Spiral groove gas film sealing steady-state parameter optimization method based on flow field analysis

Abstract

The invention discloses a spiral groove gas film sealing steady-state parameter optimization method based on flow field analysis, and the method comprises the steps: building a three-dimensional model of a spiral groove gas film and a sealing ring through three-dimensional modeling software, and carrying out the grid division of the three-dimensional model; setting a gas film steady-state parameter calculation formula and a thermal steady-state energy calculation formula in simulation software, and performing simulation analysis; determining gas film steady-state parameters of the sealing ring according to a simulation result, such as gas film opening force, leakage rate, gas film rigidity and rigidity-to-leakage ratio, so as to explore the sealing performance of the sealing assembly and the direction of subsequent parameter optimization; and finally determining the parameters of the actually processed sealing ring. Through an analogue simulation mode, the redundant workload of a gas film sealing experiment can be effectively reduced, the experiment period is greatly shortened, efficient and accurate technical support is provided for design, parameter optimization and subsequent experiments of spiral groove gas film sealing, and the method has remarkable engineering application value.

Description

Technical Field

[0001] This invention belongs to the technical field of air film sealing flow field simulation methods, specifically involving a method for optimizing steady-state parameters of spiral groove air film seals based on flow field analysis. Background Technology

[0002] Gas film sealing is a non-contact mechanical seal technology that uses gas as the sealing medium. It achieves a gas seal on the rotating shaft end face by forming a stable gas film through the hydrodynamic pressure effect generated by micro-grooves on the sealing end face. The working process of spiral groove gas film sealing varies with the equipment speed and can be divided into three stages. The core logic is that the hydrodynamic pressure effect generates an opening force, and the gas film enters a stable state after balancing the closing force. When the equipment is not running, the preload of the elastic element pushes the stationary ring and the rotating ring into contact, resulting in a tight seal between the sealing end faces. The wear-resistant coating prepared on the end face provides protection during the dry contact stage at start-up and shutdown. When the shaft drives the rotating ring to rotate, the spiral groove on the rotating ring end face generates a pumping effect. Gas is captured from the low-pressure side of the sealing ring by the spiral surface of the groove and flows towards the high-pressure side along the spiral direction of the groove. Due to the sealing dam within the spiral groove, the gas volume is compressed as it flows within the groove. When the opening force generated by the increased pressure exceeds the closing force, the stationary ring is lifted, and the rotating and stationary rings separate, generating a uniform gas film with a thickness of 1~10μm. At this point, the seal enters a non-contact state. This sealing ring has become a key component in equipment such as compressors and turbines in the petrochemical, energy, and aerospace industries.

[0003] Air film sealing experiments require frequent changes to multiple parameters to comprehensively explore the influence of different conditions on sealing performance. The parameters that need adjustment in the experiment cover two core dimensions: first, the spiral groove structure parameters, such as groove depth (5~20μm), groove width ratio (30~70%), lead (5~20mm), and groove angle (tested degree by degree from 30° to 60°); second, the operating condition parameters, including air film thickness, medium pressure, and rotational speed. Each time a set of parameters is changed, the test specimen must be reassembled, and the pressure sensor and torque measuring instrument calibrated to ensure stable and consistent experimental conditions. The time required for each parameter adjustment and preparation is considerable.

[0004] In summary, the fabrication and testing of spiral groove air film sealing kits presents significant challenges: the manufacturing process is complex, environmental requirements are stringent, and the process is not only difficult but also time-consuming and expensive in terms of materials. Furthermore, conducting spiral groove parameter optimization experiments requires substantial investment of manpower and resources, resulting in significant overall costs. Summary of the Invention

[0005] The purpose of this invention is to provide an experimental method for optimizing steady-state parameters of spiral groove air film seal based on flow field analysis. By calculating the steady-state parameters of the sealing spiral groove and ensuring the accuracy of the air film seal experiment, this invention solves the problem of large experimental workload and long cycle caused by the frequent replacement of multiple parameters in the air film seal experiment in the prior art. It clarifies the direction of parameter optimization for subsequent experiments and supports parameter improvement according to target performance requirements.

[0006] The technical solution adopted in this invention is an experimental method for optimizing steady-state parameters of spiral groove air film sealing based on flow field analysis, which includes the following steps: Step 1: Create 3D models of the dynamic and static rings and the air film that conform to the actual dimensions using 3D modeling software, and assemble them. Import the assembly of the air film and the dynamic and static rings into the finite element analysis software and set the boundary conditions of the air film (the dynamic and static ring models in the assembly are suppressed).

[0007] Step 2: Import the 3D model file of the air film with boundary conditions set in Step 1 into the mesh generation software to generate the mesh and obtain the air film mesh model. Step 3: Import the air film mesh model obtained in Step 2 into the flow field simulation software to solve the air film flow field. The fluid calculation method is set to laminar flow model calculation, and the continuity equation, momentum equation, energy equation, and SIMPLEC algorithm are used. The temperature distribution and pressure distribution of the air film, i.e., the air film flow field data, are obtained by adjusting the inlet and outlet pressure and rotation speed. The steady-state parameters of the air film that measure the sealing performance, namely leakage, air film opening force, air film stiffness, and stiffness-leakage ratio, are also solved. Step 4: In the thermodynamics module of the finite element simulation software, set the boundary conditions for the dynamic and static rings and the coupling surface between the dynamic and static rings and the air film (unsuppress the suppression of the dynamic and static ring models in the assembly, and suppress the air film). Share the air film flow field data obtained in Step 3 to the corresponding coupling surface, then divide the dynamic and static ring mesh, and set the relevant solid heat transfer parameters, namely the initial temperature, the heat flux on the coupling surface between the dynamic ring and the air film, and the convective heat transfer coefficient on the coupling surface between the static ring and the air film. Finally, perform thermodynamic calculations to obtain the temperature field distribution of the dynamic and static rings.

[0008] Step 5: In the statics module of the finite element simulation software, set the boundary conditions of the dynamic and static rings and the coupling surface between the dynamic and static rings and the air film. Share the calculation results of the thermodynamics module obtained in Step 4 and the air film flow field data obtained in Step 3 to the statics module to perform thermo-fluid-structure interaction calculations. The calculations use solid conservation equations, solid energy transfer equations, dynamic ring heat conduction equations, static ring heat conduction equations, and fluid-structure interaction control equations. Finally, analyze the stress, strain, and deformation of the dynamic and static rings. Step 6: Post-process the results, that is, for the gas film pressure cloud map generated in Step 3 and the stress-strain cloud map and deformation cloud map of the dynamic and static rings generated in Step 4, adjust the spatial display perspective of the cloud map, and extract cross-sectional cloud maps of different axial interfaces to clearly present the distribution pattern and gradient change characteristics of the gas film pressure in different areas of the sealing end face and the changes of the sealing ring deformation and stress-strain. Step 7: Optimize the spiral groove parameters based on the simulation results. By analyzing the gas film steady-state data after simulation convergence, clarify the influence of changes in a single spiral groove parameter on the gas film steady-state characteristics, and then determine the optimal value range of the parameter to optimize the overall performance of the spiral groove and prepare sufficient data analysis for subsequent experiments.

[0009] The invention is further characterized in that, In step two, the mesh generation method is adopted to construct auxiliary points and auxiliary lines for the model and to generate a mesh for the air film model.

[0010] The formula for calculating the air film opening force is as follows:

[0011] in F 0 represents the opening force, in N; p It is the pressure exerted by the air film on a certain point on the sealing end face, in Pa; R 0、 R i These are the inner and outer diameters of the end face, respectively, in mm; θ To solve for the angle of the region; N g Represents the number of repetitions in the circumferential direction; R It is the radial coordinate vector in the polar coordinate system, that is, the radial distance from a certain point on the air film sealing end face to the sealing center; The formula for calculating leakage is as follows:

[0012] θ To solve for the angle of the region; δ The thickness of the air film is μm; Q This is the leakage amount, kg·s -1 ; v r Let be the radial velocity component of the fluid in polar coordinates, in m / s; The formula for calculating air film stiffness is as follows:

[0013] in, K The gas film stiffness is expressed in N·μm. -1 ; δ The thickness of the air film is μm; F0 represents the air film opening force, in N; The formula for calculating the rigid-leakage ratio is as follows:

[0014] in, For the leakage ratio, N·s·kg -1 ·μm -1 .

[0015] In step three, the fluid calculation method in the flow field simulation software is set to laminar flow model calculation, using the continuity equation, momentum equation, energy equation, and SIMPLEC algorithm, and the solution is obtained by adjusting the inlet and outlet pressure and rotation speed.

[0016] In step four, the relevant parameters for solid heat transfer include initial temperature, heat flux, and convective heat transfer coefficient.

[0017] Solid heat transfer parameters include fixed temperature, initial temperature value, convective heat transfer coefficient, and heat flux boundary conditions.

[0018] In step five, the calculation of thermal-fluid-structure interaction adopts the solid conservation equation, solid energy transfer equation, dynamic ring heat conduction equation, static ring heat conduction equation, and fluid-structure interaction control equation.

[0019] The conservation equations for solids are as follows:

[0020] in, Density of solid; For Cauchy stress tensor; This is the local acceleration vector in the solid domain; It is a volume force vector.

[0021] The energy transfer equation in the solid region is:

[0022] 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; Explicit enthalpy, representing the explicit enthalpy of a solid, that is, the heat energy carried by a unit mass of solid; The thermal conductivity of a solid is W / (m·K). It could be a potential heat source inside the solid. For the temperature gradient, its modulus is the rate of temperature change in that direction.

[0023] The heat conduction equation for the moving ring is shown below:

[0024] In the formula: k sr The value is the thermal conductivity of the moving ring, W / (m·K); ρ r Dynamic ring density, kg / m 3 ; c r Specific heat capacity of the moving ring, J / (kg·K); v sx The component of the velocity of the moving ring in the x-direction, m / s; v sy The component velocity of the moving ring in the y direction is m / s; T r Let K be the temperature of the moving ring.

[0025] The heat conduction equation for the stationary ring is shown below:

[0026] In the formula: k ss Where is the static thermal conductivity, W / (m·K); T s , where K is the stationary temperature.

[0027] The fluid-structure interaction governing equations are as follows:

[0028] In the formula: subscript f For fluid; subscript s It is a solid; q Heat flow; T For temperature; τ f Forces acting on fluids; τ s For solid stress; Z For displacement. n This represents the unit normal vector of the fluid-solid interface, which is perpendicular to the fluid-solid contact interface.

[0029] The beneficial effects of this invention are: Simultaneously, the simulation modeling of the spiral groove film flow field and the spiral groove film sealing ring is included. Firstly, simulation analysis can be used to analyze a designed but unmanufactured sealing ring model, obtaining its film flow field calculation data and analyzing opening force, leakage, film stiffness, and stiffness-to-leakage ratio. After thermo-fluid-structure interaction calculations, the influence of stress and strain on the sealing ring is investigated. Secondly, the sealing ring parameters can be optimized by changing the groove shape, groove depth, spiral angle, and inclination within the sealing groove, reducing the workload of subsequent experiments. Attached Figure Description

[0030] Figure 1 This is a simulation workflow diagram in an embodiment of the present invention; Figure 2 This is a two-dimensional geometric model of the spiral groove air film seal in the embodiments of the present invention; Figure 3 This is the spiral groove 1 / Ng air film model in the embodiment of the present invention; Figure 4 This refers to the block region defined by the spiral groove 1 / Ng air film in this embodiment of the invention; Figure 5 It is the integral mesh of the spiral groove air film in the embodiment of the present invention; Figure 6 This is a spiral groove air film pressure cloud diagram under ideal parameters in an embodiment of the present invention; Figure 7 This is a spiral groove air film temperature cloud diagram under ideal parameters in an embodiment of the present invention; Figure 8 This is a diagram of the spiral groove seal annular variation in an embodiment of the present invention; Figure 9 This describes the influence of changing a single parameter on the steady-state characteristics of the gas film in this embodiment of the invention. Detailed Implementation

[0031] The technical solution of the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0032] Example 1 The steady-state parameter optimization method for spiral groove air film seal based on flow field analysis of the present invention is as follows: Figure 1 As shown, please follow these steps: Step 1: Create 3D models of the dynamic and static rings and the air film that conform to the actual dimensions using 3D modeling software, and assemble them. Import the assembly of the air film and the dynamic and static rings into the finite element analysis software and set the boundary conditions of the air film (the dynamic and static ring models in the assembly are suppressed).

[0033] Step 2: Import the 3D model file of the air film with boundary conditions set in Step 1 into the mesh generation software to generate the mesh and obtain the air film mesh model. Step 3: Import the air film mesh model obtained in Step 2 into the flow field simulation software to solve the air film flow field. The fluid calculation method is set to laminar flow model calculation, and the continuity equation, momentum equation, energy equation, and SIMPLEC algorithm are used. The temperature distribution and pressure distribution of the air film, i.e., the air film flow field data, are obtained by adjusting the inlet and outlet pressure and rotation speed. The steady-state parameters of the air film that measure the sealing performance, namely leakage, air film opening force, air film stiffness, and stiffness-leakage ratio, are also solved. Step 4: In the thermodynamics module of the finite element simulation software, set the boundary conditions for the dynamic and static rings and the coupling surface between the dynamic and static rings and the air film (unsuppress the suppression of the dynamic and static ring models in the assembly, and suppress the air film). Share the air film flow field data obtained in Step 3 to the corresponding coupling surface, then divide the dynamic and static ring mesh, and set the relevant solid heat transfer parameters, namely the initial temperature, the heat flux on the coupling surface between the dynamic ring and the air film, and the convective heat transfer coefficient on the coupling surface between the static ring and the air film. Finally, perform thermodynamic calculations to obtain the temperature field distribution of the dynamic and static rings.

[0034] Step 5: In the statics module of the finite element simulation software, set the boundary conditions of the dynamic and static rings and the coupling surface between the dynamic and static rings and the air film. Share the calculation results of the thermodynamics module obtained in Step 4 and the air film flow field data obtained in Step 3 to the statics module to perform thermo-fluid-structure interaction calculations. The calculations use solid conservation equations, solid energy transfer equations, dynamic ring heat conduction equations, static ring heat conduction equations, and fluid-structure interaction control equations. Finally, analyze the stress, strain, and deformation of the dynamic and static rings. Step 6: Post-process the results, that is, for the gas film pressure cloud map generated in Step 3 and the stress-strain cloud map and deformation cloud map of the dynamic and static rings generated in Step 4, adjust the spatial display perspective of the cloud map, and extract cross-sectional cloud maps of different axial interfaces to clearly present the distribution pattern and gradient change characteristics of the gas film pressure in different areas of the sealing end face and the changes of the sealing ring deformation and stress-strain. Step 7: Optimize the spiral groove parameters based on the simulation results. By analyzing the gas film steady-state data after simulation convergence, clarify the influence of changes in a single spiral groove parameter on the gas film steady-state characteristics, and then determine the optimal value range of the parameter to optimize the overall performance of the spiral groove and prepare sufficient data analysis for subsequent experiments.

[0035] Example 2 Based on Example 1, the three-dimensional models of the sealing ring and air film in step one are further established in SOLIDWORKS, such as... Figure 2 As shown. Due to the very thin thickness of the air film and the presence of a number of large-angle edges in the model, the mesh quality is relatively low. Therefore, the thickness was increased by a factor of 1000 during model adjustment, as shown. Figure 3 As shown. In the Geometry module of WORKBENCH, set the gas film boundary conditions: Pressure-inlet, Pressure-outlet, Perodic-1, Perodic-2, Moving-Wall, Stationary-Wall, which are pressure inlet, pressure outlet, periodic boundary 1, periodic boundary 2, rotating wall, and stationary wall.

[0036] The outer radius of the air-supported membrane simulation model is 25mm, the inner radius is 12.5mm, the inner radius of the groove area is 17.5mm, the thickness is 6mm, the helix angle is 20°, and the helix formula is as follows:

[0037] in r The reference radius is in mm; t These are parameter variables used to describe the angle changes during the parameterization construction process of the helix; α ρ is the helix angle in degrees; pi is the mathematical constant π, used here to convert the helix angle from degrees to radians; exp is the natural exponential function, used to express the helix as a function of parameters. t Variational spiral radial expansion.

[0038] Example 3 Building upon Example 2, in step two, the final 3D model generated in step one is imported into ICEM CFD. A block-based meshing method is used to construct auxiliary points and lines for the model, dividing the air-supported membrane model into 20 regions. Each region has 38 vertices, corresponding one-to-one with 38 points on the air-supported membrane model. Figure 4 As shown. After setting the mapping relationship, the periodic boundary and the number of grid nodes are set, with 588,900 grid nodes and a total grid size of 667,716. The number of nodes for the film thickness is set to 5. This setting results in sealing performance, such as opening force and leakage, being minimally affected by the grid change rate, leading to relatively stable results. The number of nodes along the film thickness direction is 5-20, and the number of nodes along the radial direction is 10-20-40, generating a structured grid dominated by hexahedrons. The array function is used to array the 1 / Ng grid into a complete film mesh, as shown. Figure 5 As shown. The mesh quality was checked, and the result was 0.869–0.998, meeting the required quality accuracy. The mesh .msh file was exported.

[0039] Example 4 Building upon Example 3, further in step three, the air film flow field analysis based on finite element simulation software involves first importing the air film mesh model into Fluent for scaling and restoring the original dimensions for calculation. A laminar flow calculation model is used, with the energy equations enabled. Both the inlet and outlet pressures are set to 1.01 × 10 MPa, and the rotor rotation speed is set to 2 × 10⁻⁶. 4 r / min. The pressure-velocity coupling scheme is SIMPLEC, a semi-implicit method of the pressure coupling equation, and the initialization scheme is standard initialization. After the calculation, the film flow field data and steady-state film parameters are obtained. The leakage rate is 6.26423 × 10⁻⁶. -5(kg / s), the air film opening force is 1719.17N.

[0040] Example 5 Building upon Example 4, further in step four, based on the analysis of the steady-state thermal module in WORKBENCH, after setting the boundary conditions for the dynamic and static rings and the coupling surface, the dynamic and static ring meshes are divided, and the coupling surface mesh is refined. Solid heat transfer parameters are set, with the initial temperature set to 650℃ and the heat flux on the coupling surface between the dynamic ring and the air film set to 1×10⁻⁶. 5 W / m 2 The convective heat transfer coefficient at the coupling surface between the stationary ring and the air film is 30 W / (m²). 2 (·K), and finally the calculations were performed. The distribution of the temperature field in the moving and stationary rings was obtained.

[0041] Furthermore, in step five, after linking the static structure module, the distribution of the dynamic and static ring temperature fields obtained from the steady-state thermal module and the air film flow field data obtained from FLUENT are coupled and analyzed. After performing thermal-fluid-structure coupling analysis, the deformation and stress-strain of the sealing ring are obtained.

[0042] Furthermore, the results obtained in step six are post-processed. Specifically, the gas film pressure cloud map generated in step three and the stress-strain and deformation cloud maps of the dynamic and static rings generated in step four are post-processed. By adjusting the spatial display perspective of the cloud maps, cross-sectional cloud maps of different axial interfaces are captured, clearly showing the distribution pattern and gradient variation characteristics of the gas film pressure in different regions of the sealing end face, as well as the changes in the deformation and stress-strain of the sealing ring. By observing the cloud map conditions, the influence of rotor rotation speed and helical groove parameters on the steady-state parameters of the gas film is investigated, such as... Figure 6 , Figure 7 , Figure 8 As shown; Example 6 Building upon Example 5, step seven further optimizes the spiral groove parameters based on simulation results. By analyzing the gas film steady-state data after simulation convergence, the influence of changes in a single spiral groove parameter on the gas film steady-state characteristics is clarified, thereby determining the optimal value range of this parameter. This optimizes the overall performance of the spiral groove and provides sufficient data analysis for subsequent experiments. Figure 9 As shown.

[0043] The steady-state performance parameters of the air film include air film opening force, leakage, air film stiffness, and stiffness-to-leakage ratio.

[0044] The formula for calculating the air film opening force is as follows:

[0045] in F 0 represents the opening force, in N; pIt is the pressure exerted by the air film on a certain point on the sealing end face, in Pa; R 0、 R i These are the inner and outer diameters of the end face, respectively, in mm; θ To solve for the angle of the region; N g Represents the number of repetitions in the circumferential direction; R It is the radial coordinate vector in the polar coordinate system, that is, the radial distance from a certain point on the air film sealing end face to the sealing center; The formula for calculating leakage is as follows:

[0046] θ To solve for the angle of the region; δ The thickness of the air film is μm; Q This is the leakage amount, kg·s -1 ; v r Let be the radial velocity component of the fluid in polar coordinates, in m / s; The formula for calculating air film stiffness is as follows:

[0047] in, K The gas film stiffness is expressed in N·μm. -1 ; δ The thickness of the air film is μm; F 0 represents the air film opening force, in N; The formula for calculating the rigid-leakage ratio is as follows:

[0048] in, For the leakage ratio, N·s·kg -1 ·μm -1 .

[0049] Solid heat transfer parameters include fixed temperature, initial temperature value, and heat flux boundary conditions.

[0050] The conservation equations for solids are as follows:

[0051] in, Density of solid; For Cauchy stress tensor; This is the local acceleration vector in the solid domain; It is a volume force vector.

[0052] The energy transfer equation in the solid region is:

[0053] 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; Explicit enthalpy, representing the explicit enthalpy of a solid, that is, the heat energy carried by a unit mass of solid; The thermal conductivity of a solid is W / (m·K). It could be a potential heat source inside the solid. For the temperature gradient, its modulus is the rate of temperature change in that direction.

[0054] The heat conduction equation of the moving ring is shown below:

[0055] In the formula: k sr The value is the thermal conductivity of the moving ring, W / (m·K); ρ r Dynamic ring density, kg / m 3 ; c r Specific heat capacity of the moving ring, J / (kg·K); v sx The velocity component of the moving ring in the x-direction, m / s; v sy The component velocity of the moving ring in the y direction is m / s; T r Let K be the temperature of the moving ring.

[0056] The heat conduction equation for the stationary ring is shown below:

[0057] In the formula: k ss Where is the static thermal conductivity, W / (m·K); T s , where K is the stationary temperature.

[0058] The fluid-structure interaction governing equations are as follows:

[0059] In the formula: subscript f For fluid; subscript s It is a solid; q Heat flow; T For temperature; τ f Forces acting on fluids; τ s For solid stress; Z For displacement. nThis represents the unit normal vector of the fluid-solid interface, which is perpendicular to the fluid-solid contact interface.

Claims

1. A method for optimizing steady-state parameters of spiral groove air film seal based on flow field analysis, characterized in that, The steps are as follows: Step 1: Create a 3D model of the dynamic and static rings and the air film using 3D modeling software, assemble them, and then import them into the finite element analysis software to set the boundary conditions of the air film. Step 2: Import the results from Step 1 into the mesh generation software to generate the mesh and obtain the air film mesh model; Step 3: Import the air film mesh model into the flow field simulation software to solve the air film flow field, obtain the temperature distribution and pressure distribution of the air film, i.e., the air film flow field data, and solve the air film steady-state parameters that measure the sealing performance, including leakage, air film opening force, air film stiffness, and stiffness-leakage ratio. Step 4: In the thermodynamic module of the finite element simulation software, set the boundary conditions of the dynamic and static rings and the coupling surface between the dynamic and static rings and the gas film, share the gas film flow field data to the corresponding coupling surface, divide the dynamic and static ring mesh, set the solid heat transfer related parameters, perform thermodynamic calculations, and obtain the temperature field distribution of the dynamic and static rings. Step 5: In the statics module of the finite element simulation software, set the boundary conditions of the dynamic and static rings and the coupling surface between the dynamic and static rings and the air film. Share the results of the thermodynamic calculation in Step 4 and the air film flow field data to the statics module to perform thermo-fluid-solid coupling calculations. Finally, analyze the stress, strain and deformation of the dynamic and static rings. Step 6: Post-process the results, that is, for the gas film pressure cloud map generated in Step 3 and the stress-strain cloud map and deformation cloud map of the dynamic and static rings generated in Step 4, adjust the spatial display perspective of the cloud map, and extract cross-sectional cloud maps of different axial interfaces to present the distribution pattern and gradient change characteristics of the gas film pressure in different areas of the sealing end face and the changes of the sealing ring deformation and stress-strain. Step 7: Optimize the spiral groove parameters based on the simulation results. By analyzing the gas film steady-state data after simulation convergence, clarify the influence of changes in a single spiral groove parameter on the gas film steady-state characteristics, and determine the optimal value range of the parameter.

2. The method for optimizing steady-state parameters of a spiral groove air film seal based on flow field analysis according to claim 1, characterized in that, In step two, the meshing is performed by using a block-based meshing method to construct auxiliary points and auxiliary lines for the model, thereby dividing the air film model into a mesh.

3. The method for optimizing steady-state parameters of a spiral groove air film seal based on flow field analysis according to claim 1, characterized in that, The formula for calculating the air film opening force is as follows: in F 0 represents the opening force, in N; p It is the pressure exerted by the air film on a certain point on the sealing end face, in Pa; R 0、 R i These are the inner and outer diameters of the end face, respectively, in mm; θ To solve for the angle of the region; N g Represents the number of repetitions in the circumferential direction; R It is the radial coordinate vector in the polar coordinate system, that is, the radial distance from a certain point on the air film sealing end face to the sealing center; The formula for calculating the leakage amount is as follows: θ To solve for the angle of the region; δ The thickness of the air film is μm; Q This is the leakage amount, kg·s -1 ; v r Let be the radial velocity component of the fluid in polar coordinates, in m / s; The formula for calculating the air film stiffness is as follows: in, K The gas film stiffness is expressed in N·μm. -1 ; δ The thickness of the air film is μm; F 0 represents the opening force, in N; The formula for calculating the stiffness-to-leakage ratio is as follows: in, For the leakage ratio, N·s·kg -1 ·μm -1 .

4. The method for optimizing steady-state parameters of a spiral groove air film seal based on flow field analysis according to claim 1, characterized in that, In step three, the fluid calculation method in the flow field simulation software is set to laminar flow model calculation, using the continuity equation, momentum equation, energy equation, and SIMPLEC algorithm, and the solution is obtained by adjusting the inlet and outlet pressure and rotation speed.

5. The method for optimizing steady-state parameters of spiral groove air film seal based on flow field analysis according to claim 1, characterized in that, In step four, the solid heat transfer related parameters include initial temperature, heat flux, and convective heat transfer coefficient.

6. The method for optimizing steady-state parameters of a spiral groove air film seal based on flow field analysis according to claim 1, characterized in that, In step five, the calculation of the heat-fluid-structure interaction adopts the solid conservation equation, the solid region energy transfer equation, the dynamic ring heat conduction equation, the static ring heat conduction equation, and the fluid-structure interaction control equation.

7. The method for optimizing steady-state parameters of a spiral groove air film seal based on flow field analysis according to claim 6, characterized in that, The solid conservation equation is as follows: in, Density of solid; For Cauchy stress tensor; This is the local acceleration vector in the solid domain; It is a volume force vector.

8. The method for optimizing steady-state parameters of a spiral groove air film seal based on flow field analysis according to claim 6, characterized in that, The energy transfer equation in the solid region is: In this equation, the left side represents the convective energy transfer caused by the motion of the solid; the right side represents the heat flow caused by heat conduction and possible heat sources inside the solid. The absolute velocity vector of the solid; Explicit enthalpy, representing the explicit enthalpy of a solid, that is, the heat energy carried by a unit mass of solid; The thermal conductivity of a solid is W / (m·K); It could be a potential heat source inside the solid. For the temperature gradient, its modulus is the rate of temperature change in that direction.

9. The method for optimizing steady-state parameters of a spiral groove air film seal based on flow field analysis according to claim 6, characterized in that, The dynamic ring heat conduction equation is as follows: In the formula: k sr The value is the thermal conductivity of the moving ring, W / (m·K); ρ r Dynamic ring density, kg / m 3 ; c r Specific heat capacity of the moving ring, J / (kg·K); v sx The component of the velocity of the moving ring in the x-direction, m / s; v sy The component velocity of the moving ring in the y direction is m / s; T r Let K be the temperature of the moving ring. The heat conduction equation for the stationary ring is as follows: In the formula: k ss Where is the static thermal conductivity, W / (m·K); T s , where K is the stationary temperature.

10. The method for optimizing steady-state parameters of a spiral groove air film seal based on flow field analysis according to claim 6, characterized in that, The fluid-structure interaction control equations are as follows: In the formula: subscript f It is a fluid; Subscript s It is a solid; q Heat flow; T For temperature; τ f Forces acting on fluids; τ s For solid stress; Z For displacement, n This represents the unit normal vector of the fluid-solid interface, which is perpendicular to the fluid-solid contact interface.

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