A high-speed experimental water tunnel

Abstract

The present application relates to the technical field of hydrodynamics experiment, especially to a high-speed experimental water tunnel, comprising a gas-water separation mechanism for separating gas in circulating water, an experimental device connected with the gas-water separation mechanism for accelerating circulating water flow, a slow-down mechanism in the gas-water separation mechanism, comprising a blocking plate and a combined support rod, the blocking plate being used for relieving flow speed, the combined support rod supporting the blocking plate to stretch and contract with flow speed, a displacement monitoring mechanism detecting endpoint displacement angle of the blocking plate, and a data acquisition module collecting air pressure and flow speed data in the experimental device after acceleration. A data analysis module determines target pump speed by adjusting initial pump speed according to pressure and flow speed data, and a control module feeds back and adjusts target pump speed according to comparison result of actual displacement rate and standard interval. The present application sets a device capable of effectively relieving water flow speed of circulating water in the high-speed water tunnel when accelerating, reduces turbulence occurrence, and improves detection efficiency of the high-speed water tunnel.

Description

Technical Field

[0001] The present invention relates to the technical field of hydrodynamic experiments, in particular to a high-speed experimental water tunnel. Background Art

[0002] A high-speed water tunnel is a crucial instrument used for hydrodynamic testing in the fields of natural science, engineering, and technology. Its core functions include testing the hydrodynamic parameters of underwater vehicles, flow noise, and cavitation noise, as well as displaying the flow field around the tunnel. A high-speed water tunnel is a water circulation system in which the flow rate and pressure can be independently controlled. The experimental section of the tunnel can be circular or rectangular in cross-section. Observation windows are located at the top, bottom, front, and rear of the tunnel. Unlike a towing tank, the test object moves through the tunnel, but controlled circulating water. During cavitation experiments in a water tunnel, clusters of bubbles are generated in the experimental section. To prevent these bubbles from circulating back into the experimental section, the tunnel must be of a certain height, allowing them to dissipate through a longer loop and higher pressure zone. Alternatively, a specialized dissolver can be installed to dissolve the bubbles in water.

[0003] Chinese Patent Publication No.: CN118999999A discloses a water-gas separation device and a cavitation water tunnel experimental system. The water-gas separation device includes a tank body and a water-gas separation module. The tank body is provided with a liquid inlet and a liquid outlet. The water-gas separation module includes at least one water-gas separation unit; the water-gas separation unit includes a bubble collection pipe and a plurality of water-gas separation plates arranged at intervals along a second direction. The end of the water-gas separation plate is provided with a guide edge, and the guide edge includes a first bending portion arranged along a third direction and a second bending portion arranged along a fourth direction. The first side of the first bending portion is connected to the water-gas separation plate, and the second side of the first bending portion is connected to the first side of the second bending portion. A bubble collection space is formed between the first bending portion and the second bending portion, and the bubble collection space is connected to the bubble collection pipe.

[0004] It can be seen that the existing technology has the following problems: when the circulating water in the high-speed water tunnel is accelerated, due to the lack of a device in the high-speed experimental water tunnel that can effectively alleviate the water flow velocity, when water flow disturbance occurs, it takes time to recover or the object to be tested needs to be removed, thereby reducing the efficiency of high-speed water tunnel detection. Summary of the Invention

[0005] To this end, the present invention provides a high-speed experimental water tunnel experimental device to overcome the problem in the prior art that due to the lack of a device that can effectively alleviate the water flow velocity in the high-speed experimental water tunnel, when water flow disturbance occurs, it takes time to recover or the object to be tested needs to be removed, thereby reducing the efficiency of high-speed water tunnel detection.

[0006] To achieve the above-mentioned purpose, the present invention provides a high-speed experimental water tunnel, comprising:

[0007] Gas-water separation mechanism, used to separate gas from circulating water;

[0008] An experimental device, which is connected to the gas-water separation mechanism and is provided with a contraction section capable of accelerating the flow rate of circulating water;

[0009] a deceleration mechanism, which is arranged in the gas-water separation mechanism and is used to adjust the flow rate of the circulating water, comprising a baffle and a combined support rod, wherein the baffle is used to slow down the flow rate of the circulating water, and the combined support rod is used to support the baffle and can be extended and retracted according to the flow rate of the circulating water;

[0010] a displacement monitoring mechanism, which is provided at the end point of the arresting plate and is used to detect the actual displacement angle of the end point of the arresting plate;

[0011] A data acquisition module, used to collect pressure data and water flow velocity data in the experimental device;

[0012] a data analysis module, connected to the gas-water separation mechanism, the experimental device, the displacement monitoring mechanism, and the data acquisition module, respectively, for determining whether the initial pumping speed of the pump body in the first water delivery pipe needs to be adjusted to obtain a target pumping speed based on the pressure data and the water flow rate data;

[0013] a control module, connected to the data analysis module, configured to determine an actual displacement rate based on the actual displacement angle and a detection period of the displacement monitoring mechanism, compare the actual displacement rate with a standard displacement rate interval to obtain a displacement rate comparison result, and determine whether to perform feedback adjustment on the target pump speed based on the displacement rate comparison result;

[0014] The pressure data is the air pressure in the experimental device; the water flow rate data is the circulating water flow rate after acceleration.

[0015] Furthermore, the gas-water separation mechanism includes:

[0016] The gas-water separation mechanism comprises:

[0017] The tank body is provided with an upper cutout and a lower cutout, wherein the upper cutout is connected to the first air pressure device, the lower cutout is connected to the lower water tank, and the lower water tank is connected to the experimental device through a second elbow;

[0018] a partition disposed inside the tank body and connected to the inner wall of the tank body to form a closed space with an open upper end;

[0019] Wherein, an inlet grille plate is provided at the opening of the partition, and a deceleration mechanism is provided inside the inlet grille plate.

[0020] Furthermore, the experimental device includes:

[0021] A partitioned water tank is provided in the experimental device and is provided with a partition plate, wherein the partition plate is provided with a cutout for circulating water in the partitioned water tank;

[0022] a venturi tube, which is arranged on the upper part of the partitioned water tank;

[0023] The second air pressure device is arranged on the upper part of the partitioned water tank and is used to adjust the air pressure in the upper layer of the partitioned water tank.

[0024] Furthermore, the data acquisition module includes:

[0025] a first data acquisition unit, configured to acquire a pressure value of the front section of the contraction section;

[0026] a second data acquisition unit, configured to acquire a pressure value of the rear section of the contraction section;

[0027] The detection unit detects whether the pressure value at the cross section of the rectifier tube meets the standard according to the front section pressure; and detects whether the pressure value at the throat section meets the standard according to the rear section pressure.

[0028] Furthermore, the data analysis module is used to determine the actual circulating water flow rate at the throat according to the pressure data of the front section pressure and the rear section pressure and the comprehensive influence coefficient;

[0029] The comprehensive influence coefficient is determined according to the fluid density, the cross-sectional area at the rectifier tube cross section, and the cross-sectional area at the throat cross section.

[0030] Furthermore, the data analysis module is used to compare the actual circulating water flow rate with the standard circulating water flow rate to obtain a circulating water flow rate comparison result, and determine whether to adjust the initial pump speed according to the circulating water flow rate comparison result;

[0031] The standard circulating water flow rate is determined according to the fluid dynamics parameters of the object to be detected in the high-speed experimental water tunnel.

[0032] Furthermore, the data analysis module is used to determine a circulating water flow rate influence coefficient based on the pressure data and the water flow rate data, and to adjust the initial pump speed based on the circulating water flow rate influence coefficient.

[0033] Furthermore, the displacement monitoring mechanism monitors the actual displacement angle of the end point of the barrier plate at a preset time interval, and the data analysis module calculates the actual displacement rate based on the actual displacement angle difference and time interval of adjacent cycles.

[0034] Furthermore, the control module compares the actual displacement rate with the standard displacement rate interval to obtain a displacement rate comparison result, and determines whether to perform feedback adjustment on the target pump speed based on the displacement rate comparison result.

[0035] Further, the control module is used to feedback adjust the target pump speed according to the displacement rate ratio result, or keep the target pump speed unchanged.

[0036] Compared with the prior art, the beneficial effects of the present application are that the gas-water separation mechanism is used to replace the multiple inflection point positions of the high-speed experimental water tunnel, the tank body is expanded to break through the volume limit and increase the pressure bearing capacity of the gas-water separation mechanism, and after the volume of the tank body is increased, the contact area of the liquid surface with the low-pressure environment is increased, the degassing efficiency is improved, the degassing time is shortened, and the degassing amount is increased.

[0037] Further, to avoid the problem that the change of the tunnel structure increases the turbulence degree of the circulating water flow field, a speed reduction mechanism is installed at the outlet position of the tank body circulating water for controlling the flow rate of the circulating water, the gas-water separation mechanism is combined with the experimental device to reduce the test cost and improve the test accuracy.

[0038] Further, double-point monitoring avoids single-point error and ensures the reliability of pressure data, thereby ensuring the accuracy of subsequent flow rate calculation, in the embodiment, the flow rate and pressure are used to maintain the circulating water flow rate in a preset standard range, realize closed-loop control of experimental conditions, prevent detection data deviation caused by abnormal pressure, and improve the repeatability and reliability of experimental results. Using mature fluid mechanics theory, the theoretical accuracy of flow rate calculation is ensured, the limitations of empirical formula are avoided, key parameters such as fluid density and cross-sectional contraction ratio are included in the unified calculation framework, the flow rate result reflects the influence of pressure difference and geometric structure at the same time, the universality and precision of the calculation model are improved. Dynamic balance of experimental parameters is realized, manual intervention is reduced, different detection materials are adapted to the fluid environment, and experimental efficiency is improved.

[0039] Further, the flow rate fluctuation is controlled within a very small range to meet the demand of high-precision fluid dynamics experiment; the pressure data and flow rate difference value are fused to avoid the limitation of single parameter adjustment; the upper limit threshold of flow rate is set to prevent equipment damage and experimental accidents; the initial pump speed adjustment path is optimized to reduce energy consumption and prolong equipment life.

[0040] Furthermore, the influence coefficient is constructed by combining the Bernoulli equation with real-time data, which not only retains the theoretical basis but also adapts to the nonlinear characteristics of the system. At the same time, pressure fluctuations and flow rate deviations are taken into account to avoid the limitations of single-parameter control. The adjustment coefficient can be optimized online according to the equipment characteristics and operating conditions to achieve the flexibility of the control system, so that it can achieve a dynamic response without shock, mutation, or continuous stability during parameter adjustment or external disturbance response. For the case where the actual displacement rate is less than the minimum value of the standard displacement rate interval, the initial pump speed is increased according to the difference between the actual displacement rate and the minimum value of the standard displacement rate interval. This can avoid the reduction of the efficiency of the high-speed water tunnel experiment due to the slow circulating water flow rate. For the case where the actual displacement rate is greater than the maximum value of the standard displacement rate interval, the initial pump speed is reduced according to the difference between the maximum value of the standard displacement rate interval and the actual displacement rate. This can avoid the formation of turbulence due to the excessively fast circulating water flow rate, which reduces the efficiency of the high-speed water tunnel experiment. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 This is a cross-sectional view of the main body of the high-speed experimental water tunnel gas-water separation tank in the embodiment;

[0042] Figure 2 Schematic diagram of the overall structure of the high-speed experimental water tunnel in the embodiment;

[0043] Figure 3 This is a schematic diagram of the structure of A in the overall structural diagram of the high-speed experimental water tunnel in the embodiment;

[0044] Figure 4 This is a working diagram of the high-speed water tunnel experiment in the embodiment;

[0045] Figure 5 A flowchart of the logic determination process of the high-speed experimental water tunnel control module in the embodiment;

[0046] In the figure, 1-gas-water separation mechanism; 2-experimental device; 3-retardation mechanism; 302-blocking plate; 303-combined support rod; 304-displacement monitoring mechanism; 4-tank body; 401-supporting support; 402-lower water tank; 4021-second elbow; 4022-second water pipe; 5-Venturi tube; 501-first elbow; 502-first water pipe; 503-honeycomb; 6-partitioned water tank; 601-partitioning plate; 7-first air pressure equipment; 8-second air pressure equipment; 14-inlet grille plate; 15-partitioning plate; 17-outlet grille plate. DETAILED DESCRIPTION

[0047] In order to make the objects and advantages of the present invention more clearly understood, the present invention is further described below in conjunction with embodiments; it should be understood that the specific embodiments described herein are merely used to explain the present invention and are not intended to limit the present invention.

[0048] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only used to explain the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0049] It should be noted that, in the description of the present invention, terms such as "up", "down", "left", "right", "inside", and "outside" indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings. This is only for the convenience of description and does not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation on the present invention.

[0050] Furthermore, it should be noted that, in the description of the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0051] See also Figure 1-Figure 4 As shown, Figure 1 This is a cross-sectional view of the main body of the high-speed experimental water tunnel gas-water separation tank in the embodiment; Figure 2 Schematic diagram of the overall structure of the high-speed experimental water tunnel in the embodiment; Figure 3 This is a schematic diagram of the structure of A in the overall structural diagram of the high-speed experimental water tunnel in the embodiment; Figure 4 This is a working diagram of the high-speed water tunnel experiment in the embodiment; Figure 5 4 is a process flow chart of the logic determination of the high-speed experimental water tunnel control module in the embodiment.

[0052] The present invention provides a high-speed experimental water tunnel, comprising:

[0053] Gas-water separation mechanism 1, used to separate gas from circulating water;

[0054] Experimental device 2, which is connected to the gas-water separation mechanism and is provided with a contraction section capable of accelerating the flow rate of circulating water;

[0055] The deceleration mechanism 3 is provided in the gas-water separation mechanism and is used to adjust the circulating water flow rate. The deceleration mechanism 3 includes a baffle plate 302 and a combined support rod 303. The baffle plate reduces the circulating water flow rate. The combined support rod is used to support the baffle plate so that it can be extended and retracted according to the circulating water flow rate. The combined support rod includes a first support rod and a second support rod. The diameter of the first support rod is larger than the diameter of the second support rod. The two support rods are connected by a slide rail. A spring is provided under the second support rod. When the circulating water flow rate exceeds the spring force, the combined support rod contracts due to the impact of the water flow, absorbing a portion of the kinetic energy of the water flow to slow the water flow rate. When the circulating water flow rate is less than the spring force, the combined support rod returns to its original position.

[0056] a displacement monitoring mechanism 304, which is provided at the end point of the arresting plate and is used to detect the actual displacement angle of the end point of the arresting plate;

[0057] A data acquisition module, used for collecting pressure data and water flow velocity data in the experimental device;

[0058] a data analysis module, connected to the gas-water separation mechanism, the experimental device, the displacement monitoring mechanism, and the data acquisition module, respectively, and determining whether the initial pump speed needs to be adjusted to obtain a first pump speed based on the pressure data and the water flow rate data;

[0059] a control module, connected to the data analysis module, configured to determine an actual displacement rate based on the actual displacement angle and a detection period of the displacement monitoring mechanism, compare the actual displacement rate with a standard displacement rate interval to obtain a displacement rate comparison result, and determine whether to perform feedback adjustment on the target pump speed based on the displacement rate comparison result;

[0060] Among them, the pressure data is the air pressure in the experimental device; the water flow rate data is the circulating water flow rate after acceleration; and the overall device refers to a device for conducting high-speed experiments.

[0061] By replacing the gas-water separation mechanism at multiple inflection points of the high-speed experimental water tunnel and expanding the tank body, the pressure bearing capacity of the gas-water separation mechanism is increased, and the contact area between the liquid surface and the low-pressure environment is increased after the tank body volume is increased, which can improve the degassing efficiency, shorten the degassing time, and increase the degassing volume.

[0062] In order to avoid the problem of increased turbulence in the circulating water flow field due to changes in the cavern structure, a retarder mechanism is installed at the circulating water outlet of the tank to control the flow rate of the circulating water. The air-water separation mechanism is combined with the experimental device to reduce the test cost and improve the test accuracy.

[0063] The gas-water separation mechanism 1 comprises:

[0064] The tank body 4 is used to form a closed flow channel space and is provided with an upper cutout and a lower cutout. The upper cutout is connected to the first air pressure device, and the lower cutout is connected to the lower water tank. The lower water tank is connected to the experimental device through the second elbow to remove gas from the circulating water.

[0065] a partition 15 disposed inside the tank body 4 and connected to the inner wall of the tank body 4 to form a closed space with an open upper end;

[0066] The opening of the partition 15 is provided with an inlet grille plate 14, inside of which a retarding mechanism 3 is provided;

[0067] The first air pressure device 7 is used to adjust the flow rate of the circulating water;

[0068] Tank 4, used to remove gas from circulating water;

[0069] The lower water tank 402 is used to eliminate turbulence generated during the circulation of the circulating water;

[0070] An experimental device 2, which is provided with a contraction section for accelerating the flow rate of circulating water, and is connected to the gas-water separation mechanism 1;

[0071] The experimental setup includes,

[0072] A partitioned water tank 6 is provided in the experimental device and has a partition plate 601 therein. The partition plate 601 has a cutout for circulating water in the partitioned water tank;

[0073] The venturi tube 5 is provided on the upper part of the partitioned water tank to provide support for detecting the flow rate of the circulating water;

[0074] The second air pressure device 8 is arranged on the upper part of the partitioned water tank 6 and is used to adjust the air pressure in the upper layer of the partitioned water tank 6 .

[0075] Data acquisition module, including,

[0076] a first data acquisition unit composed of a plurality of sensors for acquiring the pressure before the contraction section of the experimental device;

[0077] a second data acquisition unit composed of a plurality of sensors for acquiring the pressure after the contraction section of the experimental device;

[0078] a data analysis module, connected to the first data acquisition unit and the second data acquisition unit, respectively, for calculating a real-time circulating water flow rate based on the pressure value before the contraction section acquired by the second data acquisition unit and the pressure value after the contraction section acquired by the second data acquisition unit;

[0079] The control module is connected to the gas-water separation mechanism, the experimental device and the data analysis module respectively, and is used to adjust the experimental device according to the information output by the data analysis module to change the flow rate of the circulating water; and adjust the target pump speed according to the actual displacement angle.

[0080] The first air pressure device provided on the tank body and the data analysis module are respectively connected to each other and are used to adjust the working power of the first air pressure device according to the analysis result of the data analysis module so as to adjust the flow rate of the circulating water to a stable state.

[0081] The working process of the high-speed experimental water tunnel includes:

[0082] Step S1: Check the equipment and modules in the high-speed circulating water tunnel and set parameters such as flow rate, pressure, and temperature according to experimental requirements;

[0083] Step S2: inject ionized water or distilled water into the high-speed experimental water tunnel, start the water pump, gradually increase the flow rate to the level required for the experiment, wait for the water flow to stabilize, and ensure that there are no bubbles or eddy currents;

[0084] Step S3, collecting data at a set flow rate, the data including water flow rate, pressure distribution, pump speed, and output power, adjusting the flow rate as needed, and repeating the experiment;

[0085] Step S4, processing the collected data, filtering and denoising the data, flow field analysis, and analyzing the circulating water velocity, pressure distribution, and eddy current;

[0086] Step S5, gradually reduce the flow rate, turn off the water pump, perform equipment maintenance, drain the water hole, clean the equipment, and check the sensors and data acquisition system.

[0087] Specifically, the gas-water separation mechanism also includes:

[0088] The tank body 4 is provided with an upper cutout, a lower cutout, and a side cutout on the side. The upper cutout is connected to the external first air pressure device, and the lower cutout is used to introduce a water source into the tank body. A partition 15 is provided inside the tank body 4, wherein the partition forms a pipe-sealed space with the inner wall of the tank body 4, and the opening direction is upward. The inlet grid plate 14 is welded at the opening of the partition 15, and a deceleration mechanism 3 is provided inside the partition. The outlet grid plate 17 is welded at the side cutout, wherein the deceleration mechanism includes a blocking plate 302 and a combined support rod 303.

[0089] The supporting support 401 is provided with a plurality of triangular supports connected around the tank body 4 for supporting the tank body 4;

[0090] A lower water tank 402 is provided below the tank body 4 and is connected to the lower cutout. When the horizontal surface in the lower water tank 402 is flush with the lower cutout, circulating water is injected into the tank body 4 from the lower cutout.

[0091] The lower water tank 402 can store circulating water. The tank body 4 can introduce circulating water through the lower cutout. The circulating water is pumped into the tank body from the lower end. The water level gradually rises to the opening of the partition 15. The water flows through the inlet grid plate 14, through the closed pipe formed by the partition 15 and the inner wall of the tank body, and is guided by the retarding mechanism 3. After that, it passes through the outlet grid plate 17 and enters the entrance of the rectifying section.

[0092] Due to the above structural advantages, the pressure bearing, degassing volume and time consumption of the gas-water separation mechanism are no longer limited by the volume of the water hole, and can meet the requirements for high flow field quality.

[0093] The second elbow 4021 in the lower water tank 402 has a bending angle of 90 degrees and an opening facing upward. The second elbow 4021 is connected to the second water pipe 4022 to convey circulating water and change the direction of the circulating water.

[0094] The second elbow 4021 makes the circulating water direction parallel to the direction of the circulating water introduced into the lower inclined port upward, reducing the influence of the disturbance caused by the initial velocity of the liquid outflow on the liquid stability, making the liquid stable and reducing turbulence.

[0095] Specifically, the experimental device includes:

[0096] The partitioned water tank 6 is arranged on the right side of the tank body. A partition plate 601 is welded in the middle of the partitioned water tank to divide it into upper and lower layers. A notch is provided in the middle of the partition plate 601. The upper layer of the partitioned water tank is provided with an upper side notch and an upper upper notch, and the lower layer of the partitioned water tank is provided with a lower side notch.

[0097] A venturi tube 5 is provided at the cutout of the upper side, and circulating water is transported from the tank body 4 through the venturi tube to the partitioned water tank 6;

[0098] A second air pressure device is provided at the upper cutout of the upper layer, which is used to control the air pressure in the upper layer of the partitioned water tank. Controlling the air pressure in the upper layer of the water tank can compensate for the pressure loss of the water flow during the circulation process by adjusting the gas pressure, thereby avoiding unstable flow rate due to pressure fluctuations. The upper and lower layers of the partitioned water tank are connected through the partition cutout. The height of the liquid level in the upper layer will directly affect the output pressure of the water flow in the lower layer. The greater the liquid level difference, the greater the static pressure. Controlling the air pressure in the upper layer can indirectly adjust the stability of the upper layer liquid level. When the air pressure rises, the pressure of the gas on the water surface increases, which may cause the upper water level to drop or remain stable, thereby controlling the output of the lower layer water flow through the partition cutout to ensure the consistency of the circulation flow rate of the water tunnel.

[0099] The second water supply pipe 4022 is provided at the side cutout of the lower layer, and supplies circulating water to the lower water tank 402 through the lower layer of the partitioned water tank 6;

[0100] The partition cutout 15 is formed on the partition plate 601 and is used to connect the upper water tank and the lower water tank of the partitioned water tank 6, so that the circulating water in the venturi tube 5 can be transported to the lower layer of the partitioned water tank 6 without damaging the sealing of the upper layer of the partitioned water tank 6;

[0101] The upper layer of the divided water tank 6 has a free water surface, which is connected to the air pressure space in the upper layer of the divided water tank 6. The upper layer of the divided water tank 6 is connected to a second air pressure device. The second air pressure device controls the pressure in the upper layer of the divided water tank 6 by controlling the air pressure, thereby controlling the pressure at the free liquid surface of the experimental section.

[0102] The Venturi tube 5 consists of the following components: an inlet section, which is a short cylindrical section with a diameter D; a converging section, which is a tapered tube with a honeycomb device at the head for flow regulation; a throat, which is a short straight tube section with a groove on its upper surface for connecting to the air in the upper water tank; and a diffuser, which is a square tapered tube. The inlet section of the Venturi tube is connected to a reserved notch on the side of the tank body to receive the circulating water after air-water separation. The right end of the diffuser section is connected to a first elbow 501, which is connected to a first water pipe 502, which transports the circulating water from the upper layer of the partitioned water tank 6 to the lower layer.

[0103] The internal structure of the Venturi tube 5 is a gradually converging and expanding structure. When fluid passes through this tube, a localized low-pressure zone is generated in the throat area. This characteristic enables the Venturi tube to not only accurately measure the flow rate of the fluid, but also effectively control the flow state of the fluid. It has a free water surface in the upper layer of the water tank and is connected to the second air pressure device.

[0104] The circulating water within the high-speed circulating water tunnel experimental apparatus circulates independently. In this example, the circulating water in the partitioned water tank 6 is used as the initial position for describing the entire circulation process. During normal operation, the two lower water tanks are connected, with the liquid level exceeding the lower end of the lower connection pipe of the tank body 4. The circulating water in the lower layer of the partitioned water tank is first fed into the lower water tank 402 via the second water pipe 4022. After initial stabilization and reduced flow rate, the water is then introduced into the tank body 4 via the lower water tank 402. Circulating water is pumped in from the lower end of the tank body 4, and the water level gradually rises to the opening on the partition 15. It passes through the inlet grid plate 14 and the closed pipe formed by the partition 15 and the inner wall of the tank body 4. After being guided by the deceleration mechanism, it passes through the outlet grid plate 17 and enters the inlet of the rectifying section. The liquid enters the contraction section after being rectified by the honeycomb 503 of the rectifying section, and then enters the experimental section after passing through the contraction section. The free water surface in the experimental section is connected to the air pressure space in the upper layer of the divided water tank 6. The experimental section can be set with the conditions required for the experiment. After flowing through the experimental section, it enters the diffusion section, and after passing through the diffusion section, it enters the water pipe and enters the lower water tank, completing a cycle.

[0105] Since the upper end of the tank body is connected to the first air pressure device, the gas in the tank body is extracted to put the tank body in a low-pressure state. On the one hand, it provides a power source for the entire cycle, and on the other hand, the low-pressure state helps to separate the gas and water and complete the degassing process. Since the venturi tube has a gradually expanding and contracting structure, a local low-pressure area is generated in the throat area, so that the venturi tube can not only accurately measure the flow rate of the fluid, but also effectively control the flow state of the fluid. Since the second air pressure device is provided on the upper layer of the separated water tank and a free water surface is left in the experimental section, the pressure in the experimental section can be reduced when the air is extracted, and the pressure in the experimental section can be increased when the air is pumped in. Through the above functions, the multiple inflection points of the high-speed experimental water tunnel break through the volume limitation and increase the pressure bearing capacity of the gas-water separation mechanism.

[0106] Specifically, the data acquisition module includes:

[0107] a first data acquisition unit, configured to acquire a pressure value of a front section of a contraction section of the experimental device;

[0108] a second data acquisition unit, configured to acquire a pressure value of a rear section of the contraction section of the experimental device;

[0109] The detection unit detects whether the pressure value at the cross section of the rectifier tube meets the standard according to the front section pressure; and detects whether the pressure value at the throat section meets the standard according to the rear section pressure.

[0110] Specifically, the data analysis module includes:

[0111] The data analysis module determines the circulating water flow rate at the throat according to the pressure data of the front section pressure and the rear section pressure and the comprehensive influence coefficient;

[0112] The comprehensive influence coefficient is determined according to the fluid density, the cross-sectional area at the rectifier tube section, and the cross-sectional area at the throat section.

[0113] In this embodiment, the cross-sectional area of ​​the rectifier tube is measured.

[0114] A1=0.02m 2 ,

[0115] throat cross-sectional area,

[0116] A1=0.005m 2 ;

[0117] Fluid density is 1000kg / m 3 ; The front pressure p1 is,

[0118] 1.2×10 5 Pa, the pressure p2 at the throat is,

[0119] 1.0×10 5 Pa.

[0120] The throat flow velocity is calculated to be 6.55 m / s according to the Bernoulli equation and the Venturi tube flow formula. Calculating the throat flow velocity according to the Bernoulli equation and the Venturi tube flow formula is an existing technology and will not be described in detail here.

[0121] Dual-point monitoring avoids single-point errors and ensures the reliability of pressure data, thereby ensuring the accuracy of subsequent flow rate calculations. In this embodiment, the circulating water flow rate is maintained within the preset standard range through flow rate and pressure, achieving closed-loop control of experimental conditions, preventing deviations in test data due to pressure anomalies, and improving the repeatability and credibility of experimental results. Mature fluid mechanics theory is used to ensure the theoretical accuracy of flow rate calculations, avoid the limitations of empirical formulas, and incorporate key parameters such as fluid density and cross-sectional shrinkage ratio into a unified calculation framework, so that the flow rate results simultaneously reflect the influence of pressure difference and geometric structure, thereby improving the universality and accuracy of the calculation model. A dynamic balance of experimental parameters is achieved, reducing manual intervention, adapting to the requirements of different test objects for the fluid environment, and improving experimental efficiency.

[0122] Specifically, the data analysis module compares the actual circulating water flow rate with the standard circulating water flow rate and determines whether to adjust the pump speed based on the circulating water flow rate comparison result. The standard circulating water flow rate is determined based on historical relevant data. For example, suppose the laboratory has previously tested three robot models of the same type that are geometrically similar to the new robot, all of which are streamlined and of similar size. The historical experimental data is as follows:

[0123] Model A, length 1.2 meters: The circulating water flow rate used during the test was 5m / s, and the measured resistance data was stable and consistent with actual working conditions;

[0124] Model B, length 1.0 m: The circulating water flow rate used during the test was 4.5 m / s, and the experimental results matched the actual application scenario;

[0125] Model C, length 1.5 m: The circulating water flow rate used during the test was 5.8 m / s, and the data validity has been verified.

[0126] The new robot model currently under test is 1.3 meters long, similar in size to the aforementioned models and serving the same purpose. Analysis of historical data reveals that the test flow rate for this type of robot model is generally positively correlated with its length; larger models require slightly higher flow rates to simulate actual interaction with water flow. Therefore, based on this pattern and combining the flow rate ranges of Models A and C, the standard circulating water flow rate for the new robot is determined to be approximately 5.3 m / s.

[0127] The adjusted pump speed is the pump speed of the first air pressure device.

[0128] In this embodiment, the standard circulating water flow rate is set to 8m / s. If the actual circulating water flow rate is less than the standard circulating water flow rate, the adjustment amount of the pump speed is further determined by the pressure data and the difference between the actual circulating water flow rate and the standard circulating water flow rate.

[0129] If the actual circulating water flow rate is greater than or equal to the standard circulating water flow rate, the pump speed is reduced according to the difference between the actual circulating water flow rate and the standard circulating water flow rate.

[0130] Specifically, the data analysis module determines the circulating water flow rate influence coefficient according to the pressure data and the water flow rate data, and adjusts the initial pump speed according to the circulating water flow rate influence coefficient.

[0131] Calculate the circulating water flow rate influence coefficient based on the real-time pressure data and water flow rate data of the pressure sensor, and determine the circulating water flow rate influence coefficient by multiplying the pressure fluctuation value by the actual water flow rate and dividing it by the standard water flow rate;

[0132] Adjust the pump speed according to the positive and negative and size of the circulating water flow rate influence coefficient. For example, if the circulating water flow rate influence coefficient is greater than zero and the value is large, it means that the pressure and flow rate work together to increase the system load, and the pump speed needs to be increased to maintain a stable flow rate; if the circulating water flow rate influence coefficient is less than zero, reduce the pump speed.

[0133] Set the initial pump speed to 1500rpm.

[0134] The pressure data corresponding to time point t1 is 1250pa, and the actual flow rate is 7.5m / s.

[0135] The pressure data corresponding to time point t2 is 1320pa, and the actual flow rate is 8.2m / s.

[0136] The pressure data corresponding to time point t3 is 1180pa, and the actual flow rate is 8.8m / s.

[0137] The pressure data corresponding to time point t4 is 1450pa, and the actual flow rate is 7.2m / s.

[0138] Set the base pressure to 1200Pa, at time point t1, the pressure difference is,

[0139] ,

[0140] The influence coefficient of circulating water flow rate is,

[0141] ,

[0142] If the pump speed adjustment coefficient is set to 0.05, the pump speed will increase to,

[0143] ;

[0144] At time point t2, the pressure difference is,

[0145] ,

[0146] The influence coefficient of circulating water flow rate is,

[0147] ,

[0148] The pump speed increases to,

[0149] , ...

[0150] At time point t4, the pressure difference is,

[0151] ,

[0152] The influence coefficient of circulating water flow rate is,

[0153] ,

[0154] The pump speed increases to,

[0155] .

[0156] Control flow rate fluctuations within an extremely small range to meet the needs of high-precision fluid dynamics experiments; integrate pressure data and flow rate differences to avoid the limitations of single parameter adjustment; set an upper flow rate threshold to prevent equipment damage and experimental accidents; optimize the initial pump speed adjustment path to reduce energy consumption and extend equipment life.

[0157] Specifically, the displacement monitoring mechanism monitors the actual displacement angle of the end point of the arresting plate at a preset time interval, and the data analysis module calculates the actual displacement rate based on the actual displacement angle difference and time interval of adjacent cycles.

[0158] Specifically, the data analysis module compares the actual displacement rate with the standard displacement rate interval, and determines whether to perform feedback adjustment on the pump speed based on the displacement rate comparison result.

[0159] Specifically, the control module adjusts the pump speed according to the displacement rate comparison result.

[0160] If the actual displacement rate is less than the minimum value of the standard displacement rate interval, the pump speed is increased according to the difference between the actual displacement rate and the minimum value of the standard displacement rate interval;

[0161] When the actual displacement rate is within the standard displacement rate range, the original pump speed is maintained;

[0162] In the case where the actual displacement rate is greater than the maximum value of the standard displacement rate interval, the pump speed is reduced according to the difference between the maximum value of the standard displacement rate interval and the actual displacement rate.

[0163] Set the monitoring time interval to 0.1s, the standard displacement rate range to [6.8, 7.5] degrees / second,

[0164] The actual displacement rate is determined by dividing the actual displacement angle difference by the time interval.

[0165] At time point t11, the actual displacement angle detected is 2.35 degrees;

[0166] At time point t12, the actual displacement angle detected is 3.12 degrees;

[0167] At time point t13, the actual displacement angle detected is 3.85 degrees;

[0168] At time point t14, the actual displacement angle detected is 4.53 degrees;

[0169] At time point t15, the actual displacement angle detected is 5.20 degrees;

[0170] During the time period t11-t12, the actual displacement rate is,

[0171] ;

[0172] During the time period t12-t13, the actual displacement rate is,

[0173] ;

[0174] During the time period t13-t14, the actual displacement rate is,

[0175] ;

[0176] During the time period t14-t15, the actual displacement rate is,

[0177] ;

[0178] During the time period t12-t13 and the time period t13-t14, the original pump speed is maintained;

[0179] During the time period t11-t12, the increased pump speed is determined based on the initial pump speed and the product of 1 plus the difference between the actual displacement rate and the minimum value of the standard displacement rate interval divided by the minimum value of the standard displacement rate interval.

[0180] ;

[0181] During the time period t14-t15, the reduced pump speed is determined based on the product of the initial pump speed and the difference between the actual displacement speed and the maximum value of the standard displacement speed interval, divided by the maximum value of the standard displacement speed interval.

[0182] .

[0183] By combining the Bernoulli equation with real-time data to construct the influence coefficient, the theoretical basis is retained while adapting to the nonlinear characteristics of the system. Pressure fluctuations and flow rate deviations are also taken into account to avoid the limitations of single-parameter control. The adjustment coefficient can be optimized online based on the equipment characteristics and operating conditions, achieving flexibility in the control system and enabling a shock-free, non-mutated, continuous and smooth dynamic response during parameter adjustment or external disturbance response. For cases where the actual displacement rate is less than the minimum value of the standard displacement rate interval, increasing the initial pump speed based on the difference between the actual displacement rate and the minimum value of the standard displacement rate interval can avoid reducing the efficiency of the high-speed water tunnel experiment due to too slow a circulating water flow rate. For cases where the actual displacement rate is greater than the maximum value of the standard displacement rate interval, reducing the initial pump speed based on the difference between the maximum value of the standard displacement rate interval and the actual displacement rate can avoid the formation of turbulence due to excessively fast circulating water flow rates, which would reduce the efficiency of the high-speed water tunnel experiment.

[0184] Thus far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art may make equivalent changes or substitutions to the relevant technical features, and the technical solutions after such changes or substitutions will fall within the scope of protection of the present invention.

Claims

1. A high-speed experimental water tunnel, characterized in that: include, Gas-water separation mechanism, used to separate gas from circulating water; An experimental device, which is connected to the gas-water separation mechanism and is provided with a contraction section capable of accelerating the flow rate of circulating water; a deceleration mechanism, which is arranged in the gas-water separation mechanism and is used to adjust the flow rate of the circulating water, comprising a baffle and a combined support rod, wherein the baffle is used to slow down the flow rate of the circulating water, and the combined support rod is used to support the baffle and can be extended and retracted according to the flow rate of the circulating water; a displacement monitoring mechanism, which is provided at the end point of the arresting plate and is used to detect the actual displacement angle of the end point of the arresting plate; A data acquisition module, used to collect pressure data and water flow velocity data in the experimental device; a data analysis module, connected to the gas-water separation mechanism, the experimental device, the displacement monitoring mechanism, and the data acquisition module, respectively, for determining whether the initial pumping speed of the pump body in the first water delivery pipe needs to be adjusted to obtain a target pumping speed based on the pressure data and the water flow rate data; a control module, connected to the data analysis module, configured to determine an actual displacement rate based on the actual displacement angle and a detection period of the displacement monitoring mechanism, compare the actual displacement rate with a standard displacement rate interval to obtain a displacement rate comparison result, and determine whether to perform feedback adjustment on the target pump speed based on the displacement rate comparison result; The pressure data is the air pressure in the experimental device; the water flow rate data is the circulating water flow rate after acceleration.

2. The high-speed experimental water tunnel according to claim 1, characterized in that: The gas-water separation mechanism comprises: The tank body is provided with an upper cutout and a lower cutout, wherein the upper cutout is connected to the first air pressure device, the lower cutout is connected to the lower water tank, and the lower water tank is connected to the experimental device through a second elbow; a partition disposed inside the tank body and connected to the inner wall of the tank body to form a closed space with an open upper end; Wherein, an inlet grille plate is provided at the opening of the partition, and a deceleration mechanism is provided inside the inlet grille plate.

3. The high-speed experimental water tunnel according to claim 2, characterized in that: The experimental device includes: A partitioned water tank is provided in the experimental device and is provided with a partition plate, wherein the partition plate is provided with a cutout for circulating water in the partitioned water tank; a venturi tube, which is arranged on the upper part of the partitioned water tank; The second air pressure device is arranged on the upper part of the partitioned water tank and is used to adjust the air pressure in the upper layer of the partitioned water tank.

4. The high-speed experimental water tunnel according to claim 3, characterized in that: The data acquisition module includes: a first data acquisition unit, configured to acquire a pressure value of the front section of the contraction section; a second data acquisition unit, configured to acquire a pressure value of the rear section of the contraction section; The detection unit detects whether the pressure value at the cross section of the rectifier tube meets the standard according to the front section pressure; and detects whether the pressure value at the throat section meets the standard according to the rear section pressure.

5. The high-speed experimental water tunnel according to claim 4, characterized in that: The data analysis module is used to determine the actual circulating water flow rate at the throat according to the pressure data of the front section pressure value and the rear section pressure value and the comprehensive influence coefficient; The comprehensive influence coefficient is determined according to the fluid density, the cross-sectional area at the rectifier tube cross section, and the cross-sectional area at the throat cross section.

6. The high-speed experimental water tunnel according to claim 5, characterized in that: The data analysis module is used to compare the actual circulating water flow rate with the standard circulating water flow rate to obtain a circulating water flow rate comparison result, and determine whether to adjust the initial pump speed according to the circulating water flow rate comparison result; The standard circulating water flow rate is determined according to the fluid dynamics parameters of the object to be detected in the high-speed experimental water tunnel.

7. The high-speed experimental water tunnel according to claim 6, characterized in that: The data analysis module is used to determine the circulating water flow rate influence coefficient according to the pressure data and the water flow rate data, and adjust the initial pump speed according to the circulating water flow rate influence coefficient.

8. The high-speed experimental water tunnel according to claim 7, characterized in that: The displacement monitoring mechanism monitors the actual displacement angle of the end point of the barrier plate at a preset time interval, and the data analysis module calculates the actual displacement rate based on the actual displacement angle difference and time interval of adjacent cycles.

9. The high-speed experimental water tunnel according to claim 8, characterized in that: The control module compares the actual displacement rate with the standard displacement rate interval to obtain a displacement rate comparison result, and determines whether to perform feedback adjustment on the target pump speed according to the displacement rate comparison result.

10. The high-speed experimental water tunnel according to claim 9, characterized in that: The control module is used to perform feedback adjustment on the target pump speed according to the displacement rate comparison result, or to keep the target pump speed unchanged.

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