A method and system for determining a membrane deformation curve of a thin film restrictor

Abstract

This invention discloses a method and system for determining the deformation curve of a thin-film throttling device diaphragm, belonging to the field of thin-film throttling device technology. The method includes: 1) establishing a finite element model of the thin-film throttling device; 2) performing fluid-structure interaction simulation analysis under different operating conditions based on the established finite element model; 3) extracting the full-field deformation of the diaphragm under each operating condition based on the simulation analysis results; 4) fitting the deformation curve based on the full-field deformation of the diaphragm under each operating condition and extracting the dimensionless shape factor; 5) constructing a thin-film deformation measurement test bench and measuring the average deformation of a fixed radius region under unknown operating conditions; 6) calculating the calibration coefficient and operating condition coefficient based on the dimensionless shape factor and the average deformation; and 7) solving for the full-field deformation curve of the diaphragm under unknown operating conditions based on the calibration coefficient and operating condition coefficient. This invention can directly reconstruct the full-field deformation from local measurements, addressing an urgent need to overcome the technical bottleneck in this field.

Description

Technical Field

[0001] This invention belongs to the field of thin-film throttling device technology, specifically relating to a method and system for determining the deformation curve of a thin-film throttling device diaphragm. Background Technology

[0002] As a key damping and pressure-stabilizing element in the moving parts of a hydrostatic guide rail, the elastic deformation of the diaphragm under operating pressure difference directly alters the geometry of the throttling gap, leading to significant changes in flow resistance characteristics and ultimately affecting the pressure regulation accuracy and oil film stiffness of the throttling device. Currently, understanding this deformation field mainly relies on three methods: theoretical analysis, computer simulation, and experimental measurement, but all have fundamental limitations. Theoretical analysis is based on highly simplified models, and the calculation results deviate significantly from the actual complex fluid-structure interaction conditions. While computer simulation can make more precise predictions, it is essentially an extrapolation of an idealized digital model and cannot capture the individual differences in real products caused by manufacturing tolerances, material batches, and assembly stresses, nor can it be used for online monitoring of physical products. In terms of experimental measurement, contact methods interfere with the actual deformation state of the tiny diaphragm, while non-contact optical full-field measurements (such as laser interferometers) have high accuracy, but the equipment is expensive, has stringent environmental requirements, and, more importantly, is limited by the compact and enclosed mechanical structure of the throttling device itself, making it difficult to implement effective measurements in industrial settings or under installed conditions.

[0003] These shortcomings collectively lead to a prominent contradiction in the current technological field: on the one hand, there is a severe lack of high-precision, practical real-time measurement methods for diaphragm deformation, resulting in a lack of reliable data for product design verification, production quality control, and in-service equipment condition monitoring; on the other hand, there is currently a lack of simple physical models capable of accurately reconstructing the entire field morphology from a small amount of easily measurable data. Therefore, developing a practical measurement method and system based on fluid-structure interaction that can directly reconstruct the entire field deformation from local measurements has become an urgent need to overcome the technological bottleneck in this field. Summary of the Invention

[0004] This invention provides a method and system for determining the deformation curve of a thin-film throttle diaphragm, with the aim of directly reconstructing the full-field deformation from local measurements, thus addressing an urgent need to overcome the technical bottleneck in this field.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: A method for determining the deformation curve of a thin-film throttle diaphragm includes: 1) Establish a finite element model of the thin-film throttle; 2) Based on the established finite element model of the thin-film throttle, fluid-structure interaction simulation analysis was performed under different operating conditions; 3) Based on the simulation analysis results, extract the full-field deformation of the diaphragm under each working condition; 4) Based on the full-field deformation of the diaphragm under various working conditions, fit the deformation curve and extract the dimensionless shape factor; 5) Set up a thin film deformation measurement test bench and measure the average deformation of a fixed radius area under unknown working conditions; 6) Based on the dimensionless shape factor and average deformation, the calibration coefficient and working condition coefficient are calculated; 7) Based on the calibration coefficient and working condition coefficient, solve for the full-field deformation curve of the diaphragm under unknown working conditions.

[0006] A further improvement of this invention is that, in step 1), the specific process of establishing the finite element model of the thin-film throttle is as follows: Geometric models of the fluid and solid domains were constructed separately using SOLIDWORKS. After being assembled in the assembly according to the actual assembly relationships, they were imported into ANSYS WORKBENCH using the SOLIDWORKS WORKBENCH CAD plugin. ANSYS ICEM was then used to mesh the fluid and solid domains.

[0007] A further improvement of this invention is that, in step 2), the parameter settings for the fluid-structure interaction simulation analysis include: For fluid materials, the density and dynamic viscosity at 25°C are used; for solid materials, the elastic modulus, Poisson's ratio, and density of the diaphragm are used. The fluid domain has its inlet set as a pressure inlet and its outlet set as a pressure outlet, and the contact surface between the diaphragm and the fluid is set as a dynamic mesh interface of the system coupling type; the solid domain applies constant pressure on one side of the pressure stabilizing chamber, the coupling region is set as a fluid-solid interface, and fixed constraints are applied to the edge of the diaphragm. The solution method adopts a transient calculation mode, the flow model is laminar flow, and the convergence residual satisfies the continuity equation and the velocities in the x, y, and z directions are all ≤1e-5.

[0008] A further improvement of the present invention is that, in step 3), based on the simulation analysis results, the full-field deformation of the diaphragm under each working condition is extracted, including: extracting the total deformation data along the diaphragm diameter path through the "Path" function of ANSYS, as the core sample of the full-field deformation data of the diaphragm.

[0009] A further improvement of the present invention is that, in step 4), the deformation curve function... for:

[0010] in, It is a dimensionless shape factor, which is related to the membrane structure and materials; It is a dimensionless deformation trend function, which is determined by a unique dimensionless shape factor. Decision, satisfaction , ; This is the operating condition factor, in units of... With respect to the current operating conditions, i.e., the pressure difference between the inlet and outlet. and initial throttling gap The relevant term represents the magnitude of diaphragm deformation under specified operating conditions.

[0011] A further improvement of this invention is that, in step 5), the constructed thin film deformation measurement test bench includes: a mounting base, a thin film throttle fixed to the mounting base, an eddy current sensor for measuring diaphragm deformation, a locking nut, and a sealing ring. The eddy current sensor is fixed by the locking nut and is positioned opposite to the central region of the diaphragm. The eddy current sensor is a non-contact displacement measurement device. The fixed radius region is the central circular region of the diaphragm, and the dimensionless measurement radius of the eddy current sensor is... for , The actual measurement radius of the sensor. This represents the actual effective radius of the diaphragm.

[0012] A further improvement of this invention is that, in step 6), the calculation formula for the calibration coefficient C is:

[0013] The formula for calculating the operating condition coefficient K is as follows:

[0014] in, It is the average deformation within the central circular area measured by the eddy current sensor.

[0015] A system for determining the deformation curve of a thin-film throttle diaphragm, comprising: Finite element model building unit, to build the finite element model of the thin film throttle; The simulation analysis unit performs fluid-structure interaction simulation analysis under different operating conditions based on the established finite element model of the thin-film throttle. The full-field deformation extraction unit extracts the full-field deformation of the diaphragm under various working conditions based on simulation analysis results; The dimensionless shape factor unit is used to fit the deformation curve and extract the dimensionless shape factor based on the full-field deformation of the diaphragm under various working conditions. The average deformation measurement unit is used to build a thin film deformation measurement test bench and measure the average deformation of a fixed radius area under unknown working conditions. The coefficient calculation unit calculates the calibration coefficient and working condition coefficient based on the dimensionless shape factor and average deformation. The full-field deformation curve solving unit solves the full-field deformation curve of the diaphragm under unknown working conditions based on calibration coefficients and operating condition coefficients.

[0016] A further improvement of this invention lies in the fact that, in the finite element model building unit, the specific process of building the finite element model of the thin-film throttling device is as follows: Geometric models of the fluid and solid domains were constructed separately using SOLIDWORKS. After being assembled in the assembly according to the actual assembly relationships, they were imported into ANSYS WORKBENCH using the SOLIDWORKS WORKBENCH CAD plugin. ANSYS ICEM was then used to mesh the fluid and solid domains.

[0017] A further improvement of this invention is that, in the simulation analysis unit, the parameter settings for the fluid-structure interaction simulation analysis include: For fluid materials, the density and dynamic viscosity at 25°C are used; for solid materials, the elastic modulus, Poisson's ratio, and density of the diaphragm are used. The fluid domain has its inlet set as a pressure inlet and its outlet set as a pressure outlet, and the contact surface between the diaphragm and the fluid is set as a dynamic mesh interface of the system coupling type; the solid domain applies constant pressure on one side of the pressure stabilizing chamber, the coupling region is set as a fluid-solid interface, and fixed constraints are applied to the edge of the diaphragm. The solution method adopts a transient calculation mode, the flow model is laminar flow, and the convergence residual satisfies the continuity equation and the velocities in the x, y, and z directions are all ≤1e-5.

[0018] Compared with the prior art, the present invention has at least the following beneficial technical effects: 1. The characteristic function model constructed based on the fluid-structure interaction simulation results shows extremely high goodness of fit to the simulation data (average R² ≥ 0.95). Due to the core parameters... It has been proven to have excellent stability (variance coefficient CV < 0.5%). The accuracy of this inversion method does not change drastically with the working conditions (pressure difference, initial gap). It can maintain high accuracy and strong robustness under different working conditions, ensuring the reliability and universality of the method.

[0019] 2. This invention is the first to discover and define the "dimensionless shape factor" that determines the deformation morphology of a diaphragm. By revealing the physical law that the shape of the diaphragm deformation curve of a thin-film throttling device is determined solely by the structure itself and is independent of external loads, this study achieves a dimensionality reduction and essential description of complex fluid-structure interaction deformation fields, which has significant original theoretical value.

[0020] 3. This invention simplifies the measurement of full-field deformation, which traditionally relies on expensive and complex optical systems, to a single-point measurement using only a conventional eddy current sensor. Through a mathematical inversion model, it achieves accurate reconstruction from "local average deformation" to "continuous full-field distribution". Attached Figure Description

[0021] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0022] Figure 1 This is a flowchart of the method of the present invention; Figure 2 This is a schematic diagram of the structure of the thin-film throttle deformation measurement system; Figure 3 ANSYS simulation flowchart for thin-film throttles; Figure 4 This is a schematic diagram of the fitting results for a throttling gap of 80 μm; Figure 5 This is a schematic diagram of the fitting results for a throttling gap of 100 μm; Figure 6 This is a schematic diagram of the fitting results for a throttling gap of 120 μm; Figure 7 This is a structural block diagram of the system of the present invention.

[0023] Explanation of reference numerals in the attached figures: 1 is an eddy current sensor; 2 is a locking nut; 3 is a sealing ring; 4 is a throttle end cap; 5 is a diaphragm; 6 is a throttle; 7 is a mounting base. Detailed Implementation

[0024] In the following description, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of the invention. Therefore, the drawings and description are considered to be exemplary in nature and not restrictive.

[0025] In the description of this invention, it should be understood that, as used in this specification and the appended claims, the terms "comprising" and "including" indicate the presence of the described features, integrals, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.

[0026] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0027] It should also be further understood that the term "and / or" as used in this specification and the appended claims refers to any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0028] The accompanying drawings illustrate various structural schematic diagrams according to embodiments disclosed in this invention. These drawings are not to scale, and some details have been enlarged for clarity, and some details may have been omitted. The shapes of the various regions and layers shown in the drawings, as well as their relative sizes and positional relationships, are merely exemplary and may deviate from reality due to manufacturing tolerances or technical limitations. Furthermore, those skilled in the art can design regions / layers with different shapes, sizes, and relative positions as needed.

[0029] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0030] Example 1 This invention provides a method for determining the deformation curve of a thin-film throttle diaphragm, comprising: 1) Establish a finite element model of the thin-film throttle; 2) Based on the established finite element model of the thin-film throttle, fluid-structure interaction simulation analysis was performed under different operating conditions; 3) Based on the simulation analysis results, extract the full-field deformation of the diaphragm under each working condition; 4) Based on the full-field deformation of the diaphragm under various working conditions, fit the deformation curve and extract the dimensionless shape factor; 5) Set up a thin film deformation measurement test bench and measure the average deformation of a fixed radius area under unknown working conditions; 6) Based on the dimensionless shape factor and average deformation, the calibration coefficient and working condition coefficient are calculated; 7) Based on the calibration coefficient and working condition coefficient, solve for the full-field deformation curve of the diaphragm under unknown working conditions.

[0031] In this embodiment, the specific process of establishing the finite element model of the thin-film throttle in step 1) is as follows: Geometric models of the fluid and solid domains were constructed separately using SOLIDWORKS. After being assembled in the assembly according to the actual assembly relationships, they were imported into ANSYS WORKBENCH using the SOLIDWORKS WORKBENCH CAD plugin. ANSYS ICEM was then used to mesh the fluid and solid domains.

[0032] In this embodiment, step 2) includes setting the parameters for the fluid-structure interaction simulation analysis: For fluid materials, the density and dynamic viscosity at 25°C are used; for solid materials, the elastic modulus, Poisson's ratio, and density of the diaphragm are used. The fluid domain has its inlet set as a pressure inlet and its outlet set as a pressure outlet, and the contact surface between the diaphragm and the fluid is set as a dynamic mesh interface of the system coupling type; the solid domain applies constant pressure on one side of the pressure stabilizing chamber, the coupling region is set as a fluid-solid interface, and fixed constraints are applied to the edge of the diaphragm. The solution method adopts a transient calculation mode, the flow model is laminar flow, and the convergence residual satisfies the continuity equation and the velocities in the x, y, and z directions are all ≤1e-5.

[0033] In this embodiment, in step 3), based on the simulation analysis results, the full-field deformation of the diaphragm under each working condition is extracted, including: extracting the total deformation data along the diaphragm diameter path using the "Path" function of ANSYS, as the core sample of the full-field deformation data of the diaphragm.

[0034] In this embodiment, in step 4), the deformation curve function for:

[0035] in, It is a dimensionless shape factor, which is related to the membrane structure and materials; It is a dimensionless deformation trend function, which is determined by a unique dimensionless shape factor. Decision, satisfaction , ; This is the operating condition factor, in units of... With respect to the current operating conditions, i.e., the pressure difference between the inlet and outlet. and initial throttling gap The relevant term represents the magnitude of diaphragm deformation under specified operating conditions.

[0036] In this embodiment, step 5) involves constructing a thin film deformation measurement test bench, which includes: a mounting base, a thin film throttle fixed to the mounting base, an eddy current sensor for measuring diaphragm deformation, a locking nut, and a sealing ring. The eddy current sensor is fixed by the locking nut and is positioned opposite to the central region of the diaphragm. The eddy current sensor is a non-contact displacement measurement device. The fixed radius region is the central circular region of the diaphragm, and the dimensionless measurement radius of the eddy current sensor is... for , The actual measurement radius of the sensor. This represents the actual effective radius of the diaphragm.

[0037] In this embodiment, in step 6), the formula for calculating the calibration coefficient C is:

[0038] The formula for calculating the operating condition coefficient K is as follows:

[0039] in, It is the average deformation within the central circular area measured by the eddy current sensor.

[0040] Example 2 The technical solution of this invention achieves rapid calculation of the overall deformation curve of the thin-film throttling device diaphragm through a three-stage process of "simulation modeling - function construction - measurement calculation," in conjunction with the attached... Figures 1-6 The process is clearly presented. (Attached) Figure 1 This is a flowchart of the method of the present invention. For ease of implementation, the system apparatus configuration for implementing the present invention is defined first, and then the technical process is described in detail: 1. System Configuration The system for implementing the present invention includes: (1) Geometric modeling and simulation system: It consists of SOLIDWORKS (geometric modeling), ANSYS Design Modeler (model preprocessing), ANSYS ICEM (mesh generation), ANSYS FLUENT (fluid calculation), and ANSYS Static Structural (solid deformation calculation); (2) Diaphragm deformation measurement system: single-sided thin-film throttling device, eddy current sensor; corresponding attachments Figure 2 (Throttle body deformation measurement system) 2. Detailed Implementation Steps of the Technical Process Step 1: Geometric Modeling and Mesh Generation (1) Geometric modeling: Open SOLIDWORKS and create the fluid domain and solid domain according to the geometry of the thin-film throttling device. After the fluid domain and solid domain are modeled, they need to be assembled in a new assembly according to the corresponding relationship and saved. After modeling, use the SOLIDWORKS WORKBENCH CAD plugin to directly import the model into ANSYSWORKBENCH. Complete the mesh generation operation of the fluid domain and solid domain in ANSYS.

[0041] Step 2: Setting Simulation Parameters and Boundary Conditions (1) Material parameter settings: ① Fluid material: Set density at 25℃ Dynamic viscosity ; ② Solid materials: Set the elastic modulus Poisson's ratio and density ; (2) Definition of fluid boundary conditions ① Inlet boundary: Set the type to "Pressure Inlet"; ② Outlet boundary: Set the type to "Pressure Outlet"; ③ Fluid-structure interaction surface: Set the contact surface between the diaphragm and the fluid as "Interface" and set it as a moving mesh region, with the type selected as "System Couple".

[0042] (3) Definition of solid boundary conditions: Enable Transient Structural. Suppress the fluid domain, apply constant pressure to one side of the pressure stabilizing chamber, set the coupling region to "Fluid Solid Region", and apply a fixed constraint to the diaphragm.

[0043] (4) Solver parameter settings: Select “Transient” in FLUENT, select “SIMPLEC” as the solver, select “Laminar” as the flow model, and set the convergence residuals as follows: continuity ≤ 1e-5, x-velocity ≤ 1e-5, y-velocity ≤ 1e-5, z-velocity ≤ 1e-5.

[0044] Step 3: ANSYS Fluid-Structure Interaction Simulation Calculation and Post-Processing (1) Calculation execution: In FLUENT, initialize the flow field using "Standard Initialization"; open "System Couple", set the corresponding time step and number of time steps, and then start the coupling calculation.

[0045] (2) Data Preprocessing: After calculation, the deformation data is extracted using the "Path" function: Define the path along the membrane diameter, export the "Total Deformation" data along the path, and obtain the deformation data along the membrane diameter. (See attached image) Figure 3 This is the ANSYS simulation process for thin-film throttles.

[0046] Step 4: Construction of the logic function and derivation of the diaphragm deformation curve This step is the core of the invention, and includes two parts: establishing the diaphragm deformation formula and establishing the "measurement-inversion" model.

[0047] (1) First, perform dimensionless processing of the physical quantities. Define the characteristic length. Let be the effective radius of the diaphragm, and let be the radius of the fixed edge of the diaphragm. Therefore .

[0048] Define dimensionless radius Obviously And at the edge .

[0049] Define the dimensionless measurement radius of the eddy current sensor as: ,in .

[0050] (2) Through systematic mathematical fitting analysis of a large amount of simulation data (deformation fields under different pressure differences and different initial throttling gaps), this invention has made a key discovery: all deformation curves can be described with high precision by a unified function containing only two parameters: (1) in, The dimensionless shape factor is only related to the membrane structure and material; the whole within the brackets... It is a dimensionless deformation trend function, which is determined by a unique dimensionless shape factor. Decision, satisfaction , .

[0051] This is the operating condition factor, in units of... Only related to the current operating conditions (inlet and outlet pressure difference) and initial throttling gap It is related to the diaphragm deformation amplitude under the set operating conditions.

[0052] For a membrane with a specific structure (determined material, thickness, and radius), the dimensionless shape factor... It is a constant. Whether it's pressure difference... Did the pressure change (0.2MPa, 0.4MPa, 0.6MPa, 0.8MPa), or did the initial throttling gap change (80)? 100 120 A series of fitting results Its coefficient of variation (CV) is extremely small. This indicates that the dimensionless shape factor... Its performance is determined solely by its inherent structure and is independent of external loads and throttling clearances. (See attached diagram.) Figure 4 5, 6 (Fitting results of diaphragm deformation curves under different throttling gaps) (2) Calculate the full-field deformation curve based on the single-point measurement value of the sensor. This measurement system uses a measurement radius of... The eddy current sensor measures the average deformation within the central circular region. .

[0053] This average value is the integral average of the characteristic function over the measurement region: (2) Will Substituting into the above equation, we get ... (3) In the above formula Defined as calibration coefficients, which are only related to the dimensionless shape factor. Dimensionless measurement radius of the sensor and feature length The relevant constants. Their values ​​can be obtained analytically: (4) Therefore, the working condition coefficient K is: (5) After prior calibration of the known dimensionless shape factor And calculate the calibration coefficients Under the premise that the average deformation is measured on site, it is only necessary to measure the deformation. The operating condition coefficient K under the current operating condition can then be solved using the above formula. Connect K with... Substituting into equation (1), the full-field deformation curve under the current working condition can be obtained. .

[0054] (3) Measurement and calculation of diaphragm deformation curve under unknown working conditions Following the fluid-structure interaction method described in step 1, simulation data under a certain working condition is obtained, and the dimensionless shape factor of this diaphragm is extracted. .

[0055] According to the appendix Figure 1 The measurement system shown is equipped with an eddy current sensor or similar measuring device, or measures the average deformation within a specific area. .

[0056] Calculate the calibration coefficients according to formulas (4) and (5). and operating condition coefficient .

[0057] The overall diaphragm deformation curve under unknown operating conditions can be calculated using formula (1). When the operating conditions change, the eddy current sensor or similar measuring device only needs to perform one measurement to obtain the average value of the diaphragm deformation in the measurement area, and then the overall diaphragm deformation curve under the new operating conditions can be calculated using the above steps.

[0058]

[0059] (4) Explanation of boundary conditions and model verification The dimensionless characteristic function model used in this invention is at the fixed edge of the diaphragm ( At point ), the geometric constraint condition that the deformation is zero is strictly satisfied. For an ideal fixed boundary, the required rotation angle is 0 (i.e., the slope). The mechanical conditions of ) are explained by the model as follows:

[0060] Its value is not zero. This mathematical characteristic is a reasonable trade-off between the chosen function form and the model's simplicity. The following points require further explanation: For the typical structural parameters of the present invention ( The absolute value of the boundary slope calculated using the above formula is approximately The slope is extremely small relative to the diaphragm diameter of 23 mm, which is consistent with engineering practice.

[0061] Furthermore, this invention aims to invert the deformation field of the diaphragm body region through local measurement of the central region. Sensor measurement area ( Far from the boundary, both theoretical analysis and simulation verification show that the influence of the aforementioned small slope condition differences at the boundary is limited to a very small range at the edge, affecting the measurement area and the main deformation zone. The morphological influence of the model is a high-order small quantity and can be completely ignored. The model has been fully verified in simulations and fully meets the accuracy and reliability requirements of engineering applications.

[0062] Example 3 like Figure 7 As shown, the present invention provides a system for determining the deformation curve of a thin-film throttle diaphragm, comprising: Finite element model building unit, to build the finite element model of the thin film throttle; The simulation analysis unit performs fluid-structure interaction simulation analysis under different operating conditions based on the established finite element model of the thin-film throttle. The full-field deformation extraction unit extracts the full-field deformation of the diaphragm under various working conditions based on simulation analysis results; The dimensionless shape factor unit is used to fit the deformation curve and extract the dimensionless shape factor based on the full-field deformation of the diaphragm under various working conditions. The average deformation measurement unit is used to build a thin film deformation measurement test bench and measure the average deformation of a fixed radius area under unknown working conditions. The coefficient calculation unit calculates the calibration coefficient and working condition coefficient based on the dimensionless shape factor and average deformation. The full-field deformation curve solving unit solves the full-field deformation curve of the diaphragm under unknown working conditions based on calibration coefficients and operating condition coefficients.

[0063] In the finite element model building unit of this embodiment, the specific process of building the finite element model of the thin-film throttle is as follows: Geometric models of the fluid and solid domains were constructed separately using SOLIDWORKS. After being assembled in the assembly according to the actual assembly relationships, they were imported into ANSYS WORKBENCH using the SOLIDWORKS WORKBENCH CAD plugin. ANSYS ICEM was then used to mesh the fluid and solid domains.

[0064] In the simulation analysis unit of this embodiment, the parameter settings for the fluid-structure interaction simulation analysis include: For fluid materials, the density and dynamic viscosity at 25°C are used; for solid materials, the elastic modulus, Poisson's ratio, and density of the diaphragm are used. The fluid domain has its inlet set as a pressure inlet and its outlet set as a pressure outlet, and the contact surface between the diaphragm and the fluid is set as a dynamic mesh interface of the system coupling type; the solid domain applies constant pressure on one side of the pressure stabilizing chamber, the coupling region is set as a fluid-solid interface, and fixed constraints are applied to the edge of the diaphragm. The solution method adopts a transient calculation mode, the flow model is laminar flow, and the convergence residual satisfies the continuity equation and the velocities in the x, y, and z directions are all ≤1e-5.

[0065] The inventive points protected by this invention are as follows: 1. A method for inverting the full-field deformation of a thin-film throttling device diaphragm, comprising: pre-obtaining a dimensionless shape factor that is only related to the diaphragm structure (…). ); Measure the average deformation of a predetermined local area on the diaphragm; Based on the dimensionless shape factor ( The average deformation is used to calculate the full-field deformation distribution of the diaphragm using a predetermined inversion algorithm. 2. A thin-film throttle diaphragm full-field deformation inversion system includes: a non-contact eddy current sensor or similar displacement measuring device for measuring the average deformation of a local area of ​​the diaphragm; and a signal processing unit connected to the sensor.

[0066] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the scope of the invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0067] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can be appropriately combined to form other embodiments that can be understood by those skilled in the art. The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made based on the technical concept proposed in this invention shall fall within the scope of protection of the claims of this invention.

Claims

1. A method for determining the deformation curve of a thin-film throttle diaphragm, characterized in that, include: 1) Establish a finite element model of the thin-film throttle; 2) Based on the established finite element model of the thin-film throttle, fluid-structure interaction simulation analysis was performed under different operating conditions; 3) Based on the simulation analysis results, extract the full-field deformation of the diaphragm under each working condition; 4) Based on the full-field deformation of the diaphragm under various working conditions, fit the deformation curve and extract the dimensionless shape factor; 5) Set up a thin film deformation measurement test bench and measure the average deformation of a fixed radius area under unknown working conditions; 6) Based on the dimensionless shape factor and average deformation, the calibration coefficient and working condition coefficient are calculated; 7) Based on the calibration coefficient and working condition coefficient, solve for the full-field deformation curve of the diaphragm under unknown working conditions.

2. The method for determining the diaphragm deformation curve of a thin-film throttle device according to claim 1, characterized in that, In step 1), the specific process of establishing the finite element model of the thin-film throttle is as follows: Geometric models of the fluid and solid domains were constructed separately using SOLIDWORKS. After being assembled in the assembly according to the actual assembly relationships, they were imported into ANSYS WORKBENCH using the SOLIDWORKS WORKBENCH CAD plugin. ANSYS ICEM was then used to mesh the fluid and solid domains.

3. The method for determining the diaphragm deformation curve of a thin-film throttle device according to claim 1, characterized in that, In step 2), the parameter settings for the fluid-structure interaction simulation analysis include: For fluid materials, the density and dynamic viscosity at 25°C are used; for solid materials, the elastic modulus, Poisson's ratio, and density of the diaphragm are used. The fluid domain has its inlet set as a pressure inlet and its outlet set as a pressure outlet, and the contact surface between the diaphragm and the fluid is set as a dynamic mesh interface of the system coupling type; the solid domain applies constant pressure on one side of the pressure stabilizing chamber, the coupling region is set as a fluid-solid interface, and fixed constraints are applied to the edge of the diaphragm. The solution method adopts a transient calculation mode, the flow model is laminar flow, and the convergence residual satisfies the continuity equation and the velocities in the x, y, and z directions are all ≤1e-5.

4. The method for determining the diaphragm deformation curve of a thin-film throttle according to claim 1, characterized in that, In step 3), based on the simulation analysis results, the full-field deformation of the diaphragm under each working condition is extracted, including: extracting the total deformation data along the diaphragm diameter path using the "Path" function of ANSYS, which serves as the core sample of the full-field deformation data of the diaphragm.

5. The method for determining the diaphragm deformation curve of a thin-film throttle according to claim 1, characterized in that, In step 4), the deformation curve function for: in, It is a dimensionless shape factor, which is related to the membrane structure and materials; It is a dimensionless deformation trend function, which is determined by a unique dimensionless shape factor. Decision, satisfaction , ; This is the operating condition factor, in units of... With respect to the current operating conditions, i.e., the pressure difference between the inlet and outlet. and initial throttling gap The relevant term represents the magnitude of diaphragm deformation under specified operating conditions.

6. The method for determining the diaphragm deformation curve of a thin-film throttle according to claim 5, characterized in that, In step 5), the constructed thin film deformation measurement test bench includes: a mounting base, a thin film throttle fixed to the mounting base, an eddy current sensor for measuring diaphragm deformation, a locking nut, and a sealing ring. The eddy current sensor is fixed by the locking nut and is positioned opposite to the central region of the diaphragm. The eddy current sensor is a non-contact displacement measurement device. The fixed radius region is the central circular region of the diaphragm. The dimensionless measurement radius of the eddy current sensor... for , The actual measurement radius of the sensor. This represents the actual effective radius of the diaphragm.

7. The method for determining the diaphragm deformation curve of a thin-film throttle device according to claim 6, characterized in that, In step 6), the formula for calculating the calibration coefficient C is: The formula for calculating the operating condition coefficient K is as follows: in, It is the average deformation within the central circular area measured by the eddy current sensor.

8. A system for determining the deformation curve of a thin-film throttle diaphragm, characterized in that, include: Finite element model building unit, to build the finite element model of the thin film throttle; The simulation analysis unit performs fluid-structure interaction simulation analysis under different operating conditions based on the established finite element model of the thin-film throttle. The full-field deformation extraction unit extracts the full-field deformation of the diaphragm under various working conditions based on simulation analysis results; The dimensionless shape factor unit is used to fit the deformation curve and extract the dimensionless shape factor based on the full-field deformation of the diaphragm under various working conditions. The average deformation measurement unit is used to build a thin film deformation measurement test bench and measure the average deformation of a fixed radius area under unknown working conditions. The coefficient calculation unit calculates the calibration coefficient and working condition coefficient based on the dimensionless shape factor and average deformation. The full-field deformation curve solving unit solves the full-field deformation curve of the diaphragm under unknown working conditions based on calibration coefficients and operating condition coefficients.

9. A system for determining the diaphragm deformation curve of a thin-film throttle device according to claim 8, characterized in that, The specific process for establishing the finite element model of the thin-film throttle device in the finite element model building unit is as follows: Geometric models of the fluid and solid domains were constructed separately using SOLIDWORKS. After being assembled in the assembly according to the actual assembly relationships, they were imported into ANSYS WORKBENCH using the SOLIDWORKS WORKBENCH CAD plugin. ANSYS ICEM was then used to mesh the fluid and solid domains.

10. A system for determining the diaphragm deformation curve of a thin-film throttle valve according to claim 8, characterized in that, In the simulation analysis unit, the parameter settings for the fluid-structure interaction simulation analysis include: For fluid materials, the density and dynamic viscosity at 25°C are used; for solid materials, the elastic modulus, Poisson's ratio, and density of the diaphragm are used. The fluid domain has its inlet set as a pressure inlet and its outlet set as a pressure outlet, and the contact surface between the diaphragm and the fluid is set as a dynamic mesh interface of the system coupling type; the solid domain applies constant pressure on one side of the pressure stabilizing chamber, the coupling region is set as a fluid-solid interface, and fixed constraints are applied to the edge of the diaphragm. The solution method adopts a transient calculation mode, the flow model is laminar flow, and the convergence residual satisfies the continuity equation and the velocities in the x, y, and z directions are all ≤1e-5.

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