Brush type sealing flow-solid-heat-grinding multi-physics field efficient coupling method

Abstract

The invention discloses a brush type sealing fluid-solid-heat-grinding multi-physics field efficient coupling method, and particularly relates to the field of aero-engine sealing. Comprising the following steps: establishing an interdigitated tube bundle solid model, taking the interdigitated tube bundle solid model as a first model, and executing a division step; cFD simulation is carried out on the first model after grid division, and flow field distribution is obtained; determining a three-dimensional aerodynamic load of the brush wires based on the flow field distribution; determining the three-dimensional pneumatic deformation result of the brush wires according to the three-dimensional pneumatic load, and determining the wear volume of each brush wire; according to the pneumatic deformation result of the brush wires and the abrasion volume of each brush wire, the forked row tube bundle solid model is updated, and a deformation geometric model under aerodynamic force is obtained; and taking the deformation geometric model as a first model, starting to execute a division step, and stopping iteration until a brush wire three-dimensional pneumatic deformation result reaches a first condition, so as to finish accurate simulation of a fluid-solid-heat-grinding coupling effect.

Description

Technical Field

[0001] This application relates to the field of aero-engine sealing, and in particular to a method for efficient coupling of multiple physical fields of flow-solid-thermal-wearing in brush seals. Background Technology

[0002] As aero-engines / gas turbines evolve towards higher thrust-to-weight ratios, higher cycle temperatures, and longer lifespans, the sealing performance of critical components such as high-pressure turbines and compressor interstages has become a bottleneck for overall system efficiency and safe lifespan. Brush seals, with their flexible bristles that adapt to deformation and exhibit low leakage, have become the preferred alternative to traditional labyrinth seals. However, in real-world service environments, the operating conditions of brush seal systems are highly complex: the deformation of the bristles under high-temperature, high-pressure aerodynamic loads reconstructs the internal flow channel structure of the bristle bundle in real time. This geometric deformation continuously feeds back into the flow field distribution through a fluid-structure interaction mechanism. Simultaneously, the heat generated by the friction between the bristles and the rotor causes localized temperature rises and material softening, while the rotor's thermal expansion exacerbates material wear, further leading to changes in the sealing gap. These fluid-structure-thermal-wear multi-physics interactions form a closed-loop feedback loop, continuously affecting the sealing performance and service life of brush seals. Traditional single-physics analysis methods struggle to accurately predict the trajectory of sealing performance degradation and its internal dynamic behavior, while traditional strongly coupled calculation methods suffer from difficulties in convergence and long computation times. Summary of the Invention

[0003] The main objective of this application is to provide a highly efficient multi-physics coupling method for brush seal flow-solid-thermal-wearing, which aims to solve the problem that existing methods cannot accurately predict the degradation trajectory of seal performance while maintaining low computational cost.

[0004] To achieve the above objectives, this application provides a high-efficiency coupling method for multiphysics fields of fluid-solid-thermal-grinding in brush-type sealing, comprising: establishing a solid model of a forked tube bundle, the solid model including baffles, brush filament bundles, and a fluid domain; determining the contact normal pressure between the brush filaments and the rotor based on the parameters of the solid model of the forked tube bundle, and using the contact normal pressure between the brush filaments and the rotor as the first contact normal pressure; wherein, the parameters include the interference between the brush filaments and the rotor; using the solid model of the forked tube bundle as the first model, performing a meshing step; the meshing step is to perform meshing on the first model to obtain a meshed first model; determining the frictional heat flux density of the contact bottom surface between the brush filaments and the rotor based on the first contact normal pressure, heat flow distribution coefficient, friction coefficient, rotor surface linear velocity, and the area of ​​the contact bottom surface between the brush filaments and the rotor; using the frictional heat flux density of the contact bottom surface between the brush filaments and the rotor as boundary conditions, and performing meshing on the meshed first model. CFD simulation was performed to obtain static pressure. Based on the static pressure, the three-dimensional aerodynamic load of the deformed brush bristles was determined, and the contact normal pressure between the brush bristles and the rotor was re-determined according to the three-dimensional aerodynamic load of the deformed brush bristles. The three-dimensional aerodynamic deformation result of the brush bristles was determined according to the elastic modulus of the brush bristles and the three-dimensional aerodynamic load. The wear volume of each brush bristle was determined according to the wear coefficient between the brush bristles and the rotor, the re-determined contact normal pressure between the brush bristles and the rotor, the rotor surface linear velocity, the wear time, and the hardness of the brush bristles. Based on the aerodynamic deformation result of the brush bristles and the wear volume of each brush bristle, the solid model of the cross-tube bundle was updated to obtain the deformable geometric model under aerodynamic force. The deformable geometric model was used as the first model, and the re-determined contact normal pressure between the brush bristles and the rotor was used as the first contact normal pressure. The partitioning step was started until the three-dimensional aerodynamic deformation result of the brush bristles reached the first condition, at which point the iteration stopped, and the fluid-solid-thermal-wear coupling was completed.

[0005] Optionally, the first model is meshed, including: dividing the brush filament bundle region into several subdomains along the radial direction of the brush filaments, meshing each subdomain to obtain a mesh model for each subdomain; mapping and splicing the nodes or elements of adjacent contact surfaces in the mesh models of all subdomains to obtain the first model after meshing; wherein, the brush filament bundle region includes a fluid domain and a brush filament solid domain.

[0006] Optionally, the contact normal pressure between the brush bristles and the rotor is determined based on the parameters of the cross-branch tube bundle solid model, including: determining the contact normal pressure between the brush bristles and the rotor based on the interference between the brush bristles and the rotor, the elastic modulus, diameter, length, and installation tilt angle of the brush bristles, as well as the aerodynamic component of the brush bristles in the radial direction of the rotor and the first preset relationship.

[0007] Optionally, the frictional heat flux density of the brush bristles and the bottom surface of the rotor is determined based on the first contact normal pressure, heat flow distribution coefficient, friction coefficient, rotor surface linear velocity, and the area of ​​the brush bristles contacting the rotor bottom surface. This includes determining the frictional heat flux density of the brush bristles and the bottom surface of the rotor contacting the rotor by taking the quotient of the product of the first contact normal pressure, heat flow distribution coefficient, friction coefficient, rotor surface linear velocity, and heat flow distribution coefficient, and the area of ​​the brush bristles contacting the rotor bottom surface.

[0008] Optionally, the three-dimensional aerodynamic load includes the aerodynamic force components of the brush filament in the circumferential, axial and radial directions of the rotor; the three-dimensional aerodynamic load of the deformed brush filament is determined based on the static pressure, including: determining the aerodynamic force components of the brush filament in each direction of the rotor according to the component of the static pressure in the corresponding direction and the length of the brush filament, so as to obtain the three-dimensional aerodynamic load of the brush filament.

[0009] Optionally, the three-dimensional aerodynamic deformation result includes the three-dimensional aerodynamic deformation amount and the position after deformation; the three-dimensional aerodynamic deformation result of the brush bristles is determined based on the elastic modulus of the brush bristles and the three-dimensional aerodynamic load; the three-dimensional aerodynamic load is used as a boundary condition, and the three-dimensional aerodynamic deformation amount of the brush bristles is determined based on the elastic modulus of the brush bristles, the length of the brush bristles, and the installation tilt angle of the brush bristles; the position of the brush bristles after deformation is determined based on the sum of the three-dimensional aerodynamic deformation amount of the brush bristles and the initial position of the brush bristles.

[0010] Optionally, based on the aerodynamic deformation results of the brush bristles and the wear volume of each brush bristle, the solid model of the cross-branch tube bundle is updated to obtain a deformable geometric model under aerodynamic conditions. This includes: generating the deformed solid domains of each row of brush bristles based on the aerodynamic deformation results of the brush bristles and the wear volume of each brush bristle; establishing an envelope with the deformed brush bristles as the skeleton, and removing the brush bristle solid domains and baffle solid domains using Boolean operations to obtain the deformed fluid domains; and updating the cross-branch tube bundle solid model using the deformed fluid domains and the solid domains of each row of brush bristles to obtain a deformable geometric model under aerodynamic conditions.

[0011] Optionally, the first condition is that the three-dimensional aerodynamic deformation is less than 0.2% of the brush filament diameter.

[0012] Optionally, after determining the wear volume of each bristle, the method further includes determining that the wear of the current bristle ends when the wear volume of any bristle reaches a preset volume; and determining that the wear of the bristle bundle ends when the wear volume of each row of bristles in the bristle bundle reaches a preset volume.

[0013] To achieve the above objectives, this application also provides a brush-type sealing fluid-solid-thermal-grinding multiphysics field high-efficiency coupling device, comprising: a model building module for building a solid model of a forked tube bundle, the solid model of the forked tube bundle including baffles, brush filament bundles and a fluid domain; determining the parameters of the contact normal pressure between the brush filaments and the rotor based on the solid model of the forked tube bundle, and taking the contact normal pressure between the brush filaments and the rotor as the first contact normal pressure; wherein, the parameters include the interference between the brush filaments and the rotor; a meshing module for using the solid model of the forked tube bundle as the first model and performing a meshing step; the meshing step is to perform meshing on the first model to obtain the meshed first model; a simulation module for determining the frictional heat flux density of the contact surface between the brush filaments and the rotor based on the first contact normal pressure, friction coefficient, rotor surface linear velocity and the area of ​​the contact surface between the brush filaments and the rotor; using the frictional heat flux density of the contact surface between the brush filaments and the rotor as boundary conditions, performing CFD simulation on the meshed first model to obtain the static pressure; and a pneumatic load. The module is divided into four parts: a load determination module, a deformation result determination module, and a model update module. The former is used to determine the three-dimensional aerodynamic load of the deformed brush bristles based on the static pressure, and to redetermine the contact normal pressure between the brush bristles and the rotor based on the three-dimensional aerodynamic load of the deformed brush bristles. The latter is used to determine the three-dimensional aerodynamic deformation result of the brush bristles based on the elastic modulus of the brush bristles and the three-dimensional aerodynamic load. The latter is used to determine the wear volume of each brush bristle based on the wear coefficient between the brush bristles and the rotor, the redetermined contact normal pressure between the brush bristles and the rotor, the rotor surface linear velocity, the wear time, and the hardness of the brush bristles. The former is used to update the solid model of the cross-tube bundle based on the aerodynamic deformation result of the brush bristles and the wear volume of each brush bristle, and to obtain the deformed geometric model under aerodynamic force. The latter is used to start the partitioning step with the deformed geometric model as the first model and the redetermined contact normal pressure between the brush bristles and the rotor as the first contact normal pressure, and to stop the iteration until the three-dimensional aerodynamic deformation result of the brush bristles reaches the first condition, thus completing the coupling of fluid-solid-thermal-wear.

[0014] Compared with the prior art, the beneficial effects of this application are as follows: The present invention provides a high-efficiency multi-physics coupling method for brush seals, which involves establishing a solid model of a forked tube bundle, setting the frictional heat flux density at the contact surface between the brush filaments and the rotor, and performing CFD numerical simulation on the solid model to achieve coupled solution of the fluid and thermal fields. Based on the flow field distribution, the three-dimensional aerodynamic load on the brush filaments is determined, and the contact normal pressure between the deformed brush filaments and the rotor, as well as the deformation results, are calculated to determine the deformation geometry of the brush filaments under aerodynamic forces, thus rapidly realizing the information mapping and transmission between the fluid and solid fields. Based on the contact normal pressure between the deformed brush filaments and the rotor, the wear volume of each row of brush filaments is determined, and the solid model of the forked tube bundle is updated based on the wear volume and deformation results, completing bidirectional data feedback between the fluid, solid, thermal, and wear fields. This achieves accurate simulation of the fluid-solid-thermal-wear coupling effect of the brush seal. In each CFD simulation, the frictional heat flux density between the brush filaments and the rotor is revised using the heat flow distribution coefficient. The nonlinear correction factor is calculated by the interference between the brush filaments and the rotor, as well as the length and angle of the brush filaments, to correct the interference between the brush filaments and the rotor, thereby accurately solving the contact normal pressure between the brush filaments and the rotor. At the same time, the material hardness is corrected, thereby correcting the wear formula. It can efficiently and accurately reflect the real three-dimensional deformation, heat transfer and wear process of multiple rows of brush filaments under the operating conditions of the brush seal, that is, the internal dynamic behavior of the brush seal system, thereby obtaining reliable thermal flow field information and structural information, which helps to improve the accuracy of predicting the seal life. Without relying on complex experimental procedures, a single-cycle cross-tube bundle solid model is established. Through multi-physics coupled numerical simulation, the sealing performance under different design and operating conditions can be quickly evaluated. After each iteration, the model is updated, and CFD simulation calculations are performed using the updated model, which can reduce the computation time and enable the model to converge quickly. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the efficient coupling method of multiple physics fields of flow-solid-thermal-grinding for brush sealing in this application; Figure 2 This is a schematic diagram of the solid model of the cross-tube bundle in the efficient coupling method of multiphysics fields of brush seal flow-solid-thermal-grinding in this application; Figure 3 A schematic diagram of the structure of a single-cycle cross-branch tube bundle solid model established for the embodiments of this application; Figure 4 for Figure 3 Enlarged view of point B in the middle; Figure 5 This is a schematic diagram of mesh division in an embodiment of this application; Figure 6 for Figure 5 Enlarged view of point A in the middle; Figure 7 This is a diagram showing the deformation results of the brush bristle centerline in the axial-radial section according to an embodiment of this application; Figure 8 This is a schematic diagram of the fluid-solid-thermal-abrasion coupling deformation mesh at the tips of each row of brush filaments in an embodiment of this application.

[0016] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0018] Understandably, brush seal systems are a high-performance dynamic sealing technology used in rotating machinery (such as gas turbines, steam turbines, aero engines, and centrifugal compressors). The core of this technology is to achieve a low-leakage seal for gas / liquid media through the flexible contact between the "dense elastic brush filament bundle" and the rotor.

[0019] The first embodiment of the present invention provides a method for efficient coupling of multiple physical fields of flow-solid-thermal-grinding in brush-type sealing, such as... Figure 1 As shown, the specific steps include: Step S1, establish a solid model of the cross-shaped tube bundle, such as Figure 2 As shown, the solid model of the cross-branch tube bundle includes baffles, brush bundle 3, and fluid domain; Understandably, the baffles include a front baffle 1 and a rear baffle 2, located on either side of the bristle bundle 3 composed of multiple bristles 31. Pressure enters from the front baffle side and exits from the rear baffle side. The geometric tolerance during model building is maintained at 10. -6 Within m, ensure zero-error connection between the subsequent mesh and the physical field. The three-dimensional aerodynamic load of the brush filament 31 is the aerodynamic force component of the brush filament 31 in the circumferential, axial and radial directions of the rotor 4. Taking the aerodynamic force component of the brush filament 31 in the circumferential direction of the rotor 4 as an example, it will be referred to as the aerodynamic force component of the brush filament 31 in the circumferential direction below.

[0020] Step S2: Based on the parameters of the cross-tube bundle solid model, determine the contact normal pressure between the brush 31 and the rotor 4, and take the contact normal pressure between the brush 31 and the rotor 4 as the first contact normal pressure; wherein, the parameters include the interference between the brush 31 and the rotor. Specifically, the parameters also include the elastic modulus, diameter, length, and installation angle of the brush bristles 31. Based on the interference between the brush bristles 31 and the rotor 4, and the elastic modulus, diameter, length, and installation angle of the brush bristles 31, as well as the aerodynamic component of the brush bristles 31 in the radial direction and a first preset relationship, the contact normal pressure between the brush bristles 31 and the rotor 4 is determined. The first preset relationship is as follows: (1); In the formula, F n The contact force between the brush bristles 31 and the rotor 4. This represents the interference between the brush filament 31 and the rotor 4. dThe diameter of the bristles is 31. L The bristles are 31mm long. Let 31 be the aerodynamic component acting radially on the brush bristles in the initial state. =0, The installation tilt angle of bristle 31, E The elastic modulus of bristle 31, I It is the moment of inertia; In this embodiment, the nonlinear correction factor is: The nonlinear correction factor is calculated by the interference between the brush filament 31 and the rotor 4, the length and angle of the brush filament 31, and the interference between the brush filament 31 and the rotor 4 is corrected, thereby accurately solving the contact normal pressure between the brush filament 31 and the rotor 4.

[0021] Step S3: Using the cross-shaped tube bundle solid model as the first model, perform the meshing step; the meshing step is to mesh the first model. Specifically, the brush filament bundle 3 region is divided into several sub-domains along the radial direction of the brush filaments 31. Each sub-domain is meshed using a hexahedral structure to obtain a mesh model for each sub-domain. For the nodes or elements of adjacent contact surfaces in the mesh models of all sub-domains, they are mapped and spliced ​​one-to-one through interface or coupling boundaries to obtain the first model after meshing. The brush filament bundle 3 region includes the solid domain of the brush filaments 31 and the fluid domain between the individual brush filaments 31. During the splicing process, the total number of nodes is compressed to save computational resources while ensuring accuracy.

[0022] Step S4: Determine the frictional heat flux density of the contact surface between the brush bristles 31 and the rotor 4 based on the first contact normal pressure, heat flow distribution coefficient, friction coefficient, surface linear velocity of rotor 4 and the area of ​​the contact surface between the brush bristles 31 and rotor 4. Specifically, the frictional heat flux density of the contact surface between the brush bristles 31 and the rotor 4 is determined by dividing the product of the first contact normal force, heat flow distribution coefficient, friction coefficient, and the surface linear velocity of rotor 4 by the heat flow distribution coefficient, and the area of ​​the contact surface between the brush bristles 31 and rotor 4. q The calculation formula is as follows: (2); In the formula, The heat flow distribution coefficient represents the proportion of frictional heat flow transmitted to the brush bristles 31. The coefficient of friction between the brush bristles 31 and the rotor 4 is given. A The contact area between the brush bristles 31 and the rotor 4 is the bottom surface area. The brush bristles 31 are often made of Haynes 25 high-temperature alloy. The rotor 4 is often coated with chromium carbide to suppress shaft wear. Actual measurements show that the friction coefficient between the two is between 0.23 and 0.35. v The linear velocity of rotor surface 4; (3); In the formula, The thermal conductivity of brush bristles 31 is... The thermal conductivity of rotor 4 is... The bristle density is 31. The coating density of rotor 4, The specific heat capacity at constant pressure for brush bristles 31. The specific heat capacity at constant pressure of the coating of rotor 4; (4); In the formula, D The diameter of rotor 4, n Rotor speed 4; (5); By transforming formula (2) according to formulas (3)-(5), we obtain the final formula for the frictional heat flux density of the contact surface between the brush bristles 31 and the rotor 4: (6); Step S5: Using the frictional heat flux density of the contact surface between the brush filament 31 and the rotor 4 as the boundary condition, perform CFD simulation on the first model after mesh generation to obtain the static pressure. Specifically, boundary conditions are set, including the total inlet pressure and temperature, the static pressure and temperature at the outlet, and the frictional heat flux density at the contact bottom surface between the brush 31 and the rotor 4. Based on the total inlet temperature, the thermal conductivity and specific heat capacity of the baffle at the corresponding temperature are set. Considering the characteristics of the baffle changing with temperature, CFD simulation is performed on the first model after meshing to obtain the static pressure, specifically the components of the static pressure in the circumferential, axial, and radial directions. In single-valued simulations, when the residuals of the continuity equation, energy equation, and turbulence equation are all reduced to 10... -5 Furthermore, if the monitored parameters (pressure, velocity, flow rate) remain constant, the flow-heat exchange field coupling calculation is considered to have converged.

[0023] In this embodiment, during each CFD simulation, the frictional heat flux density between the brush filament 31 and the rotor 4 is revised using the heat flow distribution coefficient, and the contact normal pressure between the brush filament 31 and the rotor 4 is determined using the interference between the brush filament 31 and the rotor 4. This allows for the correction of the wear volume formula, enabling efficient simulation and solution of the heat transfer and wear process of the multi-row brush filament 31 under operating conditions and reflecting its true three-dimensional deformation, i.e., reflecting the internal dynamic behavior of the brush seal system, and thus predicting the wear life of the multi-row brush filament 31 with high accuracy.

[0024] Step S6: Determine the three-dimensional aerodynamic load of the deformed brush bristles 31 based on the static pressure, and redetermine the contact normal pressure between the brush bristles 31 and the rotor 4 based on the three-dimensional aerodynamic load of the deformed brush bristles 31. Specifically, based on the three-dimensional vector analysis method, according to the components of static pressure in the corresponding directions and the length of brush bristles 31, the aerodynamic components of brush bristles 31 in each direction are determined, and the three-dimensional aerodynamic load of the deformed brush bristles 31 is obtained, the expression of which is as follows: (7); In the formula, , , These represent the aerodynamic components experienced by the deformed brush bristles 31 in the circumferential, axial, and radial directions, respectively. , , These represent the components of static pressure in the circumferential, axial, and radial directions, respectively. L The bristles are 31mm long.

[0025] Step S7: Determine the three-dimensional aerodynamic deformation result of the brush bristles 31 based on the elastic modulus of the brush bristles 31 and the three-dimensional aerodynamic load; wherein, the three-dimensional aerodynamic deformation result includes the amount of three-dimensional aerodynamic deformation and the position after deformation; Specifically, based on the nonlinear beam bending theory, the three-dimensional aerodynamic load is used as the boundary condition. The three-dimensional aerodynamic deformation of the brush bristles 31 is determined according to the elastic modulus, the length of the brush bristles 31, and the installation angle of the brush bristles 31. The position of the brush bristles 31 after deformation is determined by the sum of the three-dimensional aerodynamic deformation and the initial position of the brush bristles 31, expressed as: (8); In the formula, , , This indicates the position of bristle 31 after deformation. x 0、 y 0、 z 0 represents the initial position of brush bristles 31. , , These represent the deformation of the brush bristles 31 in the circumferential, axial, and radial directions, respectively. F cx , F cy 、F cz The components of the contact force between brush bristles 31 in the circumferential, axial, and radial directions of the rotor 4 are given. F px , F py 、F pzThe components of the contact force between the rear baffle and the brush bristles 31 in the circumferential, axial, and radial directions of the rotor 4 are given. The contact force is determined by the real-time contact state between brush bristles 31 and between brush bristles 31 and the baffle, and is obtained by iterative solution using a line-to-line Hertzian contact model and the theory of elastic foundation beams. The corresponding frictional force can be solved using Coulomb's law of friction. To fit the correction function; Step S8: Based on the wear coefficient between the brush bristles 31 and the rotor 4, the redefined contact normal force between the brush bristles 31 and the rotor 4, the surface linear velocity of the rotor 4, the wear time, and the hardness of the brush bristles 31, determine the wear volume of each brush bristle 31; the formula for calculating the wear volume is as follows: (9); In the formula, K ad The wear coefficients of brush filament 31 and rotor 4 are given. According to experimental results, the wear of brush filament 31 is mainly adhesive wear, and its measured coefficient ranges from 10. -9 -10 -5 between; F n The contact force between the brush bristles 31 and the rotor 4. t i For bristle wear time 31, K fat The fatigue wear coefficient, for N The fatigue index under cyclic loading; H represents the hardness of brush bristles 31. The calculation needs to consider the influence of the temperature distribution at the tip of brush bristles 31. The expression is: (10); In the formula, H0 is the material hardness at room temperature. k This is an empirical coefficient representing the change in material hardness with temperature. T 0 represents the room temperature value. For example, experimental data for Haynes 25 alloy shows that the specific hardness range is 405MPa to 722MPa within the temperature range of 25℃ to 760℃.

[0026] In this embodiment, nonlinear beam bending theory is adopted to comprehensively analyze the various forces on the brush bristles at one time (including the three-dimensional aerodynamic load of airflow on the brush bristles 31, the contact force and friction force (fatigue wear coefficient) between the brush bristles 31, the contact normal pressure and friction force (wear coefficient) between the brush bristles 31 and the rotor 4, and the contact force and friction force between the brush bristles and the rear baffle), so as to achieve a fully coupled analysis of the brush bristle deformation and obtain the real-time results of the aerodynamic deformation of the brush bristles, which can further improve the accuracy of the simulation of the performance degradation of the sealing system.

[0027] Step S9: Based on the aerodynamic deformation results of the brush bristles 31 and the wear volume of each brush bristle 31, update the solid model of the cross-branch tube bundle to obtain the deformation geometric model under aerodynamic force. Specifically, based on the aerodynamic deformation results of the brush filaments 31 and the wear volume of each brush filament 31, the solid domains of each row of brush filaments 31 after deformation are generated. The brush filament bundle 3 includes multiple rows, each row consisting of multiple brush filaments 31. The solid domains of each row of brush filaments 31 after deformation are generated based on the position and wear volume of each row of brush filaments 31 after deformation. An envelope is established using the deformed brush filaments 31 as the skeleton, and Boolean operations are used to remove the solid domains of the brush filaments 31 and the baffle solid domains to obtain the deformed fluid domains. The fluid domains and the solid domains of each row of brush filaments 31 are used to update the fluid domains and solid domains of the brush filaments 31 in the cross-tube bundle solid model to obtain the deformed geometric model under aerodynamic forces.

[0028] Step S10: Using the deformed geometric model as the first model and the newly determined contact normal pressure between the brush filament 31 and the rotor 4 as the first contact normal pressure, the meshing step begins, i.e., returning to step S3 to mesh the first model until the three-dimensional aerodynamic deformation result of the brush filament 31 meets the first condition, at which point the iteration stops, completing the fluid-solid-thermal-grind coupling. The first condition is that the three-dimensional aerodynamic deformation is less than 0.2% of the diameter of the brush filament 31.

[0029] In this embodiment, a single-cycle cross-tube bundle solid model is established without relying on a complex experimental process. Through multiphysics coupled numerical simulation, the sealing performance under different design and operating conditions can be quickly evaluated. After each iteration, the model is updated, and CFD simulation calculations are performed using the updated model, which can reduce the computation time.

[0030] Furthermore, the coupling method of this invention can also track the entire wear process. Specifically, based on the Archard wear theory, it determines whether the wear between the brush bristle 31 and the rotor 4 has ended according to the wear volume of each brush bristle 31, thus achieving full-process tracking of wear. The method for determining whether wear has ended is as follows: when the wear volume of any brush bristle 31 reaches a preset volume, the wear of the current brush bristle 31 is determined to have ended, and the wear termination time of that brush bristle 31 is locked and recorded as _____. The wear of the brush filament bundle 3 ends when the wear volume of each row of brush filaments 31 in the brush filament bundle 3 reaches the preset volume. This criterion requires only one scalar comparison to achieve high-precision tracking of the entire wear process. The preset volume is calculated based on the preset interference between the brush filaments 31 and the rotor 4.

[0031] A second embodiment of the present invention provides a brush-type sealing fluid-solid-thermal-grinding multi-physics field high-efficiency coupling device, comprising: The model building module is used to build a solid model of the cross-branch tube bundle, which includes baffles, brush bundle 3, and fluid domain. Based on the parameters of the cross-branch tube bundle solid model, the contact normal pressure between brush 31 and rotor 4 is determined, and the contact normal pressure between brush 31 and rotor 4 is taken as the first contact normal pressure. The parameters include the interference between brush 31 and rotor 4. The partitioning module is used to take the cross-shaped tube bundle solid model as the first model and perform the partitioning step; the partitioning step is to perform meshing on the first model to obtain the meshed first model. The simulation module is used to determine the frictional heat flux density of the contact surface between the brush 31 and the rotor 4 based on the first contact normal pressure, heat flow distribution coefficient, friction coefficient, surface linear velocity of rotor 4, and the area of ​​the contact surface between the brush 31 and the rotor 4; and to perform CFD simulation on the first model after meshing using the frictional heat flux density of the contact surface between the brush 31 and the rotor 4 as boundary conditions to obtain the static pressure. The aerodynamic load determination module is used to determine the three-dimensional aerodynamic load of the deformed brush bristles 31 based on the static pressure, and to re-determine the contact normal pressure between the brush bristles 31 and the rotor 4 based on the three-dimensional aerodynamic load of the deformed brush bristles 31. The deformation result determination module is used to determine the three-dimensional aerodynamic deformation result of the brush bristles 31 based on the elastic modulus and three-dimensional aerodynamic load of the brush bristles 31. The wear volume determination module is used to determine the wear volume of each brush bristle 31 based on the wear coefficient between the brush bristle 31 and the rotor 4, the redefined contact normal pressure between the brush bristle 31 and the rotor 4, the surface linear velocity of the rotor 4, the wear time, and the hardness of the brush bristle 31. The model update module is used to update the solid model of the cross-tube bundle based on the aerodynamic deformation results of the brush filament 31 and the wear volume of each brush filament 31, so as to obtain the deformation geometry model under aerodynamic force. The iteration module is used to take the deformed geometric model as the first model and the redefined contact normal pressure between the brush filament 31 and the rotor 4 as the first contact normal pressure to start the division step until the three-dimensional aerodynamic deformation result of the brush filament 31 reaches the first condition, then the iteration stops and the coupling of fluid-solid-thermal-grinding is completed.

[0032] Example Step S100: In this embodiment, to improve computational efficiency, a single-row minimum cycle period model is established, such as... Figure 3-4 The interference between brush filament 31 and rotor 4 in the model = 0.1mm; First, divide the model into several subdomains in the radial direction, and then uniformly mesh the fluid domain and solid domain using a hexahedral structure, such as Figure 5-6 After setting the frictional heat flux density of the contact surface between the brush filament 31 and the rotor 4, the CFD numerical simulation begins.

[0033] Step S110: Process the CFD numerical simulation results to obtain the static pressure and extract the three-dimensional aerodynamic load for each brush filament 31; use the three-dimensional aerodynamic load as boundary conditions to calculate the deformation of the brush filament 31 and the position of the deformed brush filament 31. The deformation results of the brush filament 31 are as follows: Figure 7 The axial deformation of the tip of the first row of brush bristles (31) is 4.8 × 10⁻⁶. -5 m, the axial deformation of the tip of the last row of brush bristles 31 is 9.78×10 m. -6 m. This indicates that the multi-field coupling model established in this embodiment can accurately capture the micro-deformation behavior of the brush filament 31 under the combined action of aerodynamic force, thermal load, and contact force, providing a reliable basis for predicting the sealing gap.

[0034] Step S120: In this embodiment, the brush bristles 31 are made of Haynes 25 high-temperature alloy, and CrMoV steel is selected as the material for the rotor 4. Therefore, the coefficient of friction between the brush bristles 31 and the rotor 4 is... The heat distribution index is 0.3. The value is 0.5; the adhesive wear coefficient Kad is 10. -5 The fatigue wear effect is ignored; based on the average temperature of the tip of the brush bristle 31, the hardness H is determined to be 550MPa, and the wear volume of the brush bristle 31 is calculated.

[0035] Step S130, the distribution of brush bristles 31 before deformation is shown in the figure. Figure 8 In step (a), the fluid domain and the solid domain of each row of brush filaments 31 are used to update the fluid domain and the solid domain of brush filaments 31 in the solid model of the cross-branch tube bundle, thus obtaining the deformed geometric model under aerodynamic conditions. The deformed geometric model is used as the first model to perform the meshing step, that is, return to step S2 to perform meshing on the first model until the three-dimensional aerodynamic deformation result of brush filaments 31 reaches the first condition, and the iteration stops, thus completing the coupling of fluid-solid-thermal-grinding. During the process, when the inlet and outlet pressure ratio is 3 and the working time is 20 mins, see [the diagram]. Figure 8 In (b), the arrangement of the bristles at the bottom of the brush is severely deformed, which in turn interferes with the mainstream flow direction and forms a real feedback of flow-deformation.

[0036] The above are merely preferred embodiments of this application and do not limit the patent scope of this application. Any equivalent structural or procedural transformations made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

Claims

1. A highly efficient coupling method for multiple physical fields of flow-solid-thermal-grinding in a brush-type seal, characterized in that, include: A solid model of the forked tube bundle is established, which includes baffles, brush bundles, and fluid domains. Based on the parameters of the cross-branch tube bundle solid model, the contact normal pressure between the brush bristles and the rotor is determined, and the contact normal pressure between the brush bristles and the rotor is taken as the first contact normal pressure; wherein, the parameters include the interference between the brush bristles and the rotor; The cross-shaped tube bundle solid model is used as the first model, and a partitioning step is performed; the partitioning step is to perform meshing on the first model to obtain the meshed first model. The frictional heat flux density between the brush bristles and the rotor contact bottom surface is determined based on the first contact normal pressure, heat flow distribution coefficient, friction coefficient, rotor surface linear velocity, and the area of ​​the contact bottom surface between the brush bristles and the rotor. Using the frictional heat flux density between the brush bristles and the rotor contact surface as the boundary condition, CFD simulation was performed on the first model after mesh generation to obtain the static pressure. The three-dimensional aerodynamic load of the deformed brush bristles is determined based on the static pressure, and the contact normal pressure between the brush bristles and the rotor is re-determined based on the three-dimensional aerodynamic load of the deformed brush bristles. The three-dimensional aerodynamic deformation results of the brush bristles are determined based on the elastic modulus of the bristles and the three-dimensional aerodynamic load. The wear volume of each brush bristle is determined based on the wear coefficient between the brush bristles and the rotor, the redefined contact normal pressure between the brush bristles and the rotor, the linear velocity of the rotor surface, the wear time, and the hardness of the brush bristles. Based on the aerodynamic deformation results of the brush bristles and the wear volume of each brush bristle, the solid model of the cross-branch tube bundle is updated to obtain the deformation geometric model under aerodynamic force. The deformable geometric model is used as the first model, and the newly determined contact normal pressure between the brush bristles and the rotor is used as the first contact normal pressure. The division step is started until the three-dimensional aerodynamic deformation result of the brush bristles reaches the first condition, at which point the iteration stops and the coupling of fluid-solid-thermal-grinding is completed.

2. The efficient coupling method of multiple physics fields (fluid-solid-thermal-grinding) for brush sealing according to claim 1, characterized in that, The step of meshing the first model includes: The bristle bundle region is divided into several sub-domains along the radial direction of the bristles, and each sub-domain is meshed to obtain a mesh model for each sub-domain. In the mesh model of all subdomains, the nodes or elements of adjacent contact surfaces are mapped and spliced ​​one by one to obtain the first model after mesh generation; The bristle bundle region includes a fluid domain and a bristle solid domain.

3. The efficient coupling method for multi-physics fields of flow-solid-thermal-grinding in brush-type sealing according to claim 1, characterized in that, The step of determining the contact normal force between the brush bristles and the rotor based on the parameters of the cross-branch tube bundle solid model includes: Based on the interference between the brush bristles and the rotor, as well as the elastic modulus, diameter, length, and installation angle of the brush bristles, and the aerodynamic component of the brush bristles in the radial direction and the first preset relationship, the contact normal pressure between the brush bristles and the rotor is determined.

4. The efficient coupling method for multi-physics fields of flow-solid-thermal-grinding in brush-type sealing according to claim 1, characterized in that, The step of determining the frictional heat flux density between the brush bristles and the rotor contact surface based on the first contact normal force, heat flow distribution coefficient, friction coefficient, rotor surface linear velocity, and the area of ​​the brush bristles contacting the rotor contact surface includes: The frictional heat flux density of the contact surface between the brush bristles and the rotor is determined by the quotient of the product of the first contact normal pressure, the heat flow distribution coefficient, the friction coefficient, the rotor surface linear velocity, and the heat flow distribution coefficient, and the area of ​​the contact surface between the brush bristles and the rotor.

5. The efficient coupling method for multi-physics fields of brush seal flow-solid-thermal-grinding according to claim 1, characterized in that, Three-dimensional aerodynamic loads include the aerodynamic components of the brush filaments in the circumferential, axial, and radial directions; The three-dimensional aerodynamic load of the deformed brush filaments determined based on static pressure includes: Based on the component of static pressure in the corresponding direction and the length of the bristles, the aerodynamic force component of the bristles in each direction is determined, and the three-dimensional aerodynamic load of the bristles is obtained.

6. The efficient coupling method for multi-physics fields of brush seal flow-solid-thermal-grinding according to claim 1, characterized in that, The three-dimensional aerodynamic deformation result includes the three-dimensional aerodynamic deformation amount and the position after deformation; determining the three-dimensional aerodynamic deformation result of the brush bristles based on the elastic modulus of the bristles and the three-dimensional aerodynamic load includes: Using three-dimensional aerodynamic load as boundary conditions, the three-dimensional aerodynamic deformation of the brush bristles is determined based on the elastic modulus of the bristles, the length of the bristles, and the installation angle of the bristles. The position of the bristles after deformation is determined by the sum of the three-dimensional aerodynamic deformation of the bristles and the initial position of the bristles.

7. The efficient coupling method for multi-physics fields of brush seal flow-solid-thermal-grinding according to claim 1, characterized in that, The process involves updating the solid model of the cross-branch tube bundle based on the aerodynamic deformation results of the brush bristles and the wear volume of each bristle, resulting in a deformable geometric model under aerodynamic conditions, including: Based on the aerodynamic deformation results of the brush bristles and the wear volume of each brush bristle, the solid domains of each row of deformed brush bristles are generated. An envelope is constructed using the deformed brush bristles as the skeleton, and Boolean operations are used to remove the solid domains of the brush bristles and the baffles to obtain the deformed fluid domain. By utilizing the deformed fluid domain and the solid domain of each row of brush filaments, the solid model of the cross-branch tube bundle is updated to obtain the deformed geometric model under aerodynamic conditions.

8. The efficient coupling method for multi-physics fields of brush seal flow-solid-thermal-grinding according to claim 6, characterized in that, The first condition is that the three-dimensional aerodynamic deformation is less than 0.2% of the brush filament diameter.

9. The efficient coupling method for multi-physics fields of flow-solid-thermal-grinding in brush-type sealing according to claim 1, characterized in that, After determining the wear volume of each bristle, the method further includes, When the wear volume of any brush bristle reaches the preset volume, the wear of the current brush bristle is determined to have ended; The wear of the brush bundle ends when the wear volume of each row of brush filaments in the bundle reaches the preset volume.

10. A brush-type sealing fluid-solid-thermal-grinding multi-physics field high-efficiency coupling device, characterized in that, include: The model building module is used to build a solid model of the cross-branch tube bundle, which includes baffles, brush bundles, and a fluid domain. Based on the parameters of the cross-branch tube bundle solid model, the contact normal pressure between the brush and the rotor is determined, and the contact normal pressure between the brush and the rotor is taken as the first contact normal pressure. The parameters include the interference between the brush and the rotor. The partitioning module is used to take the cross-shaped tube bundle solid model as the first model and perform a partitioning step; the partitioning step is to perform meshing on the first model to obtain a meshed first model. The simulation module is used to determine the frictional heat flux density between the brush bristles and the rotor contact bottom surface based on the first contact normal pressure, heat flow distribution coefficient, friction coefficient, rotor surface linear velocity, and the area of ​​the brush bristles contacting the rotor bottom surface; and to perform CFD simulation on the first meshed model using the frictional heat flux density between the brush bristles and the rotor contact bottom surface as boundary conditions to obtain the static pressure. The aerodynamic load determination module is used to determine the three-dimensional aerodynamic load of the deformed brush bristles based on the static pressure, and to redetermine the contact normal pressure between the brush bristles and the rotor based on the three-dimensional aerodynamic load of the deformed brush bristles. The deformation result determination module is used to determine the three-dimensional aerodynamic deformation result of the brush bristles based on the elastic modulus and three-dimensional aerodynamic load. The wear volume determination module is used to determine the wear volume of each brush bristle based on the wear coefficient between the brush bristles and the rotor, the redefined contact normal pressure between the brush bristles and the rotor, the linear velocity of the rotor surface, the wear time, and the hardness of the brush bristles. The model update module is used to update the solid model of the cross-branch tube bundle based on the aerodynamic deformation results of the brush bristles and the wear volume of each brush bristle, so as to obtain the deformation geometry model under aerodynamic force. The iteration module is used to take the deformed geometric model as the first model and the redefined contact normal pressure between the brush bristles and the rotor as the first contact normal pressure to start the division step until the three-dimensional aerodynamic deformation result of the brush bristles reaches the first condition, at which point the iteration stops and the coupling of fluid-solid-thermal-grinding is completed.

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