Contact sensor mounting and adjusting device for water tunnel experiment

Abstract

The invention relates to a contact sensor mounting and adjusting device for a water tunnel experiment, which comprises a water tunnel cover plate and a slide rail cover plate connected above the water tunnel cover plate, the water tunnel cover plate is mounted and covered above a water tunnel, a movable adjusting part is mounted on the slide rail cover plate, and the tail end of the movable adjusting part is connected with a contact sensor. The device is used for adjusting the horizontal movement and the vertical movement of the contact type sensor. Compared with the prior art, the water tunnel sealing performance is guaranteed, meanwhile, fixing and moving adjustment of the contact type sensor can be simply, conveniently and reliably achieved, the contact type sensor can continuously move in the horizontal direction and the vertical direction in the experiment process, the experiment does not need to be paused, and the stability of experiment conditions and the repeatability of the experiment are guaranteed.

Description

Technical Field

[0001] The invention relates to the technical field of fluid mechanics experimental measurement, in particular to a contact sensor installation and adjustment device for water tunnel experiments. Background Art

[0002] In fluid mechanics research, water tunnel experiments are an important means to simulate the motion state of underwater objects, study the flow field characteristics and hydrodynamic performance around them, and provide important data support for the design and optimization of underwater vehicles such as ships, submarines, and underwater robots.

[0003] In order to obtain flow field measurement results, researchers have developed different flow measurement technologies. Among them, non-contact measurement technology (such as particle image velocimetry technology, laser Doppler velocimetry technology, etc.) can realize flow field measurement without interference. However, this type of technology is expensive and complex to operate, and it is impossible to obtain flow field information in special test scenarios (such as dense bubble flow and other flow fields with optical obscuration). Therefore, it is necessary to develop contact measurement technology to realize direct measurement of flow field physical quantities.

[0004] For probes and probe-type contact sensors that extend into the flow field, they generally need to be installed in a water tunnel, and the physical quantities of the local fluid are obtained through the physical effects generated by the fluid passing through the sensing element. However, there are many difficulties in installing and moving this type of sensor: First, during the water tunnel experiment, it is necessary to maintain the tightness of the water tunnel while ensuring good contact between the sensor and the flow field, which places high demands on installation accuracy and process; second, in order to obtain flow field data at different positions, it is usually necessary to move the sensor, and the design of the underwater moving mechanism needs to meet the positioning accuracy requirements of the sensor; in addition, the installation of the contact sensor will change the local flow boundary, thereby affecting the flow field characteristics and causing distortion of the measurement results.

[0005] Existing contact sensor mounting devices can only move the sensor in the vertical direction, and most of them are designed as disassembly solutions. That is, after completing a measurement position, the experiment needs to be paused, the device needs to be disassembled, and then reinstalled to the next measurement position, which makes the actual operation more complicated. At the same time, there is a chance that the sensitive end of the sensor will be damaged during operation. Summary of the Invention

[0006] The purpose of the present invention is to overcome the defects of the above-mentioned prior art and provide a contact sensor installation and adjustment device for water tunnel experiments, which can easily and reliably realize the fixation and movement adjustment of the contact sensor while ensuring the airtightness of the water tunnel.

[0007] The objectives of the present invention can be achieved through the following technical solutions: a contact sensor installation and adjustment device for water tunnel experiments, comprising a water tunnel cover plate and a slide rail cover plate connected above it, the water tunnel cover plate being installed to cover above the water tunnel, the slide rail cover plate being provided with a movable adjustment portion, the end of the movable adjustment portion being connected to the contact sensor for adjusting the horizontal and vertical movement of the contact sensor.

[0008] Furthermore, a slide rail is installed on the slide rail cover, and the slide rail is connected to the movable adjustment part.

[0009] Furthermore, the movement adjustment portion includes a horizontal adjustment unit and a vertical adjustment unit.

[0010] Furthermore, the horizontal adjustment unit includes a movable plate, which is connected to the slide rail through a slider, and a support tube is connected to the top of the movable plate. A ring is provided on the outside of the support tube, and the ring is rotatably connected to the horizontal screw rod. A horizontal handwheel is provided at the end of the horizontal screw rod, and the horizontal handwheel is rotated to drive the horizontal screw rod and the ring to move synchronously in the horizontal direction.

[0011] Furthermore, a horizontal nut is threadedly connected to the horizontal screw rod, and the horizontal nut is fixedly mounted on the slide rail cover.

[0012] Furthermore, the vertical adjustment unit includes a vertical handwheel, which is threadably connected to the vertical screw rod. The vertical handwheel and the top of the support tube can rotate freely, and the vertical screw rod can be driven to move synchronously in the vertical direction by rotating the vertical handwheel.

[0013] Furthermore, a sleeve is connected to the bottom of the movable plate through a movable thin plate, and the bottom end of the sleeve is sleeved on a transition elbow, which is connected to the bottom end of the vertical screw rod. When the vertical screw rod moves in the vertical direction, the transition elbow moves synchronously in the vertical direction.

[0014] Furthermore, the adapter elbow is connected to the contact sensor via a sensor connector, and the size and shape of the sensor connector are consistent with the outer shape of the contact sensor.

[0015] Furthermore, the adapter elbow and the vertical screw rod are both hollow structures, and the signal line of the contact sensor is led out through the adapter elbow and the vertical screw rod and connected to the equipment outside the water tunnel.

[0016] Furthermore, a sealing ring is arranged on the lower surface of the movable plate, and the lower surface of the movable plate is tightly fitted with the water hole cover.

[0017] Compared with the prior art, the present invention has the following advantages:

[0018] The present invention designs a water tunnel cover plate and a slide rail cover plate connected thereto. The water tunnel cover plate is installed over the water tunnel to ensure the tunnel's tightness. A movable adjustment portion is installed on the slide rail cover plate. The distal end of the movable adjustment portion is connected to a contact sensor, which can be used to adjust the contact sensor's horizontal and vertical movement. This ensures the water tunnel's tightness while enabling simple and reliable fixation and movement of the contact sensor. During an experiment, the contact sensor can be moved to its measurement position without pausing the experiment or disassembling and reinstalling it, significantly reducing the possibility of damage to the sensor's sensitive end during operation.

[0019] In the present invention, the movable adjustment part is designed to include a horizontal adjustment unit and a vertical adjustment unit, wherein the horizontal adjustment unit includes a movable plate, which is connected to the slide rail on the slide rail cover through a slider, and a support tube is connected to the upper part of the movable plate. A collar is provided on the outer part of the support tube, and the collar is rotatably connected to the horizontal screw rod. A horizontal hand wheel is provided at the end of the horizontal screw rod, thereby rotating the horizontal hand wheel to drive the horizontal screw rod and the collar to move synchronously in the horizontal direction;

[0020] The vertical adjustment unit includes a vertical handwheel, which is threadably connected to the vertical screw rod. The vertical handwheel and the top of the support tube rotate freely. The vertical screw rod is driven to move synchronously in the vertical direction by rotating the vertical handwheel. A sleeve is connected to the bottom of the movable plate through a movable thin plate. The bottom end of the sleeve is sleeved on the adapter elbow. The adapter elbow is connected to the bottom end of the vertical screw rod. When the vertical screw rod moves in the vertical direction, the adapter elbow is also driven to move synchronously in the vertical direction.

[0021] In this way, the contact sensor can be conveniently and reliably moved continuously in the horizontal and vertical directions, thereby realizing fine measurement of the sensor in a two-dimensional measurement plane.

[0022] The present invention connects and arranges a movable thin plate below the movable plate, and the movable thin plate can cover the cavity on the lower surface of the water tunnel cover plate. The cavity is the horizontal moving stroke of the movable plate, thereby reducing the impact on the flow inside the water tunnel.

[0023] In the present invention, the adapter elbow is connected to the contact sensor through a sensor connector, wherein the size and shape of the sensor connector are consistent with the appearance of the contact sensor, and can realize the fixation and connection of probes or probes of different shapes, thereby meeting the measurement requirements of various contact sensors.

[0024] The present invention arranges a sealing ring on the lower surface of the movable plate, and the lower surface of the movable plate is tightly fitted with the water hole cover plate, which can fully ensure the airtightness of the water hole during the experiment. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1It is a front view of the device of the present invention;

[0026] Figure 2 A top view of the device of the present invention;

[0027] Figure 3 is a bottom view of the device of the present invention;

[0028] Figure 4 It is a front view of the internal structure of the device of the present invention;

[0029] Figure 5 This is a schematic diagram of the installation effect of the device of Example 1;

[0030] Figure 6 This is a schematic diagram of the installation effect of the device of Example 2;

[0031] Explanation of the markings in the figure: 1. Water hole cover, 2. Slide rail cover, 3. Vertical screw, 4. Vertical handwheel, 5. Support tube, 6. Ring, 7. Horizontal screw, 8. Horizontal nut, 9. Horizontal handwheel, 10. Moving plate, 11. Sleeve, 12. Adapter elbow, 13. Sensor connector, 14. Moving plate, 15. Slide rail, 16. Slider. DETAILED DESCRIPTION

[0032] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0033] like Figures 1 to 4 As shown, Figure 1 This is the main view of the device, that is, the figure shows the horizontal and vertical directions (the common water tunnel uses a horizontal test section, and the flow is in the horizontal direction, from left to right in the figure). Figure 2 and Figure 3 They are top view and bottom view of the device respectively. Figure 4 This is the main view of the internal structure after removing some components from obstruction.

[0034] This proposal proposes a contact sensor installation and adjustment device for water tunnel experiments. The device's foundation consists of a water tunnel cover plate 1 and a slide rail cover plate 2, upon which all other components are mounted, directly or indirectly. The water tunnel cover plate 1 forms one side wall (usually the upper wall) of the water tunnel. Its dimensions must be designed based on the dimensions of the experimental water tunnel, ensuring that the cover plate 1 can be installed and maintains a tight seal. The slide rail cover plate 2 is connected to the water tunnel cover plate 1 via bolts.

[0035] Moving plate 14 (such as Figure 4(as shown) are the key components of this device. The support tube 5, sleeve 11 and movable thin plate 10 are directly bolted to the movable plate 14, while the vertical screw 3, vertical handwheel 4, adapter elbow 12 and sensor connector 13 are indirectly connected to the movable plate 14. The above components can all achieve synchronous horizontal movement with the movable plate 14. The movable plate 14 is installed on two slide rails 15 through four sliders 16 connected to it, so as to achieve horizontal movement along the slide rails 15. The slide rails 15 are connected to the slide rail cover 2 by bolts. A circle of sealing rings is arranged on the lower surface of the movable plate 14, which fits tightly with the water hole cover 1 to ensure the airtightness of the water hole during the experiment.

[0036] In this solution, the sensor connector 13 is a component that directly connects to the contact sensor. Its size and shape are specifically designed to suit the specific sensor's shape to ensure secure and sealed contact. The signal line at the sensor's tail end is also enclosed in the sensor connector 13 and extends through an adapter elbow 12 into the hollow vertical screw 3. From the top of the vertical screw 3, it extends to a device that connects to a signal amplifier or data acquisition card outside the water tunnel.

[0037] The vertical movement of the sensor is achieved by the vertical screw 3, vertical handwheel 4, and support tube 5. The bottom of the support tube 5 is bolted to the movable plate 14, and the top of the support tube 5 rotates freely between the vertical handwheel 4. The vertical screw 3 and the vertical handwheel 4 are threaded together. Rotating the vertical handwheel 4 causes the vertical screw 3 to move up and down, thereby driving the adapter elbow 12 and the sensor connector 13 to move vertically. The top of the sleeve 11 is mounted on the movable plate 14, and the bottom of the sleeve 11 is hollow and fits over the adapter elbow 12, allowing the adapter elbow 12 to move freely up and down within it.

[0038] The horizontal movement of the sensor is achieved by the collar 6, horizontal screw 7, horizontal nut 8, and horizontal handwheel 9. The collar 6 rotates freely with the left end of the horizontal screw 7, which is threaded into the horizontal nut 8. The horizontal handwheel 9 is fixed to the right end of the horizontal screw 7. Rotating the horizontal handwheel 9 allows the horizontal screw 7 and collar 6 to move synchronously left and right, thereby driving the movable plate 14 and its connected components to move horizontally.

[0039] The function of the movable plate 10 is to cover the cavity on the lower surface of the water tunnel cover 1 (this cavity is the horizontal travel of the movable plate 14), thereby reducing the impact on the flow inside the water tunnel. Because this thin plate is installed inside the water tunnel, its structural stability must be ensured under the impact of high-speed water flow. To prevent its front end from tilting, which would interfere with local flow characteristics and cause safety hazards, in practical applications, it should be made of high-rigidity metal materials (such as stainless steel).

[0040] After the above device is installed, the contact sensor can be moved horizontally and vertically in the water tunnel. The specific method is as follows:

[0041] a. Install the contact sensor inside the sensor connector 13. The specific installation method (such as sealant fixation or threaded installation) is determined by the shape of the sensor and sensor connector 13. Then install the sensor connector 13 to the adapter elbow 12. The sensor signal line is led out of the water tunnel through the adapter elbow 12 and the vertical screw 3. Connect to the sensor signal acquisition system outside the water tunnel.

[0042] b. Move the sensor's sensitive end to the initial measurement position by rotating the horizontal handwheel 9 and the vertical handwheel 4 to start the experiment;

[0043] c. Rotate the vertical hand wheel 4 to adjust the vertical position of the sensor to achieve measurement of multiple measuring points at a certain flow direction position;

[0044] d. Rotate the horizontal hand wheel 9 to adjust the flow direction position of the sensor and perform measurement at the next flow direction position;

[0045] e. The experiment ends when all predetermined measurement points are measured.

[0046] During the experiment, the sensor can move both horizontally and vertically, but the degrees of freedom of movement of each component in the device vary. Specifically, the components that cannot move include: the water hole cover plate 1, the slide rail cover plate 2, the horizontal nut 8, and the slide rail 15. The components that can only move horizontally include: the vertical handwheel 4, the support tube 5, the collar 6, the horizontal screw 7, the horizontal handwheel 9, the movable plate 10, the sleeve 11, the movable plate 14, and the slider 16. The components that can move both horizontally and vertically include: the vertical screw 3, the adapter elbow 12, and the sensor connector 13.

[0047] Example 1

[0048] like Figure 5 As shown, this embodiment utilizes the aforementioned device proposed in this solution to measure the internal vapor fraction of sheet cavitation using a fiber optic probe. The experimental setup consists of a cavitation water tunnel and a device from this solution that matches the dimensions of the water tunnel test section. The experimental model is a NACA0012 straight hydrofoil with a certain angle of attack. The experimental subject is the cavitation flow generated by the hydrofoil's suction surface. The experimental equipment consists of a fiber optic probe and its signal acquisition system. The specific measurement process is as follows:

[0049] Install the fiber optic probe into a sensor connector that matches its shape. Apply sealant to ensure a watertight structure and secure the connector with bolts. Install the tail of the sensor connector onto the adapter elbow. Route the signal cable from the fiber optic probe out of the water tunnel through the adapter elbow and vertical screw. Connect the fiber optic probe to the signal acquisition system outside the water tunnel. Apply sealant to the top of the vertical screw to prevent air from being drawn into the water tunnel under negative pressure conditions.

[0050] A NACA0012 straight hydrofoil with a chord length of 100 mm and a span of 225 mm was installed in the center of the cavitation water tunnel test section at an angle of attack of 6°, with the upper surface of the hydrofoil serving as the suction side. The cavitation number was approximately 1.3 when the incoming flow velocity in the cavitating water tunnel was set at 7 m / s and a static pressure of 33,620 Pa (15.6°C). The saturated vapor pressure was approximately 1,770 Pa (1770 Pa) and the atmospheric pressure was 100.2 kPa.

[0051] After the flow stabilized, the horizontal and vertical handwheels of the proposed device were used to move the tip of the fiber optic probe to a position 10 mm downstream of the hydrofoil's leading edge and 1 mm above the hydrofoil surface, serving as the first measurement point in this embodiment. At each measurement point, the fiber optic probe collected an optical signal for 60 seconds. The photoelectric conversion module then generated an electrical signal that distinguished the gas-liquid phases. Signal processing revealed the single-point vapor fraction and microbubble diameter distribution within the cavitation.

[0052] Use the vertical handwheel to move the fiber optic probe upward 0.5mm to the next measuring point for signal acquisition. Continue measuring point by point until the vapor content is less than 0.1%.

[0053] The fiber optic probe was moved 5 mm downstream using the horizontal handwheel to the next measurement line. The vertical handwheel was then used to move the fiber optic probe 1 mm above the hydrofoil surface to begin point-by-point measurement along that measurement line. This process continued until the probe reached a point 50 mm downstream of the hydrofoil's leading edge.

[0054] With the help of this device, the optical fiber probe inside the water tunnel can be finely adjusted in both the horizontal and vertical directions. The measurement results can be used to obtain the two-dimensional distribution of the vapor content inside the cavitation sheet and the evolution law of the cavitation micro-bubble bubble diameter distribution.

[0055] Example 2

[0056] like Figure 6 As shown, this embodiment utilizes the present invention's device to measure cloud cavitation pressure pulsations using a pressure probe. The experimental setup consists of a cavitation water tunnel and the present invention's device, which matches the dimensions of the water tunnel's test section. The experimental model is a three-dimensional twisted hydrofoil with a NACA16012t airfoil cross-section. The experimental subject is the cavitation flow generated by the hydrofoil's suction surface. The experimental equipment includes a high-speed camera, a pressure probe, and its signal acquisition system. The specific measurement process is as follows:

[0057] Install the pressure probe into a sensor connector that matches its shape. Fasten the base of the pressure probe to the connector head with threads. Install the tail of the sensor connector onto the adapter elbow. Lead the signal cable from the pressure probe through the adapter elbow and vertical screw out of the water tunnel and connect to the signal acquisition system outside the water tunnel. Apply sealant to the top of the vertical screw to prevent air from being drawn into the water tunnel under negative pressure conditions.

[0058] A NACA16012t three-dimensional twisted hydrofoil with a chord length of 100 mm and a span of 225 mm was installed in the center of the cavitation water tunnel test section. The angle of attack of the hydrofoil's symmetry plane was 11 degrees. The cavitation number was approximately 1.5 at an inflow velocity of 7 m / s and a static pressure of 38,850 Pa in the cavitating water tunnel, at a water temperature of 18°C ​​(saturated vapor pressure of approximately 2,100 Pa) and an atmospheric pressure of 101.2 kPa.

[0059] After the flow stabilizes, a high-speed camera is used to capture cavitation images. The area where cloud cavitation periodically detaches is found in the image. The horizontal and vertical hand wheels of the device of this solution are used to adjust the horizontal and vertical positions of the pressure probe so that the sensing element at the probe head is located inside the detached cloud cavitation, such as Figure 6 The measurement position is fixed, and the 5V switch signal of the high-speed camera is used as the trigger signal for pressure measurement to achieve synchronous acquisition of cavitation images and pressure pulsation signals.

[0060] With the help of this device, the pressure probe inside the water tunnel can be finely adjusted in both the horizontal and vertical directions. The sensing element at the head of the pressure probe can be precisely positioned at the location where the cloud cavitation falls off. Through the synchronous measurement of the high-speed camera and the pressure probe, the synchronous comparative analysis of the cavitation image and the pressure pulsation signal can be achieved.

[0061] In summary, the present invention realizes a contact sensor fixing and adjustment scheme with easy installation, flexible movement and low interference, which is of great significance for improving the efficiency and accuracy of water tunnel experiments.

Claims

1. A contact sensor installation and adjustment device for water tunnel experiments, characterized in that: The invention comprises a water hole cover plate (1) and a slide rail (15) cover plate (2) connected thereto. The water hole cover plate (1) is installed to cover the water hole. A movement adjustment portion is installed on the slide rail (15) cover plate (2). The end of the movement adjustment portion is connected to a contact sensor for adjusting the horizontal and vertical movement of the contact sensor.

2. The contact sensor installation and adjustment device for water tunnel experiment according to claim 1, characterized in that: The slide rail (15) cover plate (2) is provided with a slide rail (15), and the slide rail (15) is connected to the movable adjustment part.

3. The contact sensor installation and adjustment device for water tunnel experiment according to claim 2, characterized in that: The movement adjustment part includes a horizontal adjustment unit and a vertical adjustment unit.

4. The contact sensor installation and adjustment device for water tunnel experiment according to claim 3, characterized in that: The horizontal adjustment unit comprises a movable plate (14), the movable plate (14) being connected and installed with a slide rail (15) via a slider (16), a support tube (5) being connected above the movable plate (14), a collar (6) being provided on the outside of the support tube (5), the collar (6) being rotatably connected with a horizontal screw rod (7), a horizontal hand wheel (9) being provided at the end of the horizontal screw rod (7), and the horizontal hand wheel (9) being rotated to drive the horizontal screw rod (7) and the collar (6) to move synchronously in the horizontal direction.

5. The contact sensor installation and adjustment device for water tunnel experiment according to claim 4, characterized in that: The horizontal screw rod (7) is threadedly connected with a horizontal nut (8), and the horizontal nut (8) is fixedly mounted on the slide rail (15) cover plate (2).

6. The contact sensor installation and adjustment device for water tunnel experiment according to claim 4, characterized in that: The vertical adjustment unit comprises a vertical hand wheel (4), the vertical hand wheel (4) is threadedly connected to the vertical screw rod (3), the vertical hand wheel (4) is freely rotatable with the top of the support tube (5), and the vertical screw rod (3) is driven to move synchronously in the vertical direction by rotating the vertical hand wheel (4).

7. The contact sensor installation and adjustment device for water tunnel experiment according to claim 6, characterized in that: A sleeve (11) is connected to the bottom of the movable plate (14) through a movable thin plate (10), and the bottom end of the sleeve (11) is sleeved on a transition elbow (12). The transition elbow (12) is connected to the bottom end of the vertical screw rod (3). When the vertical screw rod (3) moves in the vertical direction, the transition elbow (12) moves synchronously in the vertical direction.

8. The contact sensor installation and adjustment device for water tunnel experiment according to claim 7, characterized in that: The adapter elbow (12) is connected to the contact sensor via a sensor connector (13), and the size and shape of the sensor connector (13) are consistent with the outer shape of the contact sensor.

9. The contact sensor installation and adjustment device for water tunnel experiment according to claim 7, characterized in that: The adapter elbow (12) and the vertical screw rod (3) are both hollow structures, and the signal line of the contact sensor is led out through the adapter elbow (12) and the vertical screw rod (3) and connected to the equipment outside the water tunnel.

10. The contact sensor installation and adjustment device for water tunnel experiment according to claim 4, characterized in that: A sealing ring is arranged on the lower surface of the movable plate (14), and the lower surface of the movable plate (14) is tightly fitted to the water hole cover plate (1).

Images