brake in time and enters the magnetic fluid area, it will automatically jettison and float to prevent collision with the wall;

[0077] S7: Data collection;

[0078] The boat-borne attitude sensor 9 is used to measure the real-time attitude of the boat body, and the optical camera 10 records the internal wave waveform and the movement process of the boat body.

[0079] The specific structure and function of the water tank testing device for the influence of internal waves on the navigation of a self-propelled model aircraft described in the present invention are as follows:

[0080] It mainly includes a pool wall 1, a magnetic fluid layer 2, a fresh water layer 3, a magnetic suction system 4, a self-propelled model 5, an oleophobic layer 6, a jettisoning mechanism 7, a steering mechanism 8, a posture sensor 9 and an optical camera 10.

[0081] The pool is in the shape of a cuboid, with the surrounding and bottom walls made of transparent glass.

[0082] The pool is filled with magnetic fluid and fresh water, which are automatically separated into layers. Usually, a magnetic fluid that is lighter than water is selected, and the magnetic fluid floats on top.

[0083] The slide rail 402 is fixed to the bottom of the pool, and the trailer 401 is fixed to the slide rail 402 and can move at a set speed on the slide rail 402. The trailer 401 is equipped with strong magnetic blocks, and the magnetic attraction of the magnetic fluid can be modulated by changing the number or arrangement of the strong magnetic blocks.

[0084] The jettisoning mechanism 7 is composed of a buoyancy material 701 , a mounting panel 702 , a small spring 703 and a jettisoning block 704 .

[0085] The buoyancy material 701 is bonded to the mounting panel 702 below with glue, and the upper part is pasted to the self-propelled model 5 to fix the jettisoning mechanism 7. The underwater negative buoyancy of the jettisoning mechanism 7 is adjusted by changing the buoyancy material 701. The mounting panel 702 is a strong magnet, the jettisoning block 704 is an iron material, and a small spring 703 is pasted on the jettisoning block 704. The mounting panel 702 attracts the jettisoning block 704 by magnetic force and compresses the small spring 703 to fix the jettisoning block 704. Due to the existence of the small spring 703, there is still a gap between the mounting panel 702 and the jettisoning block 704.

[0086] The steering mechanism 8 is composed of a rudder blade 801 , a rudder shaft 802 , a rudder heel 803 , a torsion spring 804 , a first strong magnetic sheet 805 and a second strong magnetic sheet 806 .

[0087] The rudder shaft 802 is fixed on the rudder surface, passes through the middle of the torsion spring 804, and is installed on the rudder heel 803. The rudder shaft 802 can rotate freely on the rudder heel 803. The first strong magnetic sheet 805 and the second strong magnetic sheet 806 are respectively attached to the root surface of the rudder blade 801 and the end surface of the rudder heel 803 with waterproof glue.

[0088] The attitude sensor 9 is installed on the self-propelled model 5 for real-time measurement of the boat's attitude.

[0089] The optical camera 10 is fixed on the glass on one side of the pool wall 1 to record the internal wave waveform and the movement of the self-propelled aircraft model 5 at a fixed point.

[0090] In actual working process:

[0091] (I) Modulating magnetic fluid layer 2:

[0092] According to the test requirements, the density and viscosity of the magnetic fluid are modulated. The required magnetic fluid can be obtained by mixing a plurality of magnetic fluids of different densities and viscosities. Generally, a magnetic fluid with the same viscosity as water and a density lighter than water is modulated to simulate the concave internal wave, and the present invention is described in this case.

[0093] (ii) Modulation of internal wave waveform:

[0094] The trailer 401 is suspended at the bottom of the pool and can move forward and backward. The trailer 401 is equipped with strong magnetic blocks, and the magnetic attraction can be adjusted by changing the number or arrangement of the strong magnetic blocks. The magnetic attraction passes through the lower layer of water, attracting the upper layer of magnetic fluid to concave, forming an internal wave waveform. Under the action of the magnetic attraction, in addition to single-peak internal solitary waves, multi-peak internal wave trains that are difficult to obtain in conventional tests can also be created, greatly broadening the test range.

[0095] When the trailer 401 is stationary, a stationary internal wave can be created, and when the trailer 401 is moving, a traveling internal wave can be created. The internal wave waveform is stable and the position is controllable, which avoids the dissipation problem of the moving internal wave in the conventional test, and also reduces the difficulty of controlling the timing when the self-propelled model 5 encounters the traveling internal wave.

[0096] (III) Creating an oleophobic layer 6:

[0097] The self-propelled model 5 is placed in the oleophobic liquid and allowed to stand for a period of time. After being taken out again, an oleophobic coating can be formed on both the inner and outer surfaces of the light outer shell of the self-propelled model 5, thereby eliminating the problem of the self-propelled model 5 sticking to the magnetic fluid oil.

[0098] (IV) Automatic load dumping setting:

[0099] Before the test, the self-propelled model 5 is adjusted to a zero buoyancy state underwater. According to the test requirements, it is divided into a no-load test and a load-dump test:

[0100] When the self-propelled model 5 is tested for the motion response of the internal wave without jettisoning, the jettisoning block 704 and the small spring 703 are removed, and the buoyancy block is replaced to achieve zero buoyancy of the jettisoning mechanism 7 underwater. During the test, the self-propelled model 5 with the jettisoning mechanism 7 has no residual buoyancy in the water in front of the internal wave. When in the magnetic fluid on the wave surface, the influence of the jettisoning mechanism 7 can be ignored. Thus, the interference of the residual positive buoyancy in the traditional test is avoided. After passing through the wave surface and entering the water again, the installation panel 702 absorbs part of the magnetic fluid to accompany the hull to sail. The density of the magnetic fluid is less than that of water, which automatically adds positive buoyancy to the self-propelled model 5, reduces the depth drop after passing through the internal wave, and avoids the hull from touching the bottom, thereby increasing the test speed and widening the test range. After the test, the self-propelled model 5 will float at the junction of water and magnetic fluid under the action of positive buoyancy, which is convenient for salvage and avoids the bottom collision of the hull.

[0101] When the dumping test is carried out, a dumping block 704 with a weight of m is selected according to the needs, and the underwater zero buoyancy of the dumping mechanism 7 is achieved by replacing the buoyancy block. After the dumping mechanism 7 is attached to the self-propelled model 5 by waterproof glue, it has no effect on the residual underwater buoyancy of the self-propelled model 5. After entering the wave surface, the magnetic fluid will fill the gap between the dumping block 704 and the mounting panel 702, which plays a role in shielding the magnetic force, weakening the attraction between the two, causing the dumping block 704 to automatically fall with the spring. In this way, after encountering an internal wave and entering the wave surface, the self-propelled model 5 automatically dumps the load without human control, and the timing is appropriate.

[0102] (V) Automatic steering settings:

[0103] According to the test requirements, set the maximum rudder angle of the automatic steering. Remove the strong magnetic block and remove the waterproof glue between the spring and the rudder heel 803, then the rudder can rotate freely with the spring. After turning to the set rudder angle, make sure that the spring has no torsion, and then glue the end of the spring to the rudder heel 803 with waterproof glue. After installing the two magnetic blocks on the rudder root and rudder heel 803 respectively, the two magnetic blocks will generate magnetic attraction, which will force the rudder to rotate to the zero rudder angle state. At this time, the spring has torsion.

[0104] At the beginning of the test, the self-propelled aircraft model 5 is in the fresh water layer 3, and the elevator is always at zero rudder angle. Once entering the magnetic fluid, the strong magnetic block will automatically absorb the magnetic fluid, and the magnetic fluid will shield the magnetic force of the strong magnetic block. The magnetic attraction between the two strong magnetic blocks disappears, and under the action of the spring torsion, the elevator automatically reaches the set rudder angle.

[0105] When the self-propelled aircraft 5 passes through the wave surface and enters the water again, the steering device will automatically return to the zero rudder angle. During the navigation of the self-propelled aircraft model 5, the water flow will wash away the magnetic fluid adsorbed by the strong magnetic block, causing the magnetic fluid on the surface to fall off, the thickness of the magnetic fluid to decrease, and the magnetic attraction between the two strong magnetic blocks to increase, thereby reducing the rudder angle. After the rudder angle is reduced, the gap between the rudder blade 801 and the rudder heel 803 decreases, the flow rate increases, and the magnetic fluid is further reduced until the shielding effect of the magnetic fluid on the strong magnetic block disappears. The magnetic attraction between the two strong magnetic blocks is restored, prompting the elevator to rotate and achieving a zero rudder angle.

[0106] The steering device can automatically steer after entering the internal waves, and the timing is appropriate. After passing through the internal waves, it automatically returns to zero rudder angle without interfering with the state of the boat body. The steering device does not require a traditional steering gear, simplifies the test equipment, and meets the test requirements.

[0107] (VI) Anti-collision wall setting:

[0108] Anti-collision magnetic blocks are installed on the four walls of the pool to attract the magnetic fluid to flow into the bottom and fix it, forming a magnetic fluid layer 2 of a certain thickness. When the self-propelled aircraft 5 yaws or fails to slow down in time and enters the magnetic fluid area, it automatically triggers the load dumping to achieve buoyancy and avoid hitting the wall.

[0109] (VII) Data measurement:

[0110] The boat-borne attitude sensor 9 is used to measure the real-time attitude of the boat body. The optical camera 10 can record the internal wave waveform and the movement process of the boat body.

[0111] The entire test process can be completed through the above operation process. After passing through the wave surface, the self-propelled model 5 automatically absorbs part of the magnetic fluid and enters the water to sail, automatically increasing the micro-positive buoyancy, eliminating the interference of the residual buoyancy on the test in the traditional test. Strong magnetic blocks are arranged around the water pool to form a magnetic fluid domain. Once the self-propelled model 5 enters, it will automatically jettison the load and float up to avoid hitting the wall.

[0112] The above description is an explanation of the present invention, not a limitation of the present invention. The scope of the present invention is defined in the claims. Any form of modification may be made within the scope of protection of the present invention.

Claims

1. A water tank testing device for the influence of internal waves on the navigation of a self-propelled aircraft model, characterized in that: The invention comprises a pool, the pool is surrounded by a pool wall (1), a magnetic fluid and fresh water are contained in the pool, the magnetic fluid is lighter than water, and is automatically stratified in the pool to form a fresh water layer (3) and a magnetic fluid layer (2), the magnetic fluid layer (2) floats above the fresh water layer (3); a magnetic attraction system (4) is installed at the bottom of the pool, the magnetic attraction system (4) comprises a slide rail (402) fixed to the bottom of the pool, a trailer (401) is installed on the slide rail (402), a strong magnetic block is installed on the trailer (401), side wall magnetic blocks (403) are respectively installed on both sides of the pool wall (1), and end magnetic blocks (404) are respectively installed at both ends of the pool wall (1); and a self-propelled model (5) is also included, the self-propelled model (5) is installed with a dumping mechanism (7), a steering mechanism (8) and a posture sensor (9), the dumping mechanism (7) The installation structure comprises: a buoyancy material (701) fixed to the bottom of the self-propelled model (5); a mounting panel (702) is arranged at the bottom of the buoyancy material (701); a dumping block (704) is arranged at intervals at the bottom of the mounting panel (702); and a plurality of small springs (703) are arranged between the mounting panel (702) and the dumping block (704); the structure of the steering mechanism (8) comprises: a rudder blade (801), a rudder shaft (802) and a rudder heel (803); a first strong magnetic sheet (805) is installed on the end surface of the rudder heel (803); a second strong magnetic sheet (806) is installed on the blade root surface of the rudder blade (801); a torsion spring (804) is sleeved on the rudder shaft (802); and the rudder shaft (802) rotates freely on the rudder heel (803); and an optical camera (10) is also included.

2. A water tank testing device for the effect of internal waves on the navigation of a self-propelled aircraft model as claimed in claim 1, characterized in that: The pool is a rectangular structure with an open top.

3. A water tank testing device for the effect of internal waves on the navigation of a self-propelled aircraft model as claimed in claim 1, characterized in that: The surrounding and bottom walls of the pool are made of transparent glass.

4. A water tank testing device for the effect of internal waves on the navigation of a self-propelled aircraft model as claimed in claim 1, characterized in that: An oleophobic layer (6) is arranged on the outside of the self-propelled aircraft model (5).

5. A water tank testing device for the effect of internal waves on the navigation of a self-propelled aircraft model as claimed in claim 1, characterized in that: The buoyancy material (701) is connected to the self-propelled model (5) and the installation panel (702) by gluing.

6. A water tank testing device for the effect of internal waves on the navigation of a self-propelled aircraft model as claimed in claim 1, characterized in that: The mounting panel (702) is a strong magnet.

7. A water tank testing device for the effect of internal waves on the navigation of a self-propelled aircraft model as claimed in claim 1, characterized in that: The dump block (704) is made of iron material.

8. A water tank testing device for the effect of internal waves on the navigation of a self-propelled aircraft model as claimed in claim 1, characterized in that: The first strong magnetic sheet (805) and the second strong magnetic sheet (806) are arranged opposite to each other.

9. A water tank testing device for the effect of internal waves on the navigation of a self-propelled aircraft model as claimed in claim 1, characterized in that: The first strong magnetic sheet (805) and the second strong magnetic sheet (806) are respectively adhered to the rudder blade (801) and the rudder heel (803) by waterproof adhesive.

10. A method for testing the water tank test device for the influence of internal waves on the navigation of a self-propelled aircraft model as claimed in claim 4, characterized in that: The steps include: S1: Modulation magnetic fluid layer (2); By mixing multiple magnetic fluids to create a magnetic fluid that meets the viscosity and density requirements, a magnetic fluid with a viscosity close to that of water and a density less than that of water is selected, and the magnetic fluid is injected into a pool with water at the bottom; S2: modulated internal wave; By increasing or decreasing the arrangement of the strong magnetic blocks on the trailer (401) under the pool, the magnetic attraction is adjusted to create a single-peak or multi-peak series of internal waves. When the trailer (401) is stationary, a stationary internal wave is created. When the trailer (401) moves at a certain speed, a traveling internal wave is created. S3: creating an oleophobic layer (6); The self-propelled model (5) is placed in an oleophobic layer solution so that the surface and the inner surface of the ship have an oleophobic layer (6) to prevent the self-propelled model (5) from sticking to the magnetic fluid; S4: Automatic load dumping setting; When a test without a jettison load is conducted, the jettison load block (704) and the small spring (703) are removed, and the buoyancy block is replaced to achieve zero underwater buoyancy of the jettison load mechanism (7), so that the self-propelled model (5) does not need to have any residual buoyancy, and automatically increases positive buoyancy after crossing internal waves. When a test with a jettison load is conducted, the jettison load block (704) is installed, and the buoyancy block is replaced to achieve zero underwater buoyancy of the jettison load mechanism (7), and the self-propelled model (5) automatically triggers the jettison load after entering the magnetic fluid region above the wave surface; S5: automatic steering setting; Remove the first strong magnetic sheet (805) and the second strong magnetic sheet (806), remove the waterproof glue between the torsion spring (804) and the rudder heel (803), rotate the rudder connected to the rudder shaft (802) and the torsion spring (804) to the set rudder angle δ, ensure that the spring has no torsion, and then use waterproof glue to glue the end of the torsion spring (804) to the rudder heel (803); then install the first strong magnetic sheet (805) and the second strong magnetic sheet (806) on the rudder blade (801) and the rudder heel (803) respectively. After the self-propelled vehicle (5) is lifted up, the two magnetic sheets generate magnetic attraction, which will force the rudder to rotate to a zero rudder angle state. At this time, the torsion spring (804) has a torsion force. After entering the magnetic fluid area above the wave surface, the magnetic fluid is adsorbed on the two magnetic sheets, which plays a role in shielding the magnetic force. Under the action of the torsion force of the torsion spring (804), the rudder automatically moves to the set rudder angle, realizing the control of raising the rudder angle and recovering the depth. When the self-propelled vehicle (5) enters the water again, the water flow will wash away the magnetic fluid, and the mutual magnetic force between the two magnetic sheets will be restored, so that the rudder angle returns to zero. S6: Anti-collision wall setting; Anti-collision magnetic blocks are fixedly placed outside the four walls of the pool to absorb magnetic fluid to form a magnetic fluid layer (2) of a certain thickness. When the self-propelled aircraft model (5) deviates or fails to brake in time and enters the magnetic fluid area, it will automatically jettison and float up to prevent collision with the wall. S7: Data collection; The boat-borne attitude sensor (9) is used to measure the real-time attitude of the boat body, and the optical camera (10) records the internal wave waveform and the movement process of the boat body.

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