Simulation calculation method for running state of water-lubricated guide bearing

Abstract

The invention discloses a simulation calculation method for the running state of a water-lubricated guide bearing. The simulation calculation method comprises the steps that simulation calculation parameters of the water-lubricated guide bearing are determined; three-dimensional models of the solid calculation area and the fluid calculation area are established respectively, and grids are divided; coupling the solid calculation area and the fluid calculation area, and establishing a fluid-solid coupling calculation model of the water-lubricated guide bearing; numerical solutions of the solid calculation area and the fluid calculation area are calculated respectively, and the calculation result of the solid calculation area and the calculation numerical solution of the fluid calculation area are subjected to two-way transmission for coupling to obtain a coupling calculation result; and performing post-processing on the coupling calculation result to obtain a running state simulation parameter. According to the simulation calculation method, the solid calculation area and the fluid calculation area are calculated respectively, numerical calculation data are coupled, and the running state of the fluid-solid coupled water-lubricated guide bearing is obtained through multiple iterations.

Description

Technical Field

[0001] The invention relates to the field of simulation calculation, and in particular to a simulation calculation method for the running state of a water-lubricated guide bearing. Background Art

[0002] Water-lubricated guide bearings are widely used in the rotating shafts of rotating machinery such as water pumps and turbines. Water-lubricated guide bearings balance the radial force of the rotating shaft, control the swing of the rotating shaft, and ensure the stable operation of the equipment. Compared with general oil-lubricated guide bearings, water-lubricated guide bearings have the advantages of simple structure, safety and energy saving, clean and environmental protection, and low maintenance costs. Since the viscosity of water is much lower than that of conventional lubricating oil, water-lubricated guide bearings have problems such as low load-bearing capacity, small liquid film thickness, and complex fluid flow patterns. The current operating status monitoring technology used for water-lubricated guide bearings cannot accurately reflect the operating status of the bearings.

[0003] In addition, the small liquid film thickness and relatively complex flow state in water-lubricated guide bearings also make the numerical calculation of water-lubricated guide bearings more and more difficult. It is necessary to develop a simulation calculation method that can be applied to water-lubricated guide bearings based on the characteristics of water-lubricated guide bearings. Summary of the invention

[0004] The purpose of the present invention is to provide a simulation calculation method for the running state of a water-lubricated guide bearing.

[0005] To achieve the above object, the present invention provides a simulation calculation method for the running state of a water-lubricated guide bearing, the water-lubricated guide bearing includes a solid calculation area and a fluid calculation area, and the simulation calculation method comprises:

[0006] S10, determining simulation calculation parameters of the water-lubricated guide bearing;

[0007] S20, establishing a three-dimensional model of the solid calculation area and dividing the mesh, establishing a three-dimensional model of the fluid calculation area and dividing the mesh;

[0008] S30, coupling the solid calculation region and the fluid calculation region to establish a fluid-solid coupling calculation model of the water-lubricated guide bearing;

[0009] S40, respectively calculating numerical solutions for the solid calculation region and the fluid calculation region of the water-lubricated guide bearing, and bidirectionally transmitting and coupling the calculation result of the solid calculation region and the numerical solution of the fluid calculation region to obtain a coupled calculation result;

[0010] S50, post-processing the coupling calculation results to obtain operation state simulation parameters.

[0011] Preferably, in step S10, the simulation calculation parameters include the spindle design radial load, the spindle diameter, the single-sided clearance, the guide bearing thickness of the water-lubricated guide bearing, the guide bearing length of the water-lubricated guide bearing, the guide bearing material density, the elastic modulus of the guide bearing material, the Poisson's ratio of the guide bearing material, the spindle material, the spindle speed, the water supply pressure of the water inlet of the water-lubricated guide bearing, the water supply temperature, and the outlet pressure of the water outlet of the water-lubricated guide bearing.

[0012] Preferably, in step S20, the solid calculation area includes the guide bushing and the main shaft of the water-lubricated guide bearing.

[0013] Preferably, in step S20, the fluid calculation area includes the lubricating water film at the gap between the guide bush of the water-lubricated guide bearing and the main shaft.

[0014] Preferably, the solid calculation region and the fluid calculation region are meshed, and a hexahedral unit mesh is generated by a sweeping method.

[0015] Preferably, in step S30, coupling the solid calculation area and the fluid calculation area specifically includes: setting the outer surface of the guide bearing as a fixed constraint; constraining the lateral axial movement freedom and rotational freedom of the main shaft; and setting the inner surface of the guide bearing and the side of the main shaft as fluid-solid coupling surfaces.

[0016] Preferably, in step S40, the solid calculation region is solved using Newmarks-β direct integration method.

[0017] Preferably, in step S40, for the fluid calculation region, a second-order discretization format is used to discretize the pressure term and the momentum term, a first-order upwind format is used to discretize the turbulence term, and a second-order implicit time integration scheme is used in time advancement.

[0018] Preferably, in step S40, the calculation results of the solid calculation area and the calculation numerical solution of the fluid calculation area are bidirectionally transmitted for coupling, and the coupled calculation results obtained specifically include: solving in the solid calculation area and the fluid calculation area respectively, and in each iterative step, the pressure on the fluid-solid coupling interface of the fluid calculation area is transmitted to the solid calculation area; the displacement on the fluid-solid coupling interface of the solid calculation area is transmitted to the fluid calculation area.

[0019] Preferably, the bidirectional data transmission between the solid computing region and the fluid computing region is repeated until a balance state is reached.

[0020] In summary, compared with the prior art, the simulation calculation method for the running state of the water-lubricated guide bearing provided by the present invention has the following beneficial effects:

[0021] The simulation calculation method for the operating state of a water-lubricated guide bearing of the present invention calculates the solid calculation area and the fluid calculation area of ​​the water-lubricated guide bearing respectively and couples the numerical calculation data, performs multiple iterations to obtain the operating state of the water-lubricated guide bearing with fluid-solid coupling, and obtains the operating characteristic parameters of the water-lubricated guide bearing such as eccentricity, water film thickness, pressure distribution, solid deformation and friction power consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is an overall flow chart of the simulation calculation method for the operating state of the water-lubricated guide bearing of the present invention.

[0023] Figure 2 It is a schematic diagram of the solid calculation area of ​​the water-lubricated guide bearing in the present invention.

[0024] Figure 3 It is a schematic diagram of the fluid calculation area of ​​the water-lubricated guide bearing in the present invention.

[0025] Figure 4 The cloud diagram of water film pressure distribution of a water-lubricated guide bearing obtained by the simulation calculation method of the present invention.

[0026] Figure 5 The deformation distribution cloud diagram of the guide bush of the water-lubricated guide bearing obtained by the simulation calculation method of the present invention.

[0027] Description of reference numerals:

[0028] Solid Computation Area 110

[0029] Spindle 111

[0030] Guide bearing 112

[0031] Clearance between guide bearing and main shaft 113

[0032] Fluid calculation area 120

[0033] Water film and guide bearing contact surface 121

[0034] Water film and spindle contact surface 122

[0035] Lubrication water inlet 123

[0036] Lubrication water outlet 124 DETAILED DESCRIPTION

[0037] The following will be combined with the attached embodiment of the present invention Figure 1 ~Attached Figure 5 , the technical solutions, structural features, objectives achieved and effects in the embodiments of the present invention are described in detail.

[0038] It should be noted that the drawings are in a very simplified form and use non-precise proportions. They are only used to conveniently and clearly assist in explaining the embodiments of the present invention, and are not used to limit the conditions for the implementation of the present invention. Therefore, they have no substantive technical significance. Any structural modification, change in proportional relationship or adjustment of size, without affecting the effects and purposes that can be achieved by the present invention, should still fall within the scope of the technical content disclosed by the present invention.

[0039] It should be noted that, in the present invention, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only the elements explicitly listed, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0040] like Figure 1 As shown, the present invention provides a simulation calculation method for the running state of a water-lubricated guide bearing. The water-lubricated guide bearing includes a solid calculation area 110 and a fluid calculation area 120, and the simulation calculation method includes:

[0041] S10, determine the simulation calculation parameters of the water-lubricated guide bearing. The simulation calculation parameters include the spindle design radial load, spindle diameter, unilateral clearance, thickness of the guide bush 112 of the water-lubricated guide bearing, length of the guide bush 112 of the water-lubricated guide bearing, density of the guide bush material, elastic modulus of the guide bush material, Poisson's ratio of the guide bush material, spindle material, spindle speed, water supply pressure of the water flow inlet of the water-lubricated guide bearing, water supply temperature, and outlet pressure of the water flow outlet of the water-lubricated guide bearing. The unilateral clearance refers to the clearance 113 between the guide bush and the spindle.

[0042] In this embodiment, the specific parameters are set as follows. The specific parameter values ​​are only used as examples to explain this embodiment and do not constitute a limitation on the scope of application of the simulation calculation method of the present invention. The spindle design radial load is 20N, the spindle diameter is 44mm, the single-side clearance is 0.5mm, the thickness of the guide bush 112 of the water-lubricated guide bearing is 8mm, the length of the guide bush 112 of the water-lubricated guide bearing is 22mm, and the density of the guide bush material is 1000kg / m 3 , elastic modulus 1GPa, Poisson's ratio 0.47, the material of the guide bearing 112 is polyurethane; the material of the main shaft 111 is steel, the main shaft speed is set to 3000rpm, the water supply pressure of the water inlet of the water-lubricated guide bearing is 0.2MPa, the water supply temperature is 20℃, and the outlet pressure of the water outlet of the water-lubricated guide bearing is atmospheric pressure.

[0043] S20, establish a three-dimensional model of the solid calculation area 110 and divide it into grids, establish a three-dimensional model of the fluid calculation area 120 and divide it into grids. Figure 2 As shown, the solid computing region 110 includes a guide bush 112 of a water-lubricated guide bearing and a main shaft 111. Figure 3 As shown, the fluid calculation area 120 includes the lubricating water film at the gap 113 between the guide bush of the water-lubricated guide bearing and the main shaft. In this embodiment, a three-dimensional model of the solid calculation area 110 and the fluid calculation area 120 is established in the ANSYS SpaceClaim module, and the established three-dimensional model is directly imported into the ANSYS Meshing module for three-dimensional model network division, and a hexahedral unit mesh is generated by a sweeping method, and the generated meshes are all hexahedral units.

[0044] In other embodiments, other modeling modules may be selected to establish the three-dimensional models of the solid computing region 110 and the fluid computing region 120 , which is not limited here.

[0045] S30, coupling the solid calculation area 110 and the fluid calculation area 120, and establishing a fluid-solid coupling calculation model for the water-lubricated guide bearing. In this embodiment, a bidirectional fluid-solid coupling model of the fluid calculation area 120 and the solid calculation area 110 is established based on the ANSYS Workbench platform, the divided solid calculation grid is imported into the Transient Structure structural analysis module, and the material parameters such as the density and elastic modulus of the guide bearing 112 and the main shaft 111 are set. The process of coupling the solid calculation area 110 and the fluid calculation area 120 specifically includes: setting the outer surface of the guide bearing 112 as a fixed constraint; constraining the lateral axial movement degree of freedom and rotation degree of freedom of the main shaft 111; and setting the inner surface of the guide bearing 112 and the side of the main shaft 111 as a fluid-solid coupling surface. In order to suppress excessive grid movement, prevent the appearance of negative volume grids, and ensure the numerical stability of the calculation, two COMBIN14 units parallel to the upper and lower surfaces of the main shaft 111 and perpendicular to each other are set at the center of mass of the main shaft 111. In the finite element software, COMBIN 14 units are used to simulate spring-damper systems. In mechanical analysis, COMBIN14 units can be used to impose elastic constraints and damping constraints. Two mutually perpendicular COMBIN14 units are set at the center of mass of the main shaft 111, and the two units are perpendicular to each other. For example, one COMBIN14 unit may be along the axial direction of the main shaft 111, and the other is perpendicular to the axial direction. Setting such a grid structure can play an effect of suppressing excessive grid movement during the simulation process. Specifically, during the calculation process, the movement of the main shaft 111 will cause the grid to deform. If the grid moves too much, the calculation results may be distorted or even unable to converge. The two mutually perpendicular COMBIN14 units restrict the movement of the main shaft 111 from different directions. For example, when the main shaft 111 has a large displacement trend in one direction, the corresponding COMBIN14 unit will generate a reverse force according to its spring-damper characteristics to prevent excessive displacement. In addition, when the grid movement is uncontrolled, the grid may be distorted and deformed, and in severe cases, the grid may have a negative volume. Negative volume grids are not allowed in numerical calculations because they will cause the calculation to fail. By constraining the centroid of the main axis through the COMBIN14 unit, the deformation of the grid can be made more reasonable, avoiding the occurrence of grid folding and other negative volume situations. This ensures the numerical stability of the calculation. The existence of the COMBIN14 unit keeps the movement of the structure and the grid deformation within a controllable range, ensuring the reasonable changes of physical quantities such as system stiffness during the calculation process.

[0046] The damping coefficient of the unit is set to 100Ns / mm; the radial load of the water smooth guide bearing is loaded on the center of mass of the main shaft 111 in the form of a distal force, the magnitude of the force is 20N, and the direction is the positive direction of the x-axis (the x-axis direction is as follows Figure 2). The divided fluid calculation area 120 mesh is imported into the Fluent fluid analysis module, and the fluid physical properties are set to the physical properties of water at 20°C. The turbulence model selects the SST k-ω two-equation model; the lubricating water inlet 123 of the water-lubricated guide bearing is set to a pressure inlet with a pressure of 0.2MPa; the lubricating water outlet 124 is set to a pressure outlet with a pressure of 0MPa; the inner surface of the fluid calculation area 120 in contact with the main shaft 111, that is, the water film and the main shaft contact surface 122 is set to a non-slip rotating wall surface, and the rotation speed is set to 3000rpm; the outer surface of the fluid calculation area 120 in contact with the guide bearing 112 of the water-lubricated guide bearing, that is, the water film and the guide bearing contact surface 121 is set to a non-slip wall surface; the Fluent dynamic mesh function is turned on, and the mesh reconstruction method selects Diffusion. Using the default mesh reconstruction parameters, both the inner and outer surfaces of the water film in the fluid domain are created as fluid-solid coupling interfaces. After the boundary conditions of the solid calculation area 110 and the fluid calculation area 120 are set, the transient structure and the fluid are connected through the ANSYS System Coupling module to realize the bidirectional data transmission on the fluid-solid coupling surface.

[0047] S40, respectively calculate numerical solutions for the solid calculation region 110 and the fluid calculation region 120 of the water-lubricated guide bearing. In this embodiment, the solver of the solid calculation region 110 is ANSYS APDL, and the solid calculation region 110 is solved using the Newmarks-β direct integration method. The Newmarks-β method is a step-by-step integration method that gradually calculates the response of the structure at each time step starting from the initial moment according to a certain time step. By discretizing the time interval, the continuous dynamic problem is converted into a series of algebraic equations at discrete time points for solution.

[0048] The solution of the fluid calculation area 120 is performed in Fluent, using a second-order discrete format to discretize the pressure term and momentum term, a first-order upwind format to discretize the turbulence term, a second-order implicit time integration scheme for time advancement, and the SIMPLEC pressure-velocity coupling method to iteratively solve the flow field. At the beginning of the calculation, the solid calculation area 110 and the fluid calculation area 120 are solved respectively. In this embodiment, based on the bidirectional data transmission function of the ANSYS System Coupling module, in each iterative step, the pressure on the fluid-solid coupling interface of the fluid calculation area 120 is transferred to the solid calculation area 110; the displacement on the fluid-solid coupling interface of the solid calculation area 110 is transferred to the fluid calculation area 120. During the calculation process, the main shaft 111 will undergo radial translation and deformation under the combined action of the water film pressure and the radial load, and the inner surface of the guide bearing 112 will deform under the action of the water film pressure. The combined effect of the two will change the water film flow field and in turn change the water film pressure; the two-way data transmission between the solid calculation area 110 and the fluid calculation area 120 is repeated until a balance state is reached. When a balance state is reached, the displacement and pressure transmitted on the fluid-solid coupling interface reach the convergence standard.

[0049] S50. Post-process the coupling calculation results to obtain the operating state simulation parameters. After the previous steps are completed, the calculation result files of the flow field and structural field are imported into the post-processing module CFD-Post in the ANSYS Workbench platform. The eccentricity and water film thickness of the water-lubricated guide bearing can be obtained from the deformed flow field geometry information. As shown in the figure, the operating eccentricity of the water-lubricated guide bearing of this embodiment is 0.4164, and the minimum operating water film thickness is 0.0303mm; the water film pressure distribution and solid deformation distribution of the guide bearing are displayed using the CFD-Post Contour function. The water film pressure distribution cloud map and the deformation distribution cloud map of the guide bearing 112 of this embodiment are shown as follows: Figure 4 , Figure 5 As shown; the friction torque on the main shaft 111 of this embodiment is obtained by the CFD-Post torque function, which is 0.011Nm, and the corresponding guide bearing friction power consumption is 3.454W.

[0050] In this embodiment, the implementation process of the simulation calculation method for the operating state of a water-lubricated guide bearing of the present invention is introduced by taking the ANSYS simulation platform as an example. However, the simulation calculation method for the operating state of a water-lubricated guide bearing of the present invention is not limited to the ANSYS simulation platform, and can also be applied to other simulation platforms such as COMSOL Multiphysics, ADINA, etc., which is not limited here.

[0051] The simulation calculation method for the running state of the water-lubricated guide bearing of the present invention takes into account the bidirectional coupling between the elastic deformation of the main shaft 111 and the water-lubricated guide bearing and the lubricating water flow field, and can predict the running state of the water-lubricated guide bearing under the radial load of the given main shaft 111 with less computing resources, and obtains the running characteristic parameters of the water-lubricated guide bearing such as eccentricity, water film thickness, pressure distribution, solid deformation and friction power consumption by calculation. The simulation calculation method for the running state of the water-lubricated guide bearing of the present invention has the advantages of good calculation accuracy, high efficiency, easy operation and strong engineering practicality.

[0052] Although the content of the present invention has been described in detail through the above preferred embodiments, it should be appreciated that the above description should not be considered as a limitation of the present invention. After reading the above content, it will be apparent to those skilled in the art that various modifications and substitutions of the present invention will occur. Therefore, the protection scope of the present invention should be limited by the appended claims.

Claims

1. A simulation calculation method for the running state of a water-lubricated guide bearing, characterized in that: The water-lubricated guide bearing includes a solid calculation area and a fluid calculation area, and the simulation calculation method includes: S10, determining simulation calculation parameters of the water-lubricated guide bearing; S20, establishing a three-dimensional model of the solid calculation area and dividing the mesh, establishing a three-dimensional model of the fluid calculation area and dividing the mesh; S30, coupling the solid calculation region and the fluid calculation region to establish a fluid-solid coupling calculation model of the water-lubricated guide bearing; S40, respectively calculating numerical solutions for the solid calculation region and the fluid calculation region of the water-lubricated guide bearing, and bidirectionally transmitting and coupling the calculation result of the solid calculation region and the numerical solution of the fluid calculation region to obtain a coupled calculation result; S50, post-processing the coupling calculation results to obtain operation state simulation parameters.

2. The simulation calculation method according to claim 1, characterized in that: In step S10, the simulation calculation parameters include the spindle design radial load, the spindle diameter, the single-sided clearance, the guide bearing thickness of the water-lubricated guide bearing, the guide bearing length of the water-lubricated guide bearing, the guide bearing material density, the elastic modulus of the guide bearing material, the Poisson's ratio of the guide bearing material, the spindle material, the spindle speed, the water supply pressure of the water inlet of the water-lubricated guide bearing, the water supply temperature, and the outlet pressure of the water outlet of the water-lubricated guide bearing.

3. The simulation calculation method according to claim 1, characterized in that: In step S20, the solid calculation area includes the guide bushing and the main shaft of the water-lubricated guide bearing.

4. The simulation calculation method according to claim 3, characterized in that: In step S20, the fluid calculation area includes the lubricating water film at the gap between the guide bush of the water-lubricated guide bearing and the main shaft.

5. The simulation calculation method according to claim 4, characterized in that: The solid calculation region and the fluid calculation region are meshed, and a hexahedral unit mesh is generated by a sweeping method.

6. The simulation calculation method according to claim 5, characterized in that: In step S30, coupling the solid calculation area and the fluid calculation area specifically includes: setting the outer surface of the guide bearing as a fixed constraint; constraining the lateral axial movement freedom and rotational freedom of the main shaft; and setting the inner surface of the guide bearing and the side of the main shaft as fluid-solid coupling surfaces.

7. The simulation calculation method according to claim 6, characterized in that: In step S40, the solid calculation region is solved using the Newmarks-β direct integration method.

8. The simulation calculation method according to claim 7, characterized in that: In step S40, for the fluid calculation area, a second-order discretization format is used to discretize the pressure term and the momentum term, a first-order upwind format is used to discretize the turbulence term, and a second-order implicit time integration scheme is used in time advancement.

9. The simulation calculation method according to claim 8, characterized in that: In step S40, the calculation results of the solid calculation area and the calculation numerical solution of the fluid calculation area are bidirectionally transmitted and coupled to obtain the coupled calculation results, which specifically include: solving in the solid calculation area and the fluid calculation area respectively, and in each iterative step, transferring the pressure on the fluid-solid coupling interface of the fluid calculation area to the solid calculation area; transferring the displacement on the fluid-solid coupling interface of the solid calculation area to the fluid calculation area.

10. The simulation calculation method according to claim 9, characterized in that: The bidirectional data transmission between the solid computing region and the fluid computing region is repeated until a balance state is reached.

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