Air film flow field pressure testing device

Abstract

The application discloses a gas film flow field pressure testing device and particularly relates to the technical field of gas bearing detection, comprising a rack, wherein a testing assembly is arranged on the rack; the testing assembly comprises a testing table arranged on the rack; two bases are arranged at the bottom of the inner cavity of the testing table; and a pressurizing block for testing a test piece is arranged at the two ends of each base. The application can flexibly adapt to gas bearing test pieces with different outer diameters and different groove parameters by adjusting the deflection angle of the hinge piece through the lead screw, cooperating with the arc-shaped constraint groove of the pressurizing block and the self-resetting structure. The adaptability not only relies on the standardized testing logic formed through collaborative research and development, but also in turn enables the testing capacity of precise data and panoramic working conditions to cover more application scenarios, forming the closed-loop advantages of precision, comprehensiveness, efficiency and practicality, and significantly improving the industrial application value of the device.

Description

Technical Field

[0001] This invention relates to the field of gas bearing testing technology, and more specifically, to a gas film flow field pressure testing device. Background Technology

[0002] In recent years, the rapid development of aerospace, defense equipment, high-end medical care, and space exploration has placed more stringent demands on the performance of high-speed rotating machinery. Gas bearings, as core components of high-speed rotating machinery, have become an indispensable part of high-end equipment due to their outstanding advantages such as high speed, high precision, low friction, no noise, minimal vibration, cleanliness, environmental friendliness, and immunity to harsh environments. However, gas bearings generally suffer from low load-bearing capacity and insufficient rigidity, which greatly limits their application in a wider range of high-end scenarios. Therefore, in-depth research into the dynamic and static characteristics of gas bearings and accurate acquisition of gas film-related performance parameters are crucial for improving their performance.

[0003] Film pressure is a core parameter that determines the critical performance of gas bearings, such as load capacity, stiffness, and damping. Currently, the industry mainly calculates film pressure by solving the Reynolds equation using the finite element method or the finite difference method. However, such calculation methods require multiple approximations in the physical model and mathematical derivation, resulting in significant deviations between the calculated film pressure and derived performance parameters and the actual working conditions. This makes it impossible to provide accurate support for the structural design and parameter optimization of gas bearings.

[0004] Meanwhile, existing methods for testing film pressure have significant limitations: on the one hand, pure physical testing requires the construction of complex experimental platforms, resulting in high specimen processing costs, long testing cycles, and difficulty in accurately simulating complex working conditions such as vibration and obstruction in actual operation, thus failing to fully capture the dynamic changes in film pressure; on the other hand, while standalone simulation analysis can quickly obtain data through 3D modeling and numerical calculation, it neglects real factors such as airflow disturbances and component assembly errors in actual testing, and the simulation of thermo-fluid-structure interaction effects is disconnected from actual working conditions, leading to insufficient reliability of simulation results. Furthermore, existing technologies fail to effectively integrate physical testing with simulation analysis, making it impossible to optimize test conditions and reduce redundant experiments through simulation, and also difficult to verify the accuracy of simulation models through physical testing. This results in low efficiency in the research of film sealing performance, severely hindering the development of gas bearings.

[0005] Therefore, there is an urgent need for a testing device that can integrate the advantages of physical testing and simulation analysis, accurately simulate complex working conditions, and quickly obtain real and comprehensive air film flow field pressure data, so as to solve the technical problems of large data deviation, incomplete working condition coverage, and low R&D efficiency in the existing technology. Summary of the Invention

[0006] In order to overcome the above-mentioned defects of the prior art, the present invention provides an air film flow field pressure testing device, which aims to solve the problems mentioned in the background art.

[0007] The present invention provides the following technical solution: a film flow field pressure testing device, including a frame, on which testing components are arranged;

[0008] The testing assembly includes a testing platform mounted on a frame. The bottom of the inner cavity of the testing platform is provided with two bases, and each base is provided with a pressure block at both ends for testing the specimen. The vertical cross-sectional shape of one side of each pressure block is arc-shaped, and the arc-shaped surface of the pressure block is provided with several constraint grooves. The pressure block is deflected so that the constraint grooves abut against the outside of the specimen to test the specimen.

[0009] The specimen includes a rotating ring and a stationary ring, which are stacked together. The bottom of the rotating ring and the top of the stationary ring are respectively provided with abutting rings. The abutting rings abut against the constraint groove. The abutting ring at the bottom of the rotating ring abuts against the constraint groove and constrains the rotating ring first. The abutting ring at the top of the stationary ring abuts against the constraint groove, causing the pressure block to be deflected by force and clamp the stationary ring.

[0010] The top of the moving ring is provided with several blades, and the cross-sectional shape of each blade is set to arc. The airflow is guided by the arc-shaped cross-section of the blade, so that the moving ring can rotate by the traction force conveyed by the airflow.

[0011] Optionally, in a possible implementation, the test assembly further includes several bearing seats respectively disposed at one end of the base, and each bearing seat is rotatably connected to a rotating shaft. First connecting ears are fixedly disposed at both ends of the rotating shaft. A hinge member is hinged to the first connecting ear, and a lead screw is threaded onto the hinge member. The lead screw extends to the hinge member, and by rotating the lead screw, the deflection angle of the hinge member is adjusted, thereby pulling the rotating shaft to deflect, which is used to adjust the stroke of the rotating shaft's rotation radius. A second connecting ear is rotatably connected to the rotating shaft, and one end of the second connecting ear extends to the outside of the pressure block and is fixedly connected to the pressure block. The pressure block is rotatably connected to the rotating shaft, allowing the pressure block and the second connecting ear to rotate along the connection between the pressure block and the rotating shaft, so that the two pressure blocks deflect against the outside of the moving ring and the stationary ring. A pressure plate is fixedly disposed on the side of the pressure block away from the constraint groove. By pressing the pressure plate, the pressure block is deflected by force, which is used to reset the constraint on the moving ring and the stationary ring by the weight of the pressure plate and the pressure block itself.

[0012] Optionally, in a possible implementation, a first hydraulic rod is provided at the top of the inner cavity of the test bench. The first hydraulic rod is located directly above the base, and a gas-gathering hood is provided at the output end of the first hydraulic rod. A pressure sensor is provided in the middle of the gas-gathering hood, and the bottom end of the pressure sensor abuts against the moving ring. The first hydraulic rod drives the gas-gathering hood and the pressure sensor to move downward so that the pressure sensor abuts against the moving ring for pressure testing. A miniature air pump for blowing air is provided at the top of the gas-gathering hood, and a pressure sensor is provided at the top of the pressure sensor. Several elastic connecting rods are provided on the outside of the pressure sensor, and a level is provided at one end of each of the elastic connecting rods. The pressure sensor is located outside the gas-gathering hood. The bottom end of the pressure sensor passes through the stationary ring and abuts against the moving ring. The elastic connecting rod deforms under force to contact the bottom end of the ring, which can then contact the middle of the moving ring to make a slight adjustment of the moving ring's position, simulating obstruction. A display instrument is set on one side of the top of the frame, and a second hydraulic rod is set on one side of the display instrument. The second hydraulic rod is bolted to the frame, and a displacement sensor is set at the output end of the second hydraulic rod. A slide is set on the displacement sensor, which is located at the bottom of the base. The second hydraulic rod drives the displacement sensor to move the slide and the base, causing the moving and stationary rings to swing slightly, simulating vibration.

[0013] The technical effects and advantages of this invention are as follows:

[0014] 1. This invention effectively avoids test interference caused by airflow leakage, contact deviation, and rotational vibration by using a vertical contact design of the pressure sensor, the stabilizing and buffering effect of the elastic connecting rod, and the verticality calibration mechanism of the level, combined with the closed flow field structure of the gas-gathering hood. At the same time, it abandons the multiple physical approximations in traditional calculation methods and directly captures the real pressure signal of the air film between the moving ring and the stationary ring. This solves the core pain point of large deviation between traditional test data and actual working conditions, and provides highly reliable data support for subsequent working condition simulation and performance derivation. It is the basic prerequisite for realizing subsequent functions.

[0015] 2. Relying on precise basic data acquisition capabilities, this invention further expands the scope of operating conditions covered. Through a reciprocating slide mechanism driven by a second hydraulic rod, it accurately simulates the vibration environment of a gas bearing during actual operation. Utilizing the controllable deformation of the elastic connecting rod, it recreates obstruction scenarios caused by installation deviations or wear. Simultaneously, it links the thermal, fluid, and solid-state coupling analysis in the simulation, achieving the correlation capture of pressure, temperature, and stress fields. This design overcomes the shortcomings of traditional testing methods, such as limited testing conditions and a disconnect between simulation and reality, upgrading gas film performance analysis from a static single-point to a dynamic panoramic view. Precise basic data ensures the comparability of test results under different operating conditions, providing a complete data chain for comprehensively evaluating the reliability of gas bearings.

[0016] 3. Based on precise physical test data and panoramic operating condition simulation results, this invention achieves deep synergy between physical testing and simulation analysis. On the one hand, the simulation model is calibrated using physical test data to correct real-world factors such as airflow disturbances and assembly errors that are ignored in traditional simulations, thus improving the reliability of the simulation results. On the other hand, the optimized simulation model guides the adjustment of test parameters, clarifies key test conditions and core monitoring points, and reduces redundant experiments and the loss of high-cost test pieces. This collaborative mode of testing to verify simulation and simulation to optimize testing solves the problem of long development cycles and low efficiency caused by the separation of the two in traditional technologies. Supported by precise data and panoramic operating conditions, it accelerates the structural design and parameter optimization process of gas bearings.

[0017] In summary, based on the aforementioned precise data, comprehensive operating conditions, and collaborative research and development, this invention, through the adjustment of the hinge angle by a lead screw, combined with the arc-shaped constraint groove and self-realigning structure of the pressure block, can flexibly adapt to gas bearing specimens with different outer diameters and groove parameters. Simultaneously, the modular hydraulic rods and sensor components support functional expansion, meeting the personalized testing needs of gas bearings in various fields such as aerospace, high-end medical, and defense equipment. This adaptability relies on the standardized testing logic formed through collaborative research and development, and in turn, allows the precise data and comprehensive operating condition testing capabilities to cover more application scenarios, forming a closed-loop advantage of precision, comprehensiveness, efficiency, and practicality, significantly enhancing the industrial application value of the device. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in this disclosure, the accompanying drawings used in some embodiments will be briefly described below. Obviously, the drawings described below are only drawings of some embodiments of this disclosure, and those skilled in the art can obtain other drawings based on these drawings. In addition, the drawings described below can be regarded as schematic diagrams and are not intended to limit the actual size of the product, the actual flow of the method, the actual timing of the signals, etc. involved in the embodiments of this disclosure.

[0019] Figure 1 This is a front view of the overall structure of the present invention.

[0020] Figure 2 This is a side view of the base, pressure block, moving ring, stationary ring, first connecting ear, hinge, and lead screw of the present invention.

[0021] Figure 3 This is a schematic diagram of the moving ring, stationary ring, contact ring, and blade of the present invention.

[0022] Figure 4 This is a schematic diagram of the base, first connecting ear, hinge, pressure block and constraint groove of the present invention.

[0023] Figure 5This is a schematic diagram of the first connecting ear, hinge, lead screw, second connecting ear, pressure block, rotating shaft and constraint groove of the present invention.

[0024] Figure 6 This is a schematic diagram of the bearing housing, base, first connecting lug, lead screw, and second connecting lug of the present invention.

[0025] Figure 7 This is a top view of the overall structure of the present invention.

[0026] Figure 8 This is a schematic diagram of the gas-gathering hood, pressure sensor, pressure rod, elastic connecting rod, and level of the present invention.

[0027] Figure 9 This is a schematic diagram of the air film of the present invention.

[0028] Figure 10 This is a schematic diagram of the air film pressure cloud diagram of the present invention.

[0029] Figure 11 This is a schematic diagram of the temperature and pressure field import contour plot of the present invention.

[0030] Figure 12 This is a schematic diagram of the total deformation stress cloud of the specimen of the present invention.

[0031] The attached figures are labeled as follows: 1. Frame; 2. Test bench; 3. Base; 4. Pressure block; 5. Constraint groove; 6. Moving ring; 7. Stationary ring; 8. Contact ring; 9. Blade; 10. Bearing seat; 11. Rotating shaft; 12. First connecting lug; 13. Hinge; 14. Lead screw; 15. Second connecting lug; 16. First hydraulic rod; 17. Gas condenser; 18. Pressure sensor; 19. Pressure rod; 20. Elastic connecting rod; 21. Level; 22. Display; 23. Second hydraulic rod; 24. Displacement sensor; 25. Slide table; 26. Miniature air pump. Detailed Implementation

[0032] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0033] Example 1

[0034] This embodiment discloses the specific usage process of a gas film flow field pressure testing device, aiming to achieve real-time detection of gas bearing gas film flow field pressure through precise structural fit and step-by-step operation, while simulating both normal and special working conditions in actual operation to ensure the authenticity and comprehensiveness of the test data:

[0035] First, set up rack 1, as shown in the attached diagram. Figure 1 and attached Figure 7As shown, the frame 1 is welded from high-strength aluminum alloy, and anti-slip pads are installed at the bottom to ensure stability during the test. The test platform 2 is fixedly installed in the middle of the frame 1. The test platform 2 is a rectangular cavity structure with an open top. Two bases 3 are symmetrically fixed to the bottom of the cavity with bolts. The distance between the two bases 3 is adapted to the outer diameter of the moving ring 6 and the stationary ring 7 of the specimen, ensuring that the specimen is centered on the test platform 2 after installation.

[0036] As attached Figure 2 , 4 As shown in Figure 6, bearing seats 10 are fixedly installed at both ends of each base 3 by bolts. The inner cavity of the bearing seat 10 is inlaid with a deep groove ball bearing. The rotating shaft 11 passes through the deep groove ball bearing and is rotatably connected to the bearing seat 10. The first connecting ears 12 are welded and fixed at both ends of the rotating shaft 11. The first connecting ears 12 are provided with hinge holes.

[0037] As attached Figure 5 As shown, a hinge member 13 is hinged in the hinge hole of the first connecting ear 12. A threaded through hole is provided in the middle of the hinge member 13. The screw 14 passes through the threaded through hole and is threadedly connected to the hinge member 13. By rotating the screw 14 clockwise or counterclockwise, the hinge member 13 can be driven to deflect around the hinge point of the first connecting ear 12, thereby pulling the rotating shaft 11 to rotate slightly along the bearing hole of the bearing seat 10, so as to realize the stroke adjustment of the rotation radius of the rotating shaft 11.

[0038] As attached Figure 2 , 5 As shown, a second connecting lug 15 is installed in the middle of the rotating shaft 11. The free end of the second connecting lug 15 extends to the outside of the pressure block 4 and is fixedly connected to the pressure block 4 by welding. The middle of the pressure block 4 is rotatably connected to the rotating shaft 11 through a bearing sleeve, so that the pressure block 4 can rotate around the axis of the rotating shaft 11. The vertical section of the pressure block 4 near the specimen is arc-shaped, and several constraint grooves 5 are evenly opened on the arc-shaped surface. The width of the constraint grooves 5 is consistent with the thickness of the contact ring 8 on the specimen, as shown in the attached figure. Figure 4 , 5 As shown. At the same time, a rectangular pressure plate is welded and fixed on the side of the pressure block 4 away from the constraint groove 5. By pressing the pressure plate, the pressure block 4 can be driven to deflect around the rotating shaft 11. After being released, it can be reset by the weight of the pressure plate and the pressure block 4 itself.

[0039] As attached Figure 1 , 8As shown, a first hydraulic rod 16 is fixedly installed on the top of the inner cavity of the test bench 2 via a bracket. The axis of the first hydraulic rod 16 coincides with the symmetrical center line of the two bases 3, that is, it is located directly above the specimen. The output end of the first hydraulic rod 16 is fixedly connected to the gas-gathering hood 17 via a flange. The gas-gathering hood 17 has an inverted conical structure, and its inner wall is lined with sound-insulating cotton to reduce airflow noise interference. The top is connected to a micro air pump 26 via an air pipe. A mounting hole is opened in the middle of the gas-gathering hood 17, and the top of the pressure sensor 18 is fixed in the mounting hole by bolts. The pressure sensor 18 is model PT124G-111, and its bottom end is a hemispherical contact head. Several elastic connecting rods 20 are evenly distributed on the outside of the pressure sensor 18. One end of the elastic connecting rod 20 is connected to the outer shell of the pressure sensor 18 via a hinge, and the other end is fixed to a level 21 via bolts. The level 21 is a bubble level, and the level 21 is located on the outside of the gas-gathering hood 17 to facilitate observation of the verticality of the pressure sensor 18. (See attached figure) Figure 8 As shown.

[0040] As attached Figure 1 , 7 As shown, a display 22 is fixedly mounted on one side of the top of the frame 1 with bolts. The display 22 is electrically connected to the pressure sensor 18 and the displacement sensor 24 via a data cable and is used to display pressure data and displacement data in real time. On the other side of the top of the frame 1, a second hydraulic rod 23 is fixed with bolts. The output end of the second hydraulic rod 23 is connected to the displacement sensor 24 via a coupling. The displacement sensor 24 is a KTC-100 model. The free end of the displacement sensor 24 is fixed to the slide table 25 with bolts. The top of the slide table 25 is fixedly connected to the bottom of the base 3 with bolts. The slide table 25 can slide back and forth along the guide rail at the bottom of the test table 2.

[0041] The specimen in this embodiment includes a moving ring 6 and a stationary ring 7, both made of silicon carbide. The outer diameter of the stationary ring 7 is the same as that of the moving ring 6. (See attached...) Figure 3 As shown, an annular contact ring 8 is integrally formed on the bottom edge of the moving ring 6, and an contact ring 8 is also integrally formed on the top edge of the stationary ring 7; several blades 9 are evenly distributed on the top of the moving ring 6, the cross-section of the blades 9 is arc-shaped, and the blades 9 are integrally formed with the moving ring 6.

[0042] Place the stationary ring 7 horizontally at the top center of the two bases 3, then stack the moving ring 6 on top of the stationary ring 7, ensuring that the axes of the moving ring 6 and the stationary ring 7 coincide. Next, press the pressure plates on both sides of the pressure blocks 4, causing the pressure blocks 4 to deflect around the axis 11 towards the specimen until the abutment ring 8 at the bottom of the moving ring 6 is embedded in the constraint groove 5 of the pressure block 4. At this point, the pressure block 4 first forms a radial constraint on the moving ring 6. Continue pressing the pressure plates, and the abutment ring 8 at the top of the stationary ring 7 is simultaneously embedded in the constraint groove 5. Under the action of the abutment force, the pressure block 4 further deflects and clamps the stationary ring 7. After releasing the pressure plates, the specimen is held in a clamped state by the weight of the pressure plates and the pressure blocks 4 themselves, achieving stable positioning. (See attached diagram.) Figure 2 , 3 As shown.

[0043] The specific working principle is as follows: Rotating the lead screw 14 adjusts the deflection angle of the hinge 13: When the lead screw 14 is rotated clockwise, the hinge 13 deflects towards the base 3, pulling the rotating shaft 11 clockwise, which in turn drives the two pressure blocks 4 to clamp further towards the specimen, increasing the constraint force; when the lead screw 14 is rotated counterclockwise, the hinge 13 deflects away from the base 3, the rotating shaft 11 rotates counterclockwise, and the constraint force of the pressure blocks 4 decreases. This adjustment can accommodate specimens with different outer diameters, as shown in the attached diagram. Figure 5 , 6 As shown.

[0044] Activate the first hydraulic rod 16 to drive the gas-gathering hood 17 to slowly move downwards. Observe the position of the bubble on the level 21. If the bubble deviates, adjust the deformation of the elastic connecting rod 20. The elastic connecting rod 20 is made of spring steel and can achieve ±5° deformation adjustment to keep the axis of the pressure sensor 18 aligned with the axis of the specimen. Ensure that the bottom end of the pressure sensor 18 is vertically abutting against the top center of the moving ring 6. After debugging, close the first hydraulic rod 16, allowing the gas-gathering hood 17 to remain above the specimen. (See attached diagram) Figure 8 As shown.

[0045] Check whether the circuit connections of the miniature air pump 26, pressure sensor 18, displacement sensor 24, and display 22 are normal. Start the display 22 to perform zero-point calibration and ensure that the data transmission of each sensor is accurate.

[0046] When the micro air pump 26 is started, the airflow is guided by the air-gathering shroud 17 and blown evenly onto the blade 9 at the top of the moving ring 6. Since the cross-section of the blade 9 is arc-shaped, the airflow forms a pressure difference on the surface of the blade 9, generating a traction force to drive the moving ring 6 to rotate around its own axis. The rotation speed can be detected by an external speed measuring instrument.

[0047] The first hydraulic rod 16 is activated, driving the gas-gathering shroud 17 to move downwards until the bottom hemispherical contact head of the pressure sensor 18 touches the top center of the moving ring 6. At this point, the first hydraulic rod 16 stops moving. The gas-gathering shroud 17 completely covers the outside of the moving ring 6 and the stationary ring 7, forming a closed air film flow field space to prevent air leakage from affecting the test accuracy, as shown in the attached figure. Figure 1 , 8 As shown.

[0048] During the rotation of the moving ring 6, an air film is formed between it and the stationary ring 7. The air film pressure acts on the bottom of the moving ring 6 and is transmitted to the pressure sensor 18. The pressure sensor 18 converts the pressure signal into an electrical signal and transmits it to the display 22 in real time. The display 22 records the pressure data in digital and curve form and obtains the dynamic change curve of the air film flow field pressure.

[0049] During the test, the elastic connecting rod 20 is always in a state of slight deformation. Its elastic force can counteract the radial vibration generated by the rotation of the moving ring 6, ensuring the contact stability between the pressure sensor 18 and the moving ring 6, and further improving the accuracy of the test data.

[0050] The second hydraulic rod 23 is activated, and the reciprocating displacement amplitude at the output end is set to ±2mm. The second hydraulic rod 23 drives the displacement sensor 24, causing the slide table 25 and the base 3 to slide back and forth along the guide rail at the bottom of the test bench 2. This causes the moving ring 6 and the stationary ring 7 to produce a slight reciprocating swing amplitude, simulating the vibration environment of the gas bearing in actual operation, as shown in the attached figure. Figure 7 As shown; simultaneously, pressure sensor 18 and displacement sensor 24 synchronously collect air film pressure data and vibration displacement data, and display instrument 22 records the correlation curve between the two to analyze the influence law of vibration on air film pressure.

[0051] By adjusting the deformation of the elastic connecting rod 20, it contracts inward, pushing the bottom end of the pressure sensor 18 to one side, thereby fine-tuning the position of the moving ring 6. This simulates the obstruction situation of the gas bearing caused by installation deviation or wear during actual operation, as shown in the attached diagram. Figure 8 As shown; keeping the air flow rate of the micro air pump 26 constant, the pressure sensor 18 continuously collects air film pressure data and analyzes the distribution changes of air film pressure under obstructed conditions.

[0052] After the test is completed, the micro air pump 26, the first hydraulic rod 16, the second hydraulic rod 23 and the display 22 are turned off. The air film pressure data, displacement data and correlation curves under normal working conditions, vibration working conditions and obstructed working conditions stored in the display 22 are exported. By comparing the test data under different working conditions, the static value, dynamic fluctuation range and the degree of influence of external factors of the air film flow field pressure of the gas bearing can be accurately obtained, providing accurate experimental data support for the study of the dynamic and static characteristics of the gas bearing.

[0053] Example 2

[0054] Based on Example 1, such as Figure 9 and 10 As shown;

[0055] Table 1 Structural parameters of the air-film sealing dynamic ring and air film.

[0056]

[0057] Table 2 Material parameters of dynamic and static rings

[0058]

[0059] The steady-state performance parameters of the air-supported membrane include the opening force, leakage rate, membrane stiffness, and stiffness-to-leakage ratio. The formula for calculating the opening force is shown below:

[0060] ;

[0061] Where F0 is the opening force, N; ρ is the pressure of the air film on a certain point on the sealing end face, Pa; R0 and RI are the inner and outer diameters of the end face, respectively, mm.

[0062] The formula for calculating leakage is as follows:

[0063] ;

[0064] θ is the angle of the solution region; δ is the thickness of the gas film, in μm; Q is the leakage rate, in kg·s⁻¹.

[0065] The formula for calculating air film stiffness is as follows:

[0066] ;

[0067] Where K is the air film stiffness, N·um-1; δ is the air film thickness, μm; and F0 is the opening force, N.

[0068] The formula for calculating the stiffness-to-leakage ratio is as follows:

[0069] ;

[0070] in, The ratio of rigid leakage is N·s·kg⁻¹um⁻¹.

[0071] In this embodiment, the parameters of the moving ring 6 and stationary ring 7 of the specimen were determined based on 3D modeling and simulation optimization. The specific parameters are as follows: the moving ring 6 is made of structural steel, with an inner radius r0 = 12.5 mm, an outer radius r2 = 25 mm, and a thickness of 10 mm; the inner radius of the spiral groove region is r1 = 17.5 mm, the spiral angle is 20°, the groove width ratio is 0.5, and the groove length ratio is 0.6; the stationary ring 7 is made of impregnated graphite, with an outer diameter of 25 mm (the same as the moving ring 6) and a thickness of 8 mm; as shown in the attached... Figure 3 As shown, an annular contact ring 8 is integrally formed on the bottom edge of the moving ring 6, and an contact ring 8 is also integrally formed on the top edge of the stationary ring 7. The contact ring 8 has a width of 5 mm and a thickness of 2 mm. Several blades 9 are evenly distributed on the top of the moving ring 6. The cross-section of the blades 9 is arc-shaped with an arc of 120°. The height of the blades 9 is 15 mm, and the spacing between adjacent blades 9 is 60°. The blades 9 are integrally formed with the moving ring 6.

[0072] The moving ring 6 has a density of 7.85 g / cm³, an elastic modulus of 206 GPa, a Poisson's ratio of 0.3, a thermal conductivity of 60 W / (m·K), and a coefficient of thermal expansion of [missing information]. The density of static ring-impregnated graphite is 2.0 g / cm³, elastic modulus is 15 GPa, Poisson's ratio is 0.25, thermal conductivity is 70 W / (m·K), and coefficient of thermal expansion is... This ensures that the material of the test specimen is consistent with the simulation model, thereby reducing systematic errors in testing and simulation.

[0073] Place the stationary ring 7 horizontally at the top center of the two bases 3, then stack the rotating ring 6 on top of the stationary ring 7, ensuring that the axes of the rotating ring 6 and the stationary ring 7 coincide, and that the air film gap h1 = 10 μm and the groove depth h2 = 5 μm are formed between them; then, press the pressure plates on the pressure blocks 4 on both sides, causing the pressure blocks 4 to deflect around the rotating shaft 11 toward the specimen until the abutment ring 8 at the bottom of the rotating ring 6 is embedded in the constraint groove 5 of the pressure block 4. At this time, the pressure block 4 first forms a radial constraint on the rotating ring 6; continue to press the pressure plates, and the abutment ring 8 at the top of the stationary ring 7 is simultaneously embedded in the constraint groove 5. Under the action of the abutment force, the pressure block 4 further deflects and clamps the stationary ring 7. After releasing the pressure plates, the clamping state is maintained by the weight of the pressure plates and the pressure blocks 4 themselves, achieving a stable positioning of the specimen, as shown in the attached figure. Figure 2 , 3 As shown.

[0074] The micro air pump 26 is started, and the air flow rate is set to 30 L / min. After being guided by the air-gathering hood 17, the airflow is evenly blown onto the blades 9 at the top of the moving ring 6. Since the cross-section of the blades 9 is arc-shaped, the airflow forms a pressure difference on the surface of the blades 9, generating a traction force that drives the moving ring 6 to rotate around its own axis. The rotation speed is stabilized at 2 × 10⁻⁶. 4 The speed is monitored in real time by an external tachometer and adjusted accordingly.

[0075] The first hydraulic rod 16 is activated, and the displacement speed at the output end is set to 5 mm / s. This drives the gas-gathering shroud 17 to move downwards until the bottom hemispherical contact head of the pressure sensor 18 touches the top center of the moving ring 6. At this point, the first hydraulic rod 16 stops moving. The gas-gathering shroud 17 completely covers the outside of the moving ring 6 and the stationary ring 7, forming a closed air film flow field space to prevent air leakage from affecting the test accuracy. (See attached diagram.) Figure 1 , 8 As shown.

[0076] During the rotation of the moving ring 6, an air film is formed between it and the stationary ring 7. The air film pressure acts on the bottom of the moving ring 6 and is transmitted to the pressure sensor 18. The pressure sensor 18 converts the pressure signal into an electrical signal and transmits it to the display 22 in real time. At the same time, the formula is set to calculate the steady-state performance parameters of the air film.

[0077] Air film opening force Calculation of pressure distribution on the sealing end face using an integrated gas film =∫∫ρdA, where ρ is the gas film pressure and A is the area of ​​the sealing end face. , These are the outer diameter and inner diameter of the end face, respectively.

[0078] Leakage Q: Calculated based on parameters such as gas film thickness and solution region angle, Q=∫(θδ)dv, where θ is the solution region angle and δ is the gas film thickness;

[0079] Air film stiffness K: Calculated from the relationship between opening force and air film thickness. K = / Δδ;

[0080] Rigidity-to-leakage ratio: The rigidity-to-leakage ratio is calculated by the ratio of air film stiffness to leakage rate = K / Q.

[0081] The test lasted 10 minutes, with data collected every 1 second to obtain the dynamic change curve of the air film flow field pressure. Simultaneously, calculated parameters such as opening force, leakage, air film stiffness, and stiffness-to-leakage ratio were recorded and compared with simulation results. Figure 10 As shown, the validity of the physical test data is verified.

[0082] During the test, the elastic connecting rod 20 is always in a state of slight deformation. Its elastic force can counteract the radial vibration generated by the rotation of the moving ring 6, ensuring the contact stability between the pressure sensor 18 and the moving ring 6, and further improving the accuracy of the test data.

[0083] Solid heat transfer parameters include fixed temperature, initial temperature value, and heat flux boundary conditions.

[0084] The conservation equations for solids are as follows:

[0085] ;

[0086] in, Density of solid; For Cauchy stress tensor; This is the local acceleration vector in the solid domain; It is a volume force vector.

[0087] The energy transfer equation in the solid region is:

[0088] ;

[0089] The left side of the equation represents the convective energy transfer caused by the motion of the solid; the right side represents the heat flow caused by thermal conduction and the possible heat sources inside the solid. The absolute velocity vector of the solid; Enthalpy; The thermal conductivity of a solid is W / (m·K). It is a possible heat source inside the solid.

[0090] The heat conduction equation of the moving ring is shown below:

[0091] ;

[0092] In the formula: ksr is the thermal conductivity of the moving ring, W / (m·K); ρr is the density of the moving ring, kg / m3; cr is the specific heat capacity of the moving ring, J ( / kg·K); vsx is the component velocity of the moving ring in the x-direction, m / s; vsy is the component velocity of the moving ring in the y-direction, m / s; Tr is the temperature of the moving ring, K.

[0093] The heat conduction equation for the stationary ring is shown below:

[0094] ;

[0095] In the formula: kss is the thermal conductivity of the stationary ring, W / (m·K); Ts is the temperature of the moving ring, K.

[0096] The fluid-structure interaction governing equations are as follows:

[0097] ;

[0098] In the formula: subscript f represents fluid; subscript s represents solid; q represents heat flow; T represents temperature; Forces acting on fluids; denoted as σ0, where σ0 is the solid stress and z is

[0099] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A film flow field pressure testing device, comprising a frame (1), characterized in that: The test components are mounted on the rack (1); The test assembly includes a test bench (2) mounted on a frame (1). The bottom of the inner cavity of the test bench (2) is provided with two bases (3), and each base (3) has a pressure block (4) at both ends for testing the specimen. The vertical cross-section of one side of each pressure block (4) is arc-shaped, and the arc-shaped surface of the pressure block (4) is provided with several constraint grooves (5). The pressure block (4) is deflected so that the constraint grooves (5) abut against the outside of the specimen to test the specimen. The specimen includes a moving ring (6) and a stationary ring (7). The moving ring (6) and the stationary ring (7) are stacked, and the bottom of the moving ring (6) and the top of the stationary ring (7) are respectively provided with abutting rings (8). The abutting rings (8) abut against the constraint groove (5). The abutting ring (8) at the bottom of the moving ring (6) abuts against the constraint groove (5) and constrains the moving ring (6) first. The abutting ring (8) at the top of the stationary ring (7) abuts against the constraint groove (5) and causes the pressure block (4) to be deflected by force and clamp the stationary ring (7). The top of the moving ring (6) is provided with several blades (9), and the cross-sectional shape of each blade (9) is set to be arc-shaped. The airflow is guided by the arc-shaped cross-section of the blade (9) so that the moving ring (6) can rotate by the traction force conveyed by the airflow. The test bench (2) has a first hydraulic rod (16) at the top of its inner cavity. The first hydraulic rod (16) is located directly above the base (3), and the output end of the first hydraulic rod (16) is provided with a gas-gathering hood (17). A pressure sensor (18) is provided in the middle of the gas-gathering hood (17). The bottom end of the pressure sensor (18) abuts against the moving ring (6). The first hydraulic rod (16) drives the gas-gathering hood (17) and the pressure sensor (18) to move downward so that the pressure sensor (18) abuts against the moving ring (6) to perform pressure testing. A miniature air pump (26) for blowing air is provided at the top of the gas-gathering hood (17). The pressure sensor (18) is provided on the top of the pressure sensor (18). Several elastic connecting rods (20) are provided on the outside of the pressure sensor (18). A level (21) is provided at one end of each elastic connecting rod (20). The level (21) is located on the outside of the gas gathering hood (17). The bottom end of the pressure sensor (18) passes through the stationary ring (7) and abuts against the moving ring (6). The elastic connecting rod (20) is deformed under force to abut against the bottom end of the ring (8) and can contact the middle of the moving ring (6) to make the position of the moving ring (6) slightly adjusted to simulate the obstruction situation.

2. The air film flow field pressure testing device according to claim 1, characterized in that: The test assembly also includes several bearing seats (10) respectively disposed at one end of the base (3), and each bearing seat (10) is rotatably connected to a rotating shaft (11), and the two ends of the rotating shaft (11) are respectively fixedly provided with a first connecting ear (12).

3. The air film flow field pressure testing device according to claim 2, characterized in that: The first connecting ear (12) is hinged with a hinge (13), and the hinge (13) is threaded with a screw (14). The screw (14) extends to the hinge (13). By rotating the screw (14), the deflection angle of the hinge (13) is adjusted, which in turn pulls the shaft (11) to deflect, thereby adjusting the stroke of the shaft (11) rotation radius.

4. The air film flow field pressure testing device according to claim 3, characterized in that: A second connecting ear (15) is fixedly rotatably connected to the rotating shaft (11). One end of the second connecting ear (15) extends to the outside of the pressure block (4) and is fixedly connected to the pressure block (4). The pressure block (4) is rotatably connected to the rotating shaft (11), so that the pressure block (4) and the second connecting ear (15) can rotate along the connection between the pressure block (4) and the rotating shaft (11), so that the two pressure blocks (4) are biased against each other on the outside of the moving ring (6) and the stationary ring (7).

5. The air film flow field pressure testing device according to claim 1, characterized in that: A pressure plate is fixedly installed on the side of the pressure block (4) away from the constraint groove (5). By pressing the pressure plate, the pressure block (4) is deflected by force, which is used to reset the dynamic ring (6) and the static ring (7) by the weight of the pressure plate and the pressure block (4) itself.

6. The air film flow field pressure testing device according to claim 1, characterized in that: A display device (22) for display is provided on one side of the top of the frame (1), and a second hydraulic rod (23) is provided on one side of the display device (22).

7. The air film flow field pressure testing device according to claim 6, characterized in that: The second hydraulic rod (23) is bolted to the frame (1). The output end of the second hydraulic rod (23) is equipped with a displacement sensor (24). The displacement sensor (24) is equipped with a slide (25). The slide (25) is located at the bottom of the base (3). The displacement sensor (24) driven by the second hydraulic rod (23) moves the slide (25) and the base (3) to cause the moving ring (6) and the stationary ring (7) to have a slight reciprocating swing amplitude, which is used to simulate the vibration situation.

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