Test and measurement system suitable for researching influence of ship navigation on density current

Abstract

The invention discloses a test and measurement system suitable for researching the influence of ship navigation on density current, and relates to the technical field of ship navigation and hydrodynamic tests, and the system comprises a rectangular glass water tank, a movable water tank support frame, a ship control system with synchronous power traction and propeller rotating speed, a multifunctional measurement frame and a high-frequency high-precision PIVamp. And the measuring system is composed of a PLIF measuring system. According to the test and measurement system suitable for researching the influence of ship navigation on density current, the ship model control system can flexibly adjust the forward speed, match the corresponding propeller rotating speed, digitally display the rotating speed result, and automatically adjust the ship model draft, thereby ensuring the feasibility of mechanism test, and improving the test efficiency. The device of coupling the lead screw with the sliding rod ensures that the ship model is stable in operation process and free of jitter, the stability of the test and the accuracy of data are improved, and the measuring frame is simple in structure, convenient to assemble and disassemble and capable of being flexibly used for indoor water tank tests.

Description

Technical Field

[0001] The invention relates to the technical field of ship navigation and dynamics experiments, and in particular to a test and measurement system suitable for studying the influence of ship navigation on density flow. Background Art

[0002] When the gates of the estuary ship lock are opened, salt water will automatically flow upstream and form a stable stratified water body after a period of time. However, when the estuary ship lock is in operation, the disturbance of the hull and propeller will trigger the mixing movement of salt and fresh water, thereby carrying salt water into the reservoir area. Affected by the measurement technology, the mechanism of the impact of ship movement on salt water intrusion is still unclear, so the ecological and environmental benefits of the reservoir area still face certain threats.

[0003] In order to explore this mechanism, it is necessary to use PIV+PLIF technology to measure the flow field and salt water concentration field during the ship's movement. However, the PIV measurement system is complex, with numerous measuring devices and high requirements for the installation accuracy of the measuring equipment. In addition, the control of gate opening and closing and ship movement makes this measurement technology more complicated. How to synchronously control the ship's forward speed and propeller speed during the test, how to coordinate the gate opening and closing with the ship's movement track, and how to meet the high-precision requirements of PIV and PLIF measuring equipment for salt and fresh water during the ship's movement are major difficulties in the test. There is an urgent need for a digital display control system that can longitudinally control the ship's running speed and flexibly change the ship's draft vertically, as well as a measurement frame with a structure that can quickly adjust the measuring equipment. To solve this technical problem, the present invention provides a PIV+PLIF comprehensive measurement system under ship movement conditions. Summary of the invention

[0004] In order to overcome the shortcomings of the prior art, the present invention provides an intelligent control system and measurement method suitable for indoor water tank tests on the influence of ship motion on density flow disturbance. The system is highly integrated and can digitally adjust the ship motion system, and with the help of flexibly adjustable measuring equipment, integrated measurement is achieved, breaking through the technical barriers of high-precision measurement of density flow in lock chamber under the influence of ship disturbance.

[0005] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a test and measurement system suitable for studying the influence of ship navigation on heterogeneous flow, comprising a measurement system consisting of a rectangular glass water tank, a movable water tank support frame, a ship control system with power traction and propeller speed synchronization, a multifunctional measurement frame and a high-frequency and high-precision PIV&PLIF measurement system, wherein the glass water tank is made of quartz glass, four first brackets are installed near the bottom of the water tank support frame, a universal wheel is installed at the bottom of the first bracket, the top of the water tank support frame is fixedly installed by connecting the frame and the glass water tank, the ship model control system with power traction and propeller speed synchronization consists of a sliding platform, a hand-cranked The multifunctional measuring frame is composed of a digital display platform, a ship speed control motor, a propeller speed control motor, a propeller rotating connection component, a ship speed and speed digital display control box, a sliding device and a fully enclosed cable threading trough. The multifunctional measuring frame is 0.93m long, 0.60m wide and 1.50m high. It is composed of a main multifunctional measuring bracket, a main engine base plate, a laser base plate, a camera base plate, a camera adjustment tray, a laser corner device extension frame, a laser corner base plate, a laser corner support plate and a laser 45° corner mirror. The high-frequency and high-precision PIV&PLIF measurement system is composed of two high-speed cameras, a high-energy continuous laser, a time synchronizer and a PIV flow field / PLIF concentration field calculation program.

[0006] Preferably, the rectangular glass water tank is 4.5m long, 0.3m wide and 0.3m high. A gate partition for separating salt water and fresh water is configured 1.6m from the left side of the glass water tank. Both ends of the gate partition are embedded with a 10mm deep and 3.5mm wide waterstop.

[0007] Preferably, the sliding platform is composed of a steel main board with a length of 0.64m and a width of 0.4m. A third bracket is symmetrically fixedly connected to the top of the sliding platform, and a lifting support plate is fixedly connected between the outer surfaces of the two third brackets. Four sliding rod coupling sleeves are arranged at the bottom of the sliding platform. A screw coupling gear is installed at the top of the sliding platform near the right side, and a rectangular hole is opened in the center of the sliding platform.

[0008] Preferably, the hand-cranked digital display platform consists of a rotating handle, a displacement digital display device and a lifting bracket. The hand-cranked digital display platform is installed on the lifting support plate of the sliding platform and is located at the center position. The lifting bracket passes through the rectangular hole in the center of the sliding platform and a ship model is installed at the bottom. The ship speed control motor is installed on the right side of the sliding platform and is connected to the screw coupling gear. The forward speed of the sliding platform is controlled by the screw.

[0009] Preferably, a second bracket is installed at the bottom of the propeller speed control motor, the second bracket is installed on the top of the lifting bracket, and the propeller speed control motor is connected to the ship model through a supporting steel plate. The propeller speed control motor uses components such as a rotating shaft, a winding coupling and a right-angle coupling to be connected to the propeller at the tail of the ship model for controlling the propeller speed.

[0010] Preferably, the ship speed and rotation speed digital display control box is provided with two control switches, a digital propeller rotation speed controller, and a digital ship speed controller on the outside.

[0011] Preferably, the sliding device consists of a sliding rod device and a rack screw device, and the sliding rod device and the rack screw device are respectively installed on both sides of the top of the water tank support frame, the sliding rod device and the rack screw device are 0.4m long and 0.02m wide, and the sliding rod device and the screw device are nested with the sliding rod coupling sleeve and the screw coupling gear at the bottom of the sliding platform, and the fully enclosed cable threading trough is opened on the inner wall of the water tank support frame and the connecting wire of the ship model is embedded inside.

[0012] Preferably, the main multifunctional measuring bracket in the multifunctional measuring frame is made of four 1.5m long and eight 0.6m long aluminum alloy profiles, the main unit base plate, laser base plate and camera base plate are all composed of 0.93m long, 0.6m wide and 8mm thick aluminum alloy plates, and the main unit base plate, laser base plate and camera base plate are installed on the inner side of the multifunctional measuring bracket from bottom to top in sequence, the camera adjustment tray is composed of a threaded rotating bracket and two 0.297m long square panels, the vertical height can be adjusted to 0.2m, and the lower square panel is fixed on the top of the camera base plate, and the upper square panel and the PIV high-speed camera are connected with the PLIF high-speed camera.

[0013] Preferably, the laser corner device extension frame is installed on two vertical profiles in the middle part of the multifunctional measuring bracket, and the laser corner device extension frame can be adjusted up and down in the height direction, the laser corner base plate is fixed on the top of the laser corner device extension frame, and the laser corner support plate is installed on the top of the laser corner base plate for fixing the laser 45° corner mirror, and the laser 45° corner mirror consists of a triangular profile with a length of 0.2m and a side length of 50mm and a reflector with a length of 0.2m and a width of 0.15m.

[0014] Preferably, the high-speed cameras in the high-frequency and high-precision PIV&PLIF measurement system are respectively a PIV high-speed camera and a PLIF high-speed camera. The PIV high-speed camera is equipped with a 532nm narrow-band filter in front, which allows light with a wavelength of 512-550nm to pass through, and can effectively block the fluorescence released by the fluorescent dye from passing through the lens. The PLIF high-speed camera is equipped with a long-wave pass filter with a cut-off wavelength of 550nm in front to filter out the laser. The collected images are all in 8-bit BMP format. The camera and the computer communicate with each other in a local area network built on Ethernet to realize image data transmission. The high-energy continuous laser is a 2W semiconductor continuous laser, and the laser is a sheet of light with a wavelength of 532nm and a thickness of about 1mm. The time synchronizer is used to simultaneously collect images from the PIV high-speed camera and the PLIF high-speed camera, and the PIV and PLIF concentration fields are calculated using autonomous programming.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] 1. The ship model control system can flexibly adjust the forward speed, match the corresponding propeller speed, digitally display the speed results, and automatically adjust the draft depth of the ship model, ensuring the feasibility of the mechanism test.

[0017] 2. The device of screw rod coupling slide rod ensures the smooth and jitter-free operation of the ship model, which improves the stability of the test and the accuracy of the data.

[0018] 3. The measuring frame has a simple structure, is easy to assemble and disassemble, and can be flexibly used for indoor water tank tests.

[0019] 4. The laser corner extension frame provides a wide range of adjustment space for the laser corner 45° mirror, and uses vertical plane laser for convenient and quick formation. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 A top view of a test and measurement system for studying the influence of ship navigation on density flow according to the present invention;

[0021] Figure 2 A side view of a test and measurement system for studying the influence of ship navigation on density flow according to the present invention;

[0022] Figure 3 A cross-sectional view of a test and measurement system for studying the influence of ship navigation on density currents according to the present invention;

[0023] Figure 4 It is a partial structural schematic diagram of a test and measurement system suitable for studying the influence of ship navigation on density flow of the present invention;

[0024] Figure 5A top view of a sliding platform of a test and measurement system suitable for studying the influence of ship navigation on density flow according to the present invention;

[0025] Figure 6 This is a diagram of the accessories of a water tank support frame of a test and measurement system suitable for studying the influence of ship navigation on density flow in the present invention;

[0026] Figure 7 A schematic diagram of a ship model of a test and measurement system suitable for studying the influence of ship navigation on density currents according to the present invention;

[0027] Figure 8 The present invention is a schematic diagram of a gate diaphragm of a test and measurement system suitable for studying the influence of ship navigation on density flow.

[0028] In the figure:

[0029] 1. Sink support frame; 11. Glass sink; 12. First bracket; 13. Universal wheel; 14. Gate diaphragm; 15. Slide rod coupling sleeve; 16. Screw rod coupling gear; 2. Sliding platform; 21. Second bracket; 22. Ship speed control motor; 23. Lifting bracket; 24. Third bracket; 25. Lifting support plate; 26. Hand-cranked digital display platform; 27. Propeller speed control motor; 31. Rotating shaft; 32. Winding coupling; 33. Right-angle coupling; 4. Digital display control box for ship speed and rotation speed; 41. Control switch; 42. Digital display propeller speed controller; 43. Digital display ship speed controller; 5. Multi-function measuring bracket; 51. Main engine base plate; 52. Laser base plate; 53. Camera base plate; 54. Camera adjustment tray; 55. PIV high-speed camera; 56. PLIF high-speed camera; 6. Laser corner device extension frame; 61. Laser corner support plate; 62. Laser corner base plate; 63. Laser 45° corner mirror. DETAILED DESCRIPTION

[0030] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the implementation regulations described 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.

[0031] See also Figure 1-Figure 8 The present invention provides a technical solution: a test and measurement system suitable for studying the influence of ship navigation on density flow, such as Figure 1As shown, the test and measurement system of this embodiment is suitable for studying the influence of ship navigation on the density flow, including a measurement system consisting of a rectangular glass water tank 11, a movable water tank support frame 1, a ship control system with power traction and propeller speed synchronization, a multifunctional measurement frame and a high-frequency and high-precision PIV&PLIF measurement system. The glass water tank 11 is made of quartz glass, four first brackets 12 are installed near the bottom of the water tank support frame 1, and a universal wheel 13 is installed at the bottom of the first bracket 12. The top of the water tank support frame 1 is fixedly installed by connecting the frame and the glass water tank 11. The ship model control system with power traction and propeller speed synchronization consists of a sliding platform 2, a hand-cranked digital display platform 26, and a ship speed control electric The multifunctional measuring frame is composed of a machine 22, a propeller speed control motor 27, a propeller rotation connection component, a ship speed and speed digital display control box 4, a sliding device and a fully enclosed cable threading trough. The multifunctional measuring frame is 0.93m long, 0.60m wide and 1.50m high. It consists of a main multifunctional measuring bracket 5, a main engine base plate 51, a laser base plate 52, a camera base plate 53, a camera adjustment tray 54, a laser corner device extension frame 6, a laser corner base plate 62, a laser corner support plate 61 and a laser 45° corner mirror 63. The high-frequency and high-precision PIV&PLIF measurement system is composed of two high-speed cameras, a high-energy continuous laser, a time synchronizer and a PIV flow field / PLIF concentration field calculation program.

[0032] like Figure 1-Figure 3 , Figure 6 and Figure 8 As shown, the rectangular glass water tank 11 is 4.5m long, 0.3m wide and 0.3m high. A gate partition 14 for separating salt water and fresh water is arranged 1.6m away from the left side of the glass water tank 11. Both ends of the gate partition 14 are embedded with a 10mm deep and 3.5mm wide waterstop. The gate partition 14 is mainly used to separate the fresh water and salt water on both sides of the rectangular glass water tank 11. The waterstops at both ends of the gate partition 14 serve to improve the sealing effect.

[0033] like Figure 1-Figure 5 As shown, the sliding platform 2 is composed of a steel main board with a length of 0.64m and a width of 0.4m. The top of the sliding platform 2 is symmetrically fixedly connected with a third bracket 24, and a lifting support plate 25 is fixedly connected between the outer surfaces of the two third brackets 24. Four sliding rod coupling sleeves 15 are arranged at the bottom of the sliding platform 2. A screw coupling gear 16 is installed at the top of the sliding platform 2 near the right side. A rectangular hole is opened in the center of the sliding platform 2. The third bracket 24 and the lifting support plate 25 are mainly used to connect the sliding platform 2 and the hand-cranked digital display platform 26, and the rectangular hole in the center of the sliding platform 2 is mainly for the convenience of installing the ship model lifting bracket 23.

[0034] like Figure 1-Figure 5As shown, the hand-cranked digital display platform 26 consists of a rotating handle, a displacement digital display device and a lifting bracket 23. The hand-cranked digital display platform 26 is installed on the lifting support plate 25 of the sliding platform 2 and is located at the center. The lifting bracket 23 passes through the rectangular hole in the center of the sliding platform 2 and a ship model is installed at the bottom. The ship speed control motor 22 is installed on the right side of the sliding platform 2 and is connected to the screw coupling gear 16. The forward speed of the sliding platform 2 is controlled by the screw. The hand-cranked digital display platform 26 can adjust the displacement digital display device under the action of the screw by rotating the rotating handle. The ship speed control motor 22 mainly controls the forward speed of the sliding platform 2 through the cooperation of the screw coupling gear 16 and the rack screw.

[0035] like Figure 1-Figure 5 and Figure 7 As shown, a second bracket 21 is installed at the bottom of the propeller speed control motor 27, and the second bracket 21 is installed on the top of the lifting bracket 23, and the propeller speed control motor 27 is connected to the ship model through a supporting steel plate. The propeller speed control motor 27 is connected to the propeller at the tail of the ship model using components such as a rotating shaft 31, a winding coupling 32 and a right-angle coupling 33 to control the propeller speed. The second bracket 21 is used to connect the propeller speed control motor 27 and the lifting bracket 23 so that the two can be lifted and lowered synchronously, and the propeller speed control motor 27 can control the propeller speed at the tail of the ship model through the connection of the rotating shaft 31, the winding coupling 32 and the right-angle coupling 33.

[0036] like Figure 2 As shown, the outside of the digital display control box 4 for ship speed and rotation speed is provided with two control switches 41, a digital display propeller rotation speed controller 42, and a digital display ship speed controller 43. The two control switches 41 are mainly used to control the start and stop of the ship speed control motor 22 and the propeller rotation speed control motor 27. The digital display propeller rotation speed controller 42 and the digital display ship speed controller 43 are mainly used to adjust the parameters of the propeller rotation speed control motor 27 and the ship speed control motor 22.

[0037] like Figure 1-Figure 6 As shown, the sliding device is composed of a sliding rod device and a rack screw device, and the sliding rod device and the rack screw device are respectively installed on both sides of the top of the water tank support frame 1, the length of the sliding rod device and the rack screw device are both 0.4m and the width is 0.02m, and the sliding rod device and the screw device are nested with the sliding rod coupling sleeve and the screw coupling gear 16 at the bottom of the sliding platform 2. The fully enclosed cable threading trough is opened on the inner wall of the water tank support frame 1 and the connecting line of the ship model is embedded inside. The sliding device is composed of a sliding rod device and a rack screw device, and a sliding rod is installed on the left longitudinal beam of the water tank fixing frame. A sliding rod and a rack screw are respectively installed on the left longitudinal beam from left to right. The length of the sliding rod and the screw are both 0.4m and the width is 0.02m, which can ensure the smooth operation of the sliding platform 2.

[0038] like Figure 1-Figure 5 As shown, the main multifunctional measuring bracket 5 in the multifunctional measuring frame is made of four 1.5m long and eight 0.6m long aluminum alloy profiles, the main body bottom plate 51, the laser bottom plate 52, and the camera bottom plate 53 are all composed of aluminum alloy plates with a length of 0.93m, a width of 0.6m and a thickness of 8mm, and the main body bottom plate 51, the laser bottom plate 52 and the camera bottom plate 53 are sequentially installed on the inner side of the multifunctional measuring bracket 5 from bottom to top, the camera adjustment tray 54 is composed of a threaded rotating bracket and two square panels with a length of 0.297m, and the vertical height can be adjusted to 0.2m, and the lower square panel is fixed on the top of the camera bottom plate 53, and the upper square panel and the PIV high-speed camera 55 are connected with the PLIF high-speed camera 56, the main body bottom plate 51, the laser bottom plate 52 and the camera bottom plate 53 are mainly used for installing the main body, the laser and the camera, and the camera adjustment tray 54 is used to install the two high-speed cameras on the camera bottom plate 53, and the height is adjustable.

[0039] like Figure 1-Figure 5 As shown, the laser corner device extension frame 6 is installed on two vertical profiles in the middle of the multifunctional measuring bracket 5, and the laser corner device extension frame 6 can be adjusted up and down in the height direction. The laser corner base plate 62 is fixed on the top of the laser corner device extension frame 6, and the laser corner support plate 61 is installed on the top of the laser corner base plate 62 for fixing the laser 45° corner mirror 63. The laser 45° corner mirror 63 is composed of a triangular profile with a length of 0.2m and a side length of 50mm and a reflector with a length of 0.2m and a width of 0.15m. The height-adjustable laser corner device extension frame 6 cooperates with the laser corner base plate 62 and the laser corner support plate 61 to install the laser 45° corner mirror 63, and the laser 45° corner mirror 63 is used to reflect the laser beam.

[0040] like Figure 1-Figure 5As shown, the high-speed cameras in the high-frequency and high-precision PIV&PLIF measurement system are respectively a PIV high-speed camera 55 and a PLIF high-speed camera 56. The PIV high-speed camera 55 is equipped with a 532nm narrow-band filter in front of it, which allows light with a wavelength of 512-550nm to pass through, and can effectively block the fluorescence released by the fluorescent dye from passing through the lens. The PLIF high-speed camera 56 is equipped with a long-wave pass filter with a cut-off wavelength of 550nm to filter out the laser. The collected images are in 8-bit BMP format. The camera and the computer communicate with each other in a local area network built with Ethernet to realize image data transmission. The high-energy continuous laser is a 2W semiconductor continuous laser with a wavelength of 532nm. The sheet light has a thickness of about 1mm. The time synchronizer is used to simultaneously collect images of the PIV high-speed camera 55 and the PLIF high-speed camera 56. The PIV and PLIF concentration fields are calculated by self-programming. The PIV high-speed camera 55 uses the Qianyanlang X150 high-speed camera with a resolution of 2560×1920 pixels and a full-frame frame rate of 2000Hz. The camera memory is divided into 64G. The camera is equipped with a Nikon 50mmf / 1.8D lens. The PIV high-speed camera 55 is equipped with a 532nm narrow-band filter in front, which allows light with a wavelength of 512-550nm to pass through, and can effectively block the fluorescence released by the fluorescent dye from passing through the lens. The PLIF high-speed camera 56 also uses the Qianyanlang X 150 high-speed camera, with a resolution of 2560x 1920 pixels, a full-frame frame rate of 2000Hz, and a camera memory of 64G. The camera is equipped with a Nikon 50mmf / 1.8D lens. The PLIF high-speed camera 56 is equipped with a long-wave pass filter with a cut-off wavelength of 550nm to filter out the laser. The collected images are in 8-bit BMP format. The camera and computer communicate using a local area network built on Ethernet to achieve image data transmission.

[0041] The method of use and working principle of the device: When in use, first install the rectangular glass water tank 11 in the water tank support frame 1, then assemble the ship model control system, first install the propeller speed, hand-cranked digital display slide, ship speed control motor 22 and other equipment on the sliding platform 2, and then install the sliding platform 2 on the fixed frame between the water tank support frame 1 and the glass water tank 11, so that the slide rod and the screw device are engaged, and then the 3D printed ship model and propeller are connected to the right-angle coupling 33, and then the right-angle coupling 33 is connected to the propeller speed control motor 27 through the winding coupling 32. The rotating end of the water model is connected and fixed with the lifting bracket 23 by thread. The digital display control box 4 for ship speed and rotation speed is installed to the outer side of the water tank support frame 1 and then the power is turned on. The next step is to level the water tank, determine the position of the experimental water tank, lock the universal wheel 13 at the bottom of the water tank support frame 1, and use the level to fine-tune the water tank to keep the four corner points of the water tank at the same elevation and keep the water tank level. The next step is to determine the test stage and clarify the test section of the indoor water tank. The multifunctional measuring bracket 5 is specified to be in the appropriate position of the test section. The next stage is to install the measuring equipment according to the length, width and height of the indoor test water tank.

[0042] The main frame structure is adjusted, and the main body bottom plate 51, the laser bottom plate 52, and the camera bottom plate 53 are adjusted to the appropriate heights. The camera three-axis camera adjustment tray 54 is installed on the camera bottom plate 53. The laser corner device extension frame 6 is installed in the middle of the front of the main aluminum alloy frame, and its front end extends to the bottom of the test water tank. The laser corner bottom plate 62 and the laser corner support plate 61 are installed at the front end of the laser corner device extension frame 6. The laser 45° corner mirror 63 is installed on the laser corner support plate 61 to reflect the horizontal incident laser into a vertical plane laser. Then the laser is adjusted, the laser is installed, and the laser is installed on the laser three-axis camera adjustment tray 54. The laser three-axis adjustment tray is adjusted to the horizontal position, and the height of the tray is adjusted. The horizontal bubble on the adjustment tray is observed. The laser three-axis adjustment tray is adjusted to the horizontal position. The horizontal fan-shaped light emitted by the laser is incident on the laser 45° angle mirror 63 to form a vertical fan-shaped light. The light passes through the glass bottom plate of the water tank to illuminate the particles in the water. The next step is to install the PIV high-speed camera 55 and the PLIF high-speed camera 56, install the high-speed camera on the three-axis camera adjustment tray 54, adjust the height of the tray, observe the horizontal bubble on the adjustment tray, adjust the three-axis camera adjustment tray 54 to the horizontal position, and use the high-speed camera to take pictures of the water body illuminated by the laser. Then, the high-speed camera is connected to the computer for real-time adjustment. The camera imaging plane is made to coincide with the laser plane, and the images of the particles illuminated by the laser and the fluorescent liquid in the water body are clearly captured. Then, the time synchronizer is adjusted to synchronously capture the images of the PIV high-speed camera 55 and the PLIF high-speed camera 56. Different fluorescent dye dosages are used to calibrate the fluorescent dye concentration field in the water tank. In the next stage of experimental liquid preparation, a saline solution is placed on the left side of the gate diaphragm 14, and an ethanol solution of the same water depth is placed on the right side of the gate diaphragm 14. Tracer particles are added to the saline solution, and fluorescent dye and tracer particles are added to the ethanol solution, so that the particle concentration, fluorescent dye concentration, and the refractive index of the saline and ethanol solutions are all measured. According to the requirements, the test data is measured in the next stage. After the gate diaphragm 14 is opened, the salt water heterogeneous flow begins to move upward along the bottom of the ethanol solution. At the same time, the switches of the ship model forward and the propeller rotation are turned on, and the particle image and the fluorescent dye image are collected synchronously. The PIV flow field calculation program is used to obtain the two-dimensional velocity field, and the PLIF concentration field calculation program is used to obtain the two-dimensional salinity field. It is used to analyze the turbulent characteristics and concentration distribution characteristics of the water flow structure of the salt-fresh mixed movement under the influence of ship motion and propeller disturbance. The ship model control system can flexibly adjust the forward speed, match the corresponding propeller speed, digitally display the speed results, and automatically adjust the draft of the ship model, ensuring the feasibility of the mechanism test.

[0043] Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A test and measurement system suitable for studying the influence of ship navigation on density flow, comprising a rectangular glass water tank (11), a movable water tank support frame (1), a ship control system with power traction and propeller speed synchronization, a multifunctional measurement frame and a high-frequency and high-precision PIV & PLIF measurement system, characterized in that: The glass water tank (11) is made of quartz glass, four first brackets (12) are installed near the bottom of the water tank support frame (1), universal wheels (13) are installed at the bottom of the first bracket (12), and the top of the water tank support frame (1) is installed and fixed via a connecting frame and the glass water tank (11); The ship model control system with synchronized power traction and propeller speed is composed of a sliding platform (2), a hand-cranked digital display platform (26), a ship speed control motor (22), a propeller speed control motor (27), a propeller rotation connection component, a ship speed and speed digital display control box (4), a sliding device and a fully enclosed cable threading trough; The multifunctional measuring frame is 0.93 m long, 0.60 m wide and 1.50 m high, and is composed of a main multifunctional measuring bracket (5), a main machine bottom plate (51), a laser bottom plate (52), a camera bottom plate (53), a camera adjustment tray (54), a laser corner device extension frame (6), a laser corner bottom plate (62), a laser corner support plate (61) and a laser 45° corner mirror (63); The high-frequency and high-precision PIV&PLIF measurement system consists of two high-speed cameras, a high-energy continuous laser, a time synchronizer and a PIV flow field / PLIF concentration field calculation program.

2. A test and measurement system suitable for studying the influence of ship navigation on density flow according to claim 1, characterized in that: The rectangular glass water tank (11) is 4.5m long, 0.3m wide and 0.3m high. A gate partition (14) for separating salt water and fresh water is arranged inside the glass water tank (11) at a position 1.6m away from the left side of the water tank. Both ends of the gate partition (14) are embedded with a water stop strip with a depth of 10mm and a width of 3.5mm.

3. A test and measurement system suitable for studying the influence of ship navigation on density flow according to claim 2, characterized in that: The sliding platform (2) is composed of a steel main board with a length of 0.64m and a width of 0.4m. A third bracket (24) is symmetrically fixedly connected to the top of the sliding platform (2). A lifting support plate (25) is fixedly connected between the outer surfaces of the two third brackets (24). Four sliding rod coupling sleeves (15) are arranged at the bottom of the sliding platform (2). A screw coupling gear (16) is installed at the top of the sliding platform (2) near the right side. A rectangular hole is opened in the center of the sliding platform (2).

4. A test and measurement system suitable for studying the influence of ship navigation on density flow according to claim 3, characterized in that: The hand-cranked digital display platform (26) is composed of a rotating handle, a displacement digital display device and a lifting bracket (23). The hand-cranked digital display platform (26) is installed on the lifting support plate (25) of the sliding platform (2) and is located at the center. The lifting bracket (23) passes through the rectangular hole at the center of the sliding platform (2) and a ship model is installed at the bottom. The ship speed control motor (22) is installed on the right side of the sliding platform (2) and is connected to the screw coupling gear (16). The forward speed of the sliding platform (2) is controlled by the screw.

5. A test and measurement system for studying the influence of ship navigation on density current according to claim 4, characterized in that: A second bracket (21) is installed at the bottom of the propeller speed control motor (27), and the second bracket (21) is installed on the top of the lifting bracket (23). The propeller speed control motor (27) is connected to the ship model through a supporting steel plate. The propeller speed control motor (27) is connected to the propeller at the tail of the ship model using components such as a rotating shaft (31), a winding coupling (32) and a right-angle coupling (33) to control the propeller speed.

6. A test and measurement system for studying the influence of ship navigation on density current according to claim 5, characterized in that: The ship speed and rotation speed digital display control box (4) is provided with two control switches (41), a digital display propeller rotation speed controller (42), and a digital display ship speed controller (43) outside.

7. A test and measurement system for studying the influence of ship navigation on density current according to claim 6, characterized in that: The sliding device is composed of a sliding rod device and a rack screw device, and the sliding rod device and the rack screw device are respectively installed on both sides of the top of the water tank support frame (1), the sliding rod device and the rack screw device are both 0.4m long and 0.02m wide, and the sliding rod device and the screw device are nested with the sliding rod coupling sleeve and the screw coupling gear (16) at the bottom of the sliding platform (2), and the fully enclosed cable threading groove is opened on the inner wall of the water tank support frame (1) and the connecting wire of the ship model is embedded inside.

8. A test and measurement system for studying the influence of ship navigation on density current according to claim 7, characterized in that: The main multifunctional measuring bracket (5) in the multifunctional measuring frame is made of four 1.5m long and eight 0.6m long aluminum alloy profiles, the main body bottom plate (51), the laser bottom plate (52) and the camera bottom plate (53) are all made of aluminum alloy plates with a length of 0.93m, a width of 0.6m and a thickness of 8mm, and the main body bottom plate (51), the laser bottom plate (52) and the camera bottom plate (53) are sequentially installed on the inner side of the multifunctional measuring bracket (5) from bottom to top, the camera adjustment tray (54) is composed of a threaded rotating bracket and two square panels with a length of 0.297m, the vertical height can be adjusted to 0.2m, and the lower square panel is fixed on the top of the camera bottom plate (53), and the upper square panel and the PIV high-speed camera (55) are connected with the PLIF high-speed camera (56).

9. A test and measurement system for studying the influence of ship navigation on density current according to claim 8, characterized in that: The laser corner device extension frame (6) is installed on two vertical profiles in the middle of the multifunctional measuring bracket (5), and the laser corner device extension frame (6) can be adjusted up and down in the height direction. The laser corner base plate (62) is fixed on the top of the laser corner device extension frame (6). The laser corner support plate (61) is installed on the top of the laser corner base plate (62) for fixing and installing a laser 45° corner mirror (63). The laser 45° corner mirror (63) is composed of a triangular profile with a length of 0.2m and a side length of 50mm and a reflector with a length of 0.2m and a width of 0.15m.

10. A test and measurement system for studying the influence of ship navigation on density current according to claim 9, characterized in that: The high-speed cameras in the high-frequency and high-precision PIV&PLIF measurement system are respectively a PIV high-speed camera (55) and a PLIF high-speed camera (56). The PIV high-speed camera (55) is equipped with a 532nm narrow-band filter in front of it, which allows light with a wavelength of 512-550nm to pass through, and can effectively block the fluorescence released by the fluorescent dye from passing through the lens. The PLIF high-speed camera (56) is equipped with a long-wave pass filter with a cut-off wavelength of 550nm to filter out the laser. The collected images are all in 8-bit BMP format. The camera and the computer communicate with each other in a local area network built by Ethernet to realize image data transmission. The high-energy continuous laser is a 2W semiconductor continuous laser. The laser is a sheet of light with a wavelength of 532nm and a thickness of about 1mm. The time synchronizer is used to simultaneously collect images of the PIV high-speed camera (55) and the PLIF high-speed camera (56). The PIV and PLIF concentration fields are calculated by autonomous programming.

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