External electric field type non-isothermal liquid bridge generator and liquid bridge measurement method

Abstract

The invention relates to the technical field of fluid physics experiment devices, in particular to an external electric field type non-isothermal liquid bridge generator and a liquid bridge measurement method, and the external electric field type non-isothermal liquid bridge generator comprises a liquid bridge generation device, an electric field device and a temperature control device; the upper disc assembly is in threaded connection with the upper bridge seat through a threaded shaft; a sliding shaft of the lower disc assembly is inserted into the lower bridge seat; the upper bridge seat and the lower bridge seat are fixedly connected to the upper and lower ends of the inner support respectively. The left and right ends of a fixed shaft in the electric field device are respectively mounted on a fixed shaft bracket connecting hole and an inner bracket connecting hole; the driving bearing and the driven bearing sleeve the left fixed shaft and the right fixed shaft; left and right ends of the electrode plates are inserted into the notches of the electrode plate supports. A heating piece in the temperature control device is installed in a heating groove of the upper plate assembly, and a refrigerating piece is installed in a refrigerating groove of the lower plate assembly. Compared with the prior art, the external electric field is applied to the liquid bridge, the electric field intensity and the electric field angle are adjusted according to experiment requirements, oscillation Marangoni convection in the liquid bridge is effectively inhibited, and the device has remarkable guiding significance in preparation of single crystals through a floating zone method.

Description

Technical Field

[0001] This invention relates to the field of experimental apparatus technology in fluid physics, specifically to an externally applied electric field type non-isothermal liquid bridge generator. Background Technology

[0002] The floating zone method is a common method for preparing semiconductor crystal materials. Its main principle is that a feed rod is pulled within a ring heater, causing the solid raw material near the heater to melt and form a molten zone. This molten zone then cools and crystallizes as it moves away from the heater. The quality of the grown crystal is affected by the periodic oscillating Marangoni convection within the molten zone, which can produce micron-sized impurity streaks, severely impacting the quality of the crystal. The liquid bridge method, based on the floating zone method for single crystal preparation, uses a physical experimental model with an upper plate simulating the ring heater and a lower plate simulating the feed rod for cooling. This model is used to study the transition of Marangoni convection within the molten zone from steady-state flow to oscillating flow under laboratory conditions, and its impact on the crystal surface shape.

[0003] Currently, mature methods for suppressing Marangoni convection, which causes periodic oscillations within the molten zone, include external vibration, external rotation, surface coating, and shear gas flow. Experimental and simulation studies have shown that an external electric field can effectively suppress oscillating Marangoni convection within the molten zone, improving the quality of crystal preparation. However, no external electric field-based liquid bridge generation technology has yet been developed, thus necessitating the development of an external electric field-based non-isothermal liquid bridge generation technology. Summary of the Invention

[0004] The technical solution adopted by the present invention to solve the above-mentioned technical problems is: an external electric field type non-isothermal liquid bridge generator, including a liquid bridge generating device, an electric field device, and a temperature control device; the liquid bridge generating device includes an upper plate assembly, a lower plate assembly, and an inner support, wherein the upper end of the upper plate assembly is connected to the inner support, the upper plate assembly is provided with a heating groove, and the lower end of the upper plate assembly is provided with an upper plate; the lower end of the lower plate assembly is connected to the inner support, the lower plate assembly is provided with a cooling groove, and the upper end of the lower plate assembly is provided with a lower plate; the diameters of the lower plate and the upper plate are matched equally; the vertical center lines of the upper plate assembly and the lower plate assembly are located on the same vertical straight line; the side of the inner support is provided with an inner support connection hole for connecting to the electric field device; The electric field device includes two electrode plates, an electrode plate support, a driving bearing, a driven bearing, two fixed shafts on the left and right, and two fixed shaft supports on the left and right. The two fixed shafts are respectively fixed on the two fixed shaft supports and are fixedly connected to the inner support connecting holes on both sides of the inner support. The electrode plate support is arranged around the inner support, and its two sides are respectively connected to the driving bearing and the driven bearing arranged on the two fixed shafts. Electrode plates are respectively provided at both ends of the electrode plate support. The driving bearing is driven to rotate by a rotating gear installed on the rotating shaft of a rotary motor. The temperature control device includes a temperature controller, two relays, two transformers, a heating element, a cooling element, and two thermocouples. The heating element is installed in the heating slot of the upper plate assembly and is connected to a set of transformers and relays to form a heating circuit. The cooling element is installed in the cooling slot of the lower plate assembly and is connected to another set of transformers and relays to form a cooling circuit. The temperature controller is connected to the relays and thermocouples to form a control circuit. The two thermocouples are respectively attached to the upper plate and the lower plate.

[0005] As a further optimization of the aforementioned external electric field-type non-isothermal liquid bridge generator, the liquid bridge generating device further includes an upper bridge seat and a lower bridge seat, which are respectively fixedly connected to the upper and lower ends of the inner support. The upper end of the upper plate assembly is provided with a threaded shaft, which is threadedly connected to the threaded hole provided in the upper bridge seat. The lower end of the lower plate assembly is provided with a sliding shaft, which is inserted into the circular hole provided in the lower bridge seat and fixed by a fixing bolt provided on one side of the lower bridge seat.

[0006] As a further optimization of the above-mentioned external electric field type non-isothermal liquid bridge generator, the bottom of the fixed axis bracket is fixedly mounted on the base, the fixed axis bracket is provided with a fixed axis bracket connection hole, the left and right ends of the fixed axis are respectively installed on the fixed axis bracket connection hole and the inner bracket connection hole and fixed with nuts, and a motor slot for installing a rotary motor is provided on the base.

[0007] As a further optimization of the aforementioned external electric field type non-isothermal liquid bridge generator, the active bearing and the driven bearing are respectively mounted on the left and right fixed shafts. The active bearing includes an active stator, an active rotor, and an active roller, while the driven bearing includes a driven stator, a driven rotor, and a driven roller. The inner sides of the active stator and the driven stator are respectively provided with strip-shaped slots. The circumferential surfaces of the active rotor and the driven rotor are respectively provided with openings for inserting electrode plate supports. The sides of the active rotor and the driven rotor are respectively provided with threaded circular holes for installing bolts to fix the electrode plate supports. The outer side of the active rotor is provided with a bevel gear that meshes with a rotating gear. The rotating motor rotates and drives the active bearing and the driven bearing to rotate around the left and right fixed shafts through the rotating gear.

[0008] As a further optimization of the above-mentioned external electric field type non-isothermal liquid bridge generator, the electrode plate support includes four L-shaped support units. The long ends of the four L-shaped support units are respectively installed in the openings of the active bearing and the driven bearing, and are fixed by bolts in the threaded round holes on the side. The short ends of the four L-shaped support units are correspondingly positioned, and notches are opened on the short ends. The left and right ends of the electrode plate are inserted into the notches and fixed to the electrode plate support by bolts and nuts.

[0009] As a further optimization of the above-mentioned external electric field type non-isothermal liquid bridge generator, a synchronous transmission bracket is also included. The synchronous transmission bracket has a U-shaped structure. The two sides of the synchronous transmission bracket are respectively installed in the openings on the active bearing and the driven bearing, and are fixed by bolts in the threaded round holes on the side, so that the active bearing drives the driven bearing to rotate synchronously through the synchronous transmission bracket.

[0010] As a further optimization of the aforementioned external electric field-type non-isothermal liquid bridge generator, the fixed shaft includes a shaft body, a threaded head, a square clamp, a retaining ring, and retaining strips. The shaft body has a cylindrical structure, with square clamps and a threaded head extending outwards from both ends of the shaft body. The square clamps on both sides are respectively installed in square slots provided in the fixed shaft bracket connection hole and the inner bracket connection hole to fix and restrict the rotation of the fixed shaft. The upper part of the fixed shaft bracket connection hole is an open opening to facilitate the disassembly of the fixed shaft. A retaining ring is provided on the shaft body, and multiple retaining strips are provided on the inner side of the retaining ring. The retaining strips are inserted into the retaining grooves on the inner side of the active stator in the active bearing or the driven stator in the driven bearing to prevent the rotation of the active stator or the driven stator.

[0011] As a further optimization of the above-mentioned externally applied electric field type non-isothermal liquid bridge generator, the upper and lower plate components are made of aluminum nitride ceramic material.

[0012] As a further optimization of the above-mentioned externally applied electric field type non-isothermal liquid bridge generator, the upper bridge seat, lower bridge seat, inner support, and electrode plate support are made of polyethylene resin.

[0013] The method of liquid bridge measurement using an external electric field-type non-isothermal liquid bridge generator involves injecting experimental liquid between the upper and lower plates, allowing the liquid bridge to maintain its interface shape through surface tension. A temperature control device is activated to heat the upper plate of the liquid bridge at a constant temperature and cool the lower plate at a constant temperature, creating a temperature difference between the two plates. An electric field device is activated, controlling the electric field strength through a power supply connected to the electrode plates and controlling the electric field angle through a rotating motor to obtain the required electric field conditions. A high-speed camera is used to capture the dynamic deformation of the free surface of the liquid bridge, or a laser sheet light source is used to penetrate the liquid bridge along its central axis to illuminate the two-dimensional plane containing the laser light source. A high-speed camera then captures the tracer particles illuminated by the laser within this two-dimensional plane to obtain the flow state inside the liquid bridge.

[0014] Compared with the prior art, the beneficial effects of the present invention are: I. The present invention has a simple structure. Compared with the traditional liquid bridge generator, it can apply an external electric field to the liquid bridge and adjust the electric field strength and electric field angle according to experimental needs.

[0015] Second, the present invention uses an electric field device to suppress the Marangoni convection oscillation inside the liquid bridge. This is a non-direct contact method, which avoids overall damage to the liquid bridge structure compared with traditional methods such as vibration, rotation, and shearing airflow.

[0016] Third, the unique structural design of this invention allows for the high degree of disassembly of parts in the liquid bridge device and electric field device, facilitating the replacement of damaged parts during use and saving experimental costs.

[0017] Fourth, the temperature difference between the upper and lower plates of this invention can be precisely controlled according to experimental requirements, and can provide a wide range of temperature differences, including the critical temperature difference, which is convenient for studying the entire process of transition from steady flow to oscillating flow.

[0018] 5. The upper and lower plates of different diameters (the upper and lower plates have the same diameter) can be replaced, and the distance between the upper and lower plates can be adjusted to provide liquid bridges with different height-to-diameter ratios and volume ratios.

[0019] VI. Taking into account the influence of various factors on the crystal growth process, the data obtained by this method is more comprehensive, stable and reliable than that obtained by existing liquid bridge generators, which is of great significance for studying the crystal growth process in the floating zone. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of the external electric field type non-isothermal liquid bridge generator of the present invention; Figure 2 This is a schematic diagram of the structure of the upper plate assembly of the present invention; Figure 3 This is a schematic diagram of the lower plate assembly of the present invention; Figure 4 This is a schematic diagram of the front structure of the active bearing of the present invention; Figure 5 This is a schematic diagram of the back structure of the active bearing of the present invention; Figure 6 This is a schematic diagram of the front structure of the driven bearing of the present invention; Figure 7 This is a schematic diagram of the back structure of the driven bearing of the present invention; Figure 8 This is a schematic diagram of the fixed-axis structure of the present invention; Figure 9 This is a circuit diagram of the temperature control device of the present invention; Figure 10 This is a schematic diagram of the experimental setup for measuring the internal flow field of the liquid bridge according to the present invention. Figure 11 This is a schematic diagram of the experimental apparatus for measuring the free surface shape of a liquid bridge according to the present invention.

[0021] The components include: 1. Upper plate assembly, 1-1. Upper plate, 1-2. Heating tank, 1-3. Threaded shaft; 2. Lower plate assembly, 2-1. Lower plate, 2-2. Cooling tank, 2-3. Sliding shaft; 3. Upper bridge seat; 4. Lower bridge seat; 5. Fixing bolt; 6. Inner support; 7. Electrode plate; 8. Electrode plate support; 9. Driven bearing, 9-1. Driven stator, 9-2. Driven rotor, 9-3. Driven roller; 10. Driven bearing, 10-1. Driven stator, 10-2. Driven rotor, 10-3. Driven roller; 11. Synchronous transmission support; 12. Fixed shaft, 12 -1. Shaft; 12-2. Threaded head; 12-3. Square clasp; 12-4. Snap ring; 12-5. Clamping strip; 13. Fixed shaft bracket; 14. Rotary gear; 15. Rotary motor; 16. Motor slot 16; 17. Base; 18. Fixed shaft bracket connecting hole; 19. Inner bracket connecting hole; 20. Heating element; 21. Cooling element; 22. Transformer; 23. Relay; 24. Temperature controller; 25. Thermocouple; 26. High-speed camera; 27. Laser light source; 28. Image processing system; 29. ​​Liquid bridge; 30. Backlight; 31. Diffuser. Detailed Implementation

[0022] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0023] Example 1 See Figure 1 An external electric field-type non-isothermal liquid bridge generator includes a liquid bridge generating device, an electric field device, and a temperature control device; the liquid bridge generating device includes an upper plate assembly 1, a lower plate assembly 2, an upper bridge seat 3, a lower bridge seat 4, fixing bolts 5, and an inner support 6; wherein, along the axial direction of the upper plate assembly 1, an upper plate 1-1, a heating tank 1-2, and a threaded shaft 1-3 (e.g., ...) are arranged sequentially. Figure 2 As shown); along the axial direction of the lower plate assembly 2, the lower plate 2-1, the cooling tank 2-2, and the sliding shaft 2-3 are arranged sequentially (as shown). Figure 3 As shown), the diameters of the lower plate 2-1 and the upper plate 1-1 are equal; the threaded shaft 1-3 of the upper plate assembly 1 is threadedly connected to the threaded hole of the upper bridge seat 3; the sliding shaft 2-3 of the lower plate assembly 2 is inserted into the circular hole of the lower bridge seat 4 and fixed by the fixing bolt 5 on one side of the lower bridge seat 4; the vertical center lines of the upper plate assembly 1, the lower plate assembly 2, the upper bridge seat 3 and the lower bridge seat 4 are located on the same vertical straight line; the upper bridge seat 3 and the lower bridge seat 4 are fixedly connected to the upper and lower ends of the inner support 6, respectively; the inner support 6 has an inner support connection hole 19 for connecting to the electric field device on its side.

[0024] See Figure 1The electric field device includes two upper and lower electrode plates 7, an electrode plate support 8, a driving bearing 9, a driven bearing 10, a synchronous transmission support 11, two left and right fixed shafts 12, two left and right fixed shaft supports 13, a rotating gear 14, a rotating motor 15, a motor slot 16, and a base 17. The bottoms of the fixed shaft supports 13 and the motor slot 16 are fixedly mounted on the base 17. The fixed shaft supports 13 are provided with fixed shaft support connection holes 18. The left and right ends of the fixed shafts 12 are respectively installed in the fixed shaft support connection holes 18 and the inner support connection holes 19 and are fixed with nuts. The rotating gear 14 is inserted into the rotating shaft of the rotating motor 15, and the rotating motor 15 is installed in the motor slot 16.

[0025] The temperature control device described herein has the following structure: Figure 9 As shown, the assembly includes a thermostat 24, two relays 23, two transformers 22, a heating element 20, a cooling element 21, and two thermocouples 25. The heating element 20 is installed in the heating slot 1-2 of the upper plate assembly 1 and connected to the transformer 22 and relay 23 to form a heating circuit. The cooling element 21 is installed in the cooling slot 2-2 of the lower plate assembly 2 and connected to the transformer 22 and relay 23 to form a cooling circuit. The thermostat 24 is connected to the relay 23 and thermocouples 25 to form a control circuit. The two thermocouples are respectively attached to the upper plate 1-1 and the lower plate 2-1.

[0026] Example 2 See Figures 4 to 7 In Embodiment Two, based on Embodiment One, the driving bearing 9 and the driven bearing 10 are further optimized. The driving bearing 9 and the driven bearing 10 are respectively mounted on the left and right fixed shafts 12. The driving bearing 9 includes a driving stator 9-1, a driving rotor 9-2, and a driving roller 9-3. The driven bearing 10 includes a driven stator 10-1, a driven rotor 10-2, and a driven roller 10-3. The inner sides of the driving stator 9-1 and the driven stator 10-1 are respectively provided with strip-shaped grooves. The driving rotor 9-2 and the driven rotor 10... -2 has openings on its circumferential surface for inserting electrode plate bracket 8 and synchronous transmission bracket 11. The sides of the active rotor 9-2 and driven rotor 10-2 are respectively provided with threaded circular holes for mounting bolts to fix electrode plate bracket 8 and synchronous transmission bracket 11. The outer side of the active rotor 9-2 is provided with a bevel gear that meshes with the rotating gear 14. The rotating motor 15 rotates and drives the active bearing 9 and driven bearing 10 through the rotating gear 14. The active bearing 9 drives the driven bearing 10 to rotate synchronously through the synchronous transmission bracket 11.

[0027] Example 3 See Figure 1In Example 3, the electrode plate support 8 is further optimized based on Example 1. The electrode plate support 8 includes four L-shaped support units. The long ends of the four L-shaped support units are respectively installed in the openings of the driving bearing 9 and the driven bearing 10, and are fixed by bolts in the threaded round holes on the side. The short ends of the four L-shaped support units are correspondingly positioned and have notches on the short ends. The left and right ends of the electrode plate 7 are inserted into the notches and fixed to the electrode plate support 8 by bolts and nuts.

[0028] Example 4 See Figure 1 In Example 4, based on Example 1, the synchronous transmission bracket 11 is further optimized. The synchronous transmission bracket 11 has a U-shaped structure. The two sides of the synchronous transmission bracket 11 are respectively installed in the openings of the active bearing 9 and the driven bearing 10, and are fixed by bolts in the threaded round holes on the side, so that the active bearing 9 drives the driven bearing 10 to rotate synchronously through the synchronous transmission bracket 11.

[0029] Example 5 See Figure 1 and Figure 8 Example 5 further optimizes the fixed shaft 12 based on Example 1. The fixed shaft 12 includes a shaft body 12-1, a threaded head 12-2, a square clamp head 12-3, a retaining ring 12-4, and a retaining strip 12-5. The shaft body 12-1 has a cylindrical structure. The square clamp head 12-3 and the threaded head 12-2 are arranged sequentially at the front and rear ends of the shaft body 12-1. The square clamp heads 12-3 on both sides are respectively installed in the fixed shaft bracket connecting hole 18 and the inner... The square slot in the bracket connection hole 19 is used to fix and restrict the rotation of the fixed shaft 12. The upper part of the fixed shaft bracket connection hole 18 is an open opening to facilitate the disassembly of the fixed shaft 12. A retaining ring 12-4 is provided on the shaft body 12-1. Multiple retaining strips 12-5 are provided on one side of the retaining ring 12-4. The retaining strips 12-5 are respectively inserted into the retaining slots inside the active stator 9-1 and the driven stator 10-1 to prevent the rotation of the active stator 9-1 and the driven stator 10-1.

[0030] Example 6 In Example 6, based on Example 1, the materials of the upper plate assembly 1 and the lower plate assembly 2 were further optimized. The upper plate assembly 1 and the lower plate assembly 2 are made of aluminum nitride ceramic material. The electrical insulation properties of aluminum nitride ceramic can prevent the upper plate assembly 1 and the lower plate assembly 2 from being affected by the electric field and thus interfering with the liquid bridge experiment. On the other hand, the high thermal conductivity of aluminum nitride ceramic can maintain the experimental temperature difference required between the upper and lower plates.

[0031] Example 7 Based on Example 1, Example 7 further optimizes the materials of the upper bridge seat 3, lower bridge seat 4, inner support 6, electrode plate support 8, and synchronous transmission support 11. The materials of the upper bridge seat 3, lower bridge seat 4, inner support 6, electrode plate support 8, and synchronous transmission support 11 are polyethylene resin materials to prevent interference with the internal temperature difference and electric field of the liquid bridge experiment.

[0032] The process of conducting a liquid bridge generation experiment using the liquid bridge generator of this invention is as follows: First, select upper plate 1-1 and lower plate 2-1 of the same diameter for the liquid bridge. Adjust the distance between upper plate 1-1 and lower plate 2-1 using fixing bolt 5 to obtain the required height-to-diameter ratio of the liquid bridge. Then, use a micro-syringe pump to accurately inject the experimental liquid between upper plate 1-1 and lower plate 2-1 to obtain the required liquid bridge volume ratio. The static liquid bridge maintains its interface shape through surface tension. Turn on the temperature control device and set the experimental temperature using temperature controller 24. Heat the upper plate 1-1 of the liquid bridge at a constant temperature and cool the lower plate 2-1 at a constant temperature to create a temperature difference between the two plates. Turn on the electric field device and control the electric field strength by connecting the power supply to the electrode plate 7. Control the electric field angle by rotating the motor 15 to obtain the required electric field conditions for the experiment. There are two specific measurement schemes: 1) Measuring the Marangoni convection inside the liquid bridge; such as Figure 10 As shown, the liquid bridge generator, high-speed camera 26, and laser sheet light source 27 are placed vertically, allowing the blade-thin laser sheet light source 27 to penetrate the liquid bridge 29 along its central axis and illuminate the two-dimensional plane containing the laser sheet light source 27. The tracer particles in this two-dimensional plane, illuminated by the laser, reflect the light, which is then captured by the high-speed camera 26, thus obtaining the flow state inside the liquid bridge 29; 2) Measuring the dynamic deformation of the free surface of the liquid bridge; such as Figure 11 As shown, the liquid bridge generator, high-speed camera 26, backlight 30 and diffuser 31 are on the same straight line, and the high-speed camera 26 captures the dynamic deformation of the free surface of the liquid bridge 29.

[0033] The external electric field-type non-isothermal liquid bridge generator of this invention can be used to study the effects of experimental variables such as electric field strength, electric field angle, temperature difference, and the height-to-diameter ratio and volume ratio of the liquid bridge on the internal flow and free surface shape of the liquid bridge. It can be implemented through the following five specific experimental schemes: Experiment 1: Under the condition that the electric field angle, the temperature difference between the upper and lower plates, the height-to-diameter ratio and the volume ratio of the liquid bridge are constant, different electric field intensities are varied to study the effect of electric field intensity on the internal flow and surface shape of the liquid bridge.

[0034] Experiment 2: Under the condition that the electric field strength, temperature difference between the upper and lower plates, and the height-to-diameter ratio and volume ratio of the liquid bridge are constant, different electric field angles are changed to study the influence of the electric field angle on the internal flow and surface shape of the liquid bridge.

[0035] Experiment 3: With constant electric field strength, electric field angle, liquid bridge height-to-diameter ratio, and volume ratio, different temperature differences between the upper and lower plates were varied to study the effects of the temperature difference between the upper and lower plates on the internal flow and surface shape of the liquid bridge.

[0036] Experiment 4: Under the condition that the electric field strength, electric field angle, temperature difference between the upper and lower plates, and liquid bridge volume ratio are constant, different liquid bridge height-to-diameter ratios are changed to study the influence of the liquid bridge height-to-diameter ratio on the internal flow and surface shape of the liquid bridge.

[0037] Experiment 5: With constant electric field strength, electric field angle, temperature difference between the upper and lower plates, and liquid bridge height-to-diameter ratio, different liquid bridge volume ratios were varied to study the effects of liquid bridge volume ratio on the internal flow and surface shape of the liquid bridge.

[0038] This invention features a simple structure and, compared to traditional liquid bridge generators, allows for the application of an external electric field to the liquid bridge. The electric field strength and angle can be adjusted according to experimental needs. This invention uses an electric field device to suppress Marangoni convection oscillations within the liquid bridge, employing a non-direct contact method that avoids overall damage to the liquid bridge structure compared to traditional methods such as vibration, rotation, and shearing airflow. The unique structural design allows for the high degree of disassembly of components in both the liquid bridge and electric field devices, facilitating the replacement of damaged parts and saving experimental costs. The temperature difference between the upper and lower plates can be precisely controlled according to experimental requirements and can provide a wide range of temperature differences, including the critical temperature difference, facilitating the study of the entire process from steady-state flow to oscillating flow. Different diameter upper and lower plates (with the same diameter) can be used, and the distance between the upper and lower plates can be adjusted to provide liquid bridges with different aspect ratios and volume ratios. Considering the influence of various factors on the crystal growth process, the data obtained from this invention is more comprehensive, stable, and reliable than that obtained from existing liquid bridge generators, which is of great significance for studying the crystal growth process in floating zones.

[0039] The preferred embodiments and examples of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments and examples. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the concept of the present invention.

Claims

1. An externally applied electric field type non-isothermal liquid bridge generator, characterized in that: The device includes a liquid bridge generating device, an electric field device, and a temperature control device. The liquid bridge generating device includes an upper plate assembly (1), a lower plate assembly (2), and an inner support (6). The upper end of the upper plate assembly (1) is connected to the inner support (6), and the upper plate assembly (1) is provided with a heating groove (1-2). The lower end of the upper plate assembly (1) is provided with an upper plate (1-1). The lower end of the lower plate assembly (2) is connected to the inner support (6), and the lower plate assembly (2) is provided with a cooling groove (2-2). The upper end of the lower plate assembly (2) is provided with a lower plate (2-1). The diameters of the lower plate (2-1) and the upper plate (1-1) are equal. The vertical center lines of the upper plate assembly (1) and the lower plate assembly (2) are located on the same vertical line. The inner support (6) has an inner support connection hole (19) on its side for connection with the electric field device. The electric field device includes two electrode plates (7), an electrode plate bracket (8), a driving bearing (9), a driven bearing (10), two left and right fixed shafts (12), and two left and right fixed shaft brackets (13); the two fixed shafts (12) are respectively fixed on the two fixed shaft brackets (13) and are fixedly connected to the inner bracket connection holes (19) on both sides of the inner bracket (6); the electrode plate bracket (8) is arranged around the inner bracket (6), and its two sides are respectively connected to the driving bearing (9) and the driven bearing (10) arranged on the two fixed shafts (12); the two ends of the electrode plate bracket (8) are respectively provided with electrode plates (7); the driving bearing (9) is driven to rotate by a rotating gear (14) installed on the rotating shaft of the rotary motor (15); The temperature control device includes a temperature controller (24), two relays (23), two transformers (22), a heating element (20), a cooling element (21), and two thermocouples (25). The heating element (20) is installed in the heating slot (1-2) of the upper plate assembly (1) and is connected to a set of transformers (22) and relays (23) to form a heating circuit. The cooling element (21) is installed in the cooling slot (2-2) of the lower plate assembly (2) and is connected to another set of transformers (22) and relays (23) to form a cooling circuit. The temperature controller (24) is connected to the relays (23) and thermocouples (25) to form a control circuit. The two thermocouples (25) are respectively attached to the upper plate (1-1) and the lower plate (2-1).

2. The externally applied electric field type non-isothermal liquid bridge generator as described in claim 1, characterized in that: The liquid bridge generating device further includes an upper bridge seat (3) and a lower bridge seat (4). The upper bridge seat (3) and the lower bridge seat (4) are respectively fixedly connected to the upper end and the lower end of the inner support (6). The upper end of the upper plate assembly (1) is provided with a threaded shaft (1-3), and the threaded shaft (1-3) is connected to the threaded hole provided in the upper bridge seat (3) by thread. The lower end of the lower plate assembly (2) is provided with a sliding shaft (2-3), which is inserted into the round hole provided in the lower bridge seat (4) and fixed by a fixing bolt (5) provided on one side of the lower bridge seat (4).

3. The externally applied electric field type non-isothermal liquid bridge generator as described in claim 1, characterized in that: The bottom of the fixed axis bracket (13) is fixedly mounted on the base (17). The fixed axis bracket (13) is provided with a fixed axis bracket connection hole (18). The left and right ends of the fixed axis (12) are respectively installed on the fixed axis bracket connection hole (18) and the inner bracket connection hole (19) and fixed with nuts. The base (17) is provided with a motor slot (16) for installing the rotary motor (15).

4. The externally applied electric field type non-isothermal liquid bridge generator as described in claim 1, characterized in that: The driving bearing (9) and driven bearing (10) are respectively sleeved on the left and right fixed shafts (12). The driving bearing (9) includes a driving stator (9-1), a driving rotor (9-2), and a driving roller (9-3). The driven bearing (10) includes a driven stator (10-1), a driven rotor (10-2), and a driven roller (10-3). The inner sides of the driving stator (9-1) and the driven stator (10-1) are respectively provided with strip-shaped slots. The driving rotor (9-2) and the driven rotor (10-3) are respectively provided with strip-shaped slots. -2) has openings on its circumferential surface for inserting electrode plate brackets (8). The active rotor (9-2) and the driven rotor (10-2) have threaded round holes on their sides for installing bolts to fix the electrode plate brackets (8). The outer side of the active rotor (9-2) is provided with a bevel gear that meshes with the rotating gear (14). The rotating motor (15) rotates and drives the active bearing (9) and the driven bearing (10) through the rotating gear (14) to rotate around the left and right fixed axes (12).

5. The externally applied electric field type non-isothermal liquid bridge generator as described in claim 4, characterized in that: The electrode plate bracket (8) includes four L-shaped bracket units. The long ends of the four L-shaped bracket units are respectively installed in the openings of the drive bearing (9) and the driven bearing (10) and fixed by bolts in the threaded round holes on the side. The short ends of the four L-shaped bracket units are in corresponding positions and have notches on the short ends. The left and right ends of the electrode plate (7) are inserted into the notches and fixed to the electrode plate bracket (8) by bolts and nuts.

6. The externally applied electric field type non-isothermal liquid bridge generator as described in claim 1, characterized in that: It also includes a synchronous transmission bracket (11), which is a U-shaped structure. The two sides of the synchronous transmission bracket (11) are respectively installed in the openings on the active bearing (9) and the driven bearing (10), and are fixed by bolts in the threaded round holes on the side, so that the active bearing (9) drives the driven bearing (10) to rotate synchronously through the synchronous transmission bracket (11).

7. The externally applied electric field type non-isothermal liquid bridge generator as described in claim 3, characterized in that: The fixed shaft (12) includes a shaft body (12-1), a threaded head (12-2), a square clamp (12-3), a retaining ring (12-4), and a retaining strip (12-5). The shaft body (12-1) has a cylindrical structure. The front and rear ends of the shaft body (12-1) are respectively provided with a square clamp (12-3) and a threaded head (12-2). The square clamps (12-3) on both sides are respectively installed in the square grooves provided in the fixed shaft bracket connecting hole (18) and the inner bracket connecting hole (19) to fix and limit the shaft. The shaft (12) rotates, and the upper part of the fixed shaft bracket connecting hole (18) is an open opening to facilitate the disassembly of the fixed shaft (12); a retaining ring (12-4) is provided on the shaft body (12-1), and multiple retaining strips (12-5) are provided on the inner side of the retaining ring (12-4). The retaining strips (12-5) are inserted into the retaining grooves on the inner side of the active stator (9-1) in the active bearing (9) or the driven stator (10-1) in the driven bearing (10) to prevent the rotation of the active stator (9-1) or the driven stator (10-1).

8. The externally applied electric field type non-isothermal liquid bridge generator as described in claim 1, characterized in that: The upper plate assembly (1) and the lower plate assembly (2) are made of aluminum nitride ceramic material.

9. The externally applied electric field type non-isothermal liquid bridge generator as described in claim 2, characterized in that: The upper bridge seat (3), lower bridge seat (4), inner support (6), and electrode plate support (8) are made of polyethylene resin.

10. The method for measuring liquid bridges using an externally applied electric field-type non-isothermal liquid bridge generator as described in any one of claims 1-9, characterized in that: The experimental liquid is injected between the upper plate (1-1) and the lower plate (2-1) so that the liquid bridge maintains the interface shape through surface tension. The temperature control device is turned on to heat the upper plate of the liquid bridge at a constant temperature and cool the lower plate of the liquid bridge at a constant temperature, so as to form a temperature difference between the upper and lower plates. The electric field device is turned on, and the electric field strength is controlled by connecting the power supply through the electrode plate (7). The electric field angle is controlled by the rotating motor (15) to obtain the electric field conditions required for the experiment. The dynamic deformation of the free surface of the liquid bridge is captured by a high-speed camera, or the laser sheet light source is used to penetrate the liquid bridge along the central axis of the liquid bridge to illuminate the two-dimensional plane where the laser sheet light source is located. Then, the high-speed camera is used to capture the tracer particles illuminated by the laser in the two-dimensional plane to obtain the flow state inside the liquid bridge.

Images