CFD (Computational Fluid Dynamics) analysis method for influence of guide wheel blade surface damage on transmission torque and regulation and control device

Abstract

The invention relates to a CFD analysis method for influence of guide wheel blade surface damage on transmission torque and a regulation and control device. The analysis method comprises the following steps: defining micro-damage characteristics; cFD pretreatment: selecting a single guide runner as a fluid computational domain based on defined micro-damage characteristics, and establishing a guide runner geometric model of the micro-damage characteristics; cFD solving calculation and post-processing are carried out, the established guide wheel runner model is solved based on a finite volume method, and circulation flow data under different micro-damage characteristics are obtained; and fitting is carried out to obtain a function relation between different micro-damage characteristics and circulating flow data, and a function relation between different micro-damage characteristic parameters and transmission torque is established based on a torque calculation formula, so that reliable data support is provided for damage influence evaluation. Analysis is applied to a regulation and control device, the regulation and control device comprises a mounting base, a heat conduction base, a piezoelectric ceramic driver, a strain gauge type displacement sensor, a flexible metal diaphragm and a control unit, and active regulation and control of torque are achieved based on a PID control system of the control unit.

Description

Technical Field

[0001] This invention relates to the field of oil drilling equipment design and condition monitoring technology, and in particular to a CFD analysis method and control device for the effect of guide wheel blade surface damage on transmission torque. Background Technology

[0002] Hydraulic drilling tools are core power transmission components in oil drilling operations, and their performance directly affects drilling efficiency and safety. As a key component of hydraulic drilling tools, the guide wheel works for extended periods in high-pressure, high-speed drilling fluid containing abrasive particles. Its working surface is highly susceptible to minor damage from erosion, wear, or impact, which in turn affects the stability of the transmission torque.

[0003] In patent CN114962583A, the extension amount of the first telescopic vane is controlled by the coordinated operation of the first driver and the first elastic element, thereby adjusting the flow rate of the hydraulic torque converter during operation. In patent CN221462875U, by setting up a guide wheel housing, pump wheel, guide wheel body, adjusting block, first spring, positioning block, and guide wheel vane, the first spring and positioning block are used to achieve different angle adjustments of the adjusting block, thus achieving different angle adjustments of the guide wheel vane and resulting in different flow rates.

[0004] The technical solutions proposed in the aforementioned patents each have their advantages. However, existing technical solutions lack precise analysis and active control technology for the changes in transmission torque when the guide wheel blades in hydraulic drilling tools are subjected to micro-damage. Therefore, there is an urgent need for a method that can accurately analyze the quantitative relationship between micro-damage and transmission torque, and on this basis, develop a device that can actively control torque to improve the dynamic stability and multi-condition adaptability of hydraulic drilling tools. Summary of the Invention

[0005] In view of the shortcomings of the prior art, the purpose of this invention is to provide a CFD analysis method and control device for the effect of guide wheel blade surface damage on transmission torque, so as to solve one or more problems in the prior art.

[0006] To achieve the above objectives, the technical solution of the present invention is as follows: The CFD analysis method for the impact of guide vane surface damage on transmission torque is as follows: Define micro-damage characteristics, including their distribution at different locations, shapes, and sizes on the surface of the guide vane blades; CFD preprocessing is performed to establish a guide wheel geometric model with micro-damage characteristics, and a single guide wheel flow channel is selected as the fluid computation domain; CFD calculation and post-processing: Based on the finite volume method, the selected guide wheel flow channel model is solved to obtain circulating flow data under different micro-damage characteristics; The functional relationship between different micro-damage characteristics and circulating flow data was obtained by fitting, and the functional relationship between different micro-damage characteristic parameters and transmission torque was established based on the torque calculation formula.

[0007] Furthermore, the different locations are defined as the different axial distances at which the micro-damage is located at the inlet of the guide wheel blade; the different shapes are defined as structural protrusions or pits on the working surface of the guide wheel flow channel model, including cylindrical, triangular prism and quadrangular prism shapes.

[0008] Furthermore, the different sizes are defined as follows: For protrusions or depressions in cylindrical structures, the micro-damage characteristic parameters are the diameter and height of the cylinder's base. For protrusions or depressions in a triangular prism structure, the micro-damage characteristic parameters are the side length and height of the base of the triangular prism. For protrusions or depressions in a quadrangular prism structure, the micro-damage characteristic parameters are the side length and height of the base of the quadrangular prism.

[0009] Furthermore, the selected guide wheel flow channel model includes the inlet face, outlet face, working face, non-working face, inner ring face, and outer ring face.

[0010] Furthermore, the selection of a single guide wheel channel as the fluid computation domain includes the following steps: A guide wheel flow channel mesh model was established based on hexahedral unstructured mesh generation; Assign fluid physical properties to the mesh model, set the turbulence model, and set boundary conditions.

[0011] Furthermore, the functional relationship between the different micro-damage characteristics and the circulating flow data includes: The functional relationship between circulation flow rate and axial distance of micro-damage is shown in the following formula:

[0012] In the formula, A 1. A 2. A 3. A 4 represents the shape correlation coefficient, which is determined based on the geometry of the damage. d This represents the axial distance of the micro-damage. The functional relationship between circulation flow rate and micro-damage height is shown in the following equation:

[0013] In the formula, P 1. P 2. P 3. P 4 represents the shape correlation coefficient, which is determined based on the geometry of the damage. h The height of the micro-damage; The functional relationship between the circulation flow rate and the micro-damaged bottom surface size is shown in the following equation:

[0014] In the formula, C 1. C 2. C 3. C 4 represents the shape correlation coefficient, which is determined based on the geometry of the damage. s The dimensions of the bottom surface with minimal damage.

[0015] Furthermore, the torque calculation formula is shown below:

[0016] In the formula: ρ For the working oil density, Q For circulating flow, R D2 The guide wheel exit radius, β D2 For the guide wheel exit angle, F D2 The cross-sectional area of ​​the guide wheel exit is... R T2 Where is the turbine outlet radius. β T2 For turbine outlet angle, F T2 The turbine outlet cross-sectional area, n T This refers to the turbine speed.

[0017] Furthermore, the functional relationships between different micro-damage characteristic parameters and transmission torque include: The functional relationship between transmission torque and axial distance of micro-damage is shown in the following formula:

[0018] In the formula, a 0、 a 1. a 2. a 3. a 4. a 5. a 6 is the shape correlation coefficient, determined based on the geometry of the damage. d This represents the axial distance of the micro-damage. The functional relationship between transmission torque and micro-damage height is shown in the following equation:

[0019] In the formula, p 0、 p 1. p 2. p3. p 4. p 5. p 6 is the shape correlation coefficient, determined based on the geometry of the damage. h The height of the micro-damage; The functional relationship between transmission torque and the size of the micro-damaged bottom surface is shown in the following formula:

[0020] In the formula, c 0、 c 1. c 2. c 3. c 4. c 5. c 6 is the shape correlation coefficient, determined based on the geometry of the damage. s The dimensions of the bottom surface with minimal damage.

[0021] A control device is disclosed, based on the aforementioned CFD analysis method for the influence of guide wheel blade surface damage on transmission torque. The device includes a mounting base, a thermally conductive base, a piezoelectric ceramic actuator, a strain gauge displacement sensor, a flexible metal diaphragm, and a control unit. The mounting base is fitted into and fixedly connected to the groove of the guide wheel blade. The flexible metal diaphragm is disposed on the mounting base with its outer surface adapted to the surface of the guide wheel blade. The thermally conductive base is fixed within the mounting base at one end away from the flexible metal diaphragm. The piezoelectric ceramic actuator is disposed within the mounting base and fixedly connected to the inner surface of the flexible metal diaphragm. The strain gauge displacement sensor is disposed within the mounting base and fitted to the flexible metal diaphragm.

[0022] Furthermore, the control unit is electrically coupled to the piezoelectric ceramic actuator and the strain gauge displacement sensor respectively; the control unit acts on the control device based on a PID control system.

[0023] Compared with the prior art, the beneficial technical effects of the present invention are as follows: This invention utilizes CFD analysis to accurately establish a quantitative functional relationship between the characteristic parameters of micro-damage on the guide vane surface and the circulating flow rate and transmission torque, providing reliable data support for damage impact assessment. Furthermore, the control device designed based on this analysis generates controllable microstructures on the vane surface using a piezoelectric ceramic actuator. This allows for dynamic adjustment of the deformation of the flexible metal diaphragm according to actual torque requirements or to compensate for torque losses caused by existing damage, achieving active, real-time, and precise adjustment of the transmission torque. This effectively improves the dynamic stability and operational reliability of hydraulic drilling tools under complex operating conditions. Attached Figure Description

[0024] Figure 1A schematic flowchart of CFD analysis of the effect of guide wheel blade surface damage on transmission torque is shown in an embodiment of the present invention.

[0025] Figure 2 The diagram shows damage to the working surface of the guide wheel in different shapes according to an embodiment of the present invention.

[0026] Figure 3 A schematic diagram of the fluid domain calculation model of the guide wheel flow channel according to an embodiment of the present invention is shown.

[0027] Figure 4 A schematic diagram of grid division according to an embodiment of the present invention is shown.

[0028] Figure 5 A schematic diagram of the installation of the control device on the guide wheel blades according to an embodiment of the present invention is shown.

[0029] Figure 6 A schematic diagram of the component installation of the control device according to an embodiment of the present invention is shown.

[0030] Figure 7 A block diagram illustrating the principle of the PID closed-loop control system of the control device according to an embodiment of the present invention is shown.

[0031] Figure 8 The diagram shows the displacement response variation curve of the piezoelectric ceramic actuator in a closed-loop control system according to an embodiment of the present invention.

[0032] The following are labeled in the attached diagram: 1. Mounting base; 2. Thermally conductive base; 3. Piezoelectric ceramic actuator; 4. Strain gauge displacement sensor; 5. Flexible metal diaphragm; 6. Control unit; 7. Guide wheel blade. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of this invention clearer, the following detailed description, in conjunction with the accompanying drawings and specific embodiments, provides a further detailed explanation of the CFD analysis method and control device for the influence of guide wheel blade surface damage on transmission torque proposed in this invention. The advantages and features of this invention will become clearer from the following description. It should be noted that the accompanying drawings are in a very simplified form and use non-precise proportions, used only to facilitate and clearly illustrate the purpose of the embodiments of this invention. Please refer to the accompanying drawings to make the objectives, features, and advantages of this invention more apparent and understandable. It should be understood that the structures, proportions, sizes, etc., depicted in the accompanying drawings are only for illustrative purposes to aid those skilled in the art and are not intended to limit the implementation conditions of this invention. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to the size, without affecting the effects and objectives achieved by this invention, should still fall within the scope of the technical content disclosed in this invention.

[0034] Please see Figure 1The CFD analysis method for the effect of guide wheel blade surface damage on transmission torque includes the following steps: Step 1: Define micro-damage characteristics, including different locations, shapes, and sizes distributed on the surface of the guide vane.

[0035] The different positions are defined as the different axial distances at which the micro-damage is located at the inlet of the guide wheel blade. Different axial distances will directly affect the impact position and flow separation state of the fluid on the surface of the guide wheel blade, thereby changing the pressure distribution and velocity gradient of the flow field.

[0036] For further details, please refer to [link / reference]. Figure 2 The different shapes are defined on the working surface of the guide wheel flow channel model, including cylinders, i.e. Figure 2 a) Triangular prism Figure 2 The middle b and the square prism are Figure 2 The structure of C is damaged by protrusions or pits.

[0037] Furthermore, the different sizes are defined as follows: For cylindrical protrusions or pits, the micro-damage characteristic parameters are the diameter and height of the cylinder's base. The base diameter determines the lateral extent of the damage's contact with the fluid, while the height affects the degree of blockage and the depth of disturbance as the fluid flows through the damaged area. For triangular prism protrusions or pits, the micro-damage characteristic parameters are the side length of the prism's base and its height. The side length of the base directly relates to the area occupied by the damage in the lateral direction of the flow channel, while the height determines the resistance strength to the fluid movement in the mainstream direction. For a quadrangular prism-shaped protrusion or pit, the micro-damage characteristic parameters are the side length of the base and the height of the quadrangular prism. The size of the side length of the base will change the location of the boundary layer separation point when the fluid is damaged around it, while the height will affect the longitudinal propagation distance of the flow field disturbance.

[0038] The combination of the above-mentioned micro-damage characteristic parameters can comprehensively characterize the geometric morphology of different types of micro-damage, providing basic data support for the accurate simulation of flow field characteristics in subsequent CFD simulations, and enabling the analysis results to more realistically reflect the influence of actual damage on transmission torque.

[0039] Step 2: CFD preprocessing, establish a guide wheel geometric model with micro-damage characteristics, and select a single guide wheel flow channel as the fluid computation domain.

[0040] Please see Figure 3The selected guide wheel flow channel geometry model includes an inlet surface, an outlet surface, a working surface, a non-working surface, an inner annular surface, and an outer annular surface. The inlet surface is connected to the pump wheel outlet, receiving high-pressure oil from the pump wheel. The outlet surface is connected to the turbine inlet, delivering the oil, after being guided by the guide wheel blades, to the turbine. The working surface is the surface of the guide wheel blades that bears the impact of the main flow, and the non-working surface is the opposite surface. The inner and outer annular surfaces are connected to the hub and shell of the guide wheel, respectively, forming a closed flow channel space. A single complete guide wheel flow channel is selected from the complete guide wheel geometry model as the fluid computation domain for CFD analysis. Due to the circumferential symmetry of the guide wheel structure, the flow field characteristics of a single channel can represent the distribution law of the overall flow field. This approach can significantly reduce the number of meshes and computational costs while ensuring the accuracy of the analysis results.

[0041] Furthermore, the selection of a single guide wheel channel as the fluid computation domain includes the following steps: A guide wheel flow channel mesh model is established based on hexahedral unstructured mesh generation: Please refer to the following: Figure 4 After selecting the individual guide wheel flow channel for CFD analysis, a hexahedral unstructured mesh is used to divide the guide wheel flow channel. This generates high-quality meshes in complex geometric regions, ensuring low anisotropy of mesh elements and thus improving the accuracy of flow field calculations. For local areas containing micro-damage features, mesh refinement is performed, with the refinement level determined based on the damage size.

[0042] Assign fluid physical properties to the mesh model, set up a turbulence model, and set boundary conditions: Regarding fluid physical properties, these include fluid density, viscosity, specific heat, and thermal conductivity. In this embodiment, the fluid density is defined as 875 kg / m³. 3 The parameters, such as viscosity of 0.00189 kg / (m•s), specific heat of 2000 J / (kg•K), and thermal conductivity of 0.13 W / (m•K), were set with reference to the physical properties of commonly used working fluids in actual hydraulic transmission systems, ensuring consistency between the simulation environment and engineering application scenarios.

[0043] In this embodiment, the turbulence model is the standard RNG model, which includes the turbulent kinetic energy equation and the turbulent dissipation rate equation. k - ɛ The model has high computational accuracy and stability when simulating complex flows in rotating machinery. It can accurately capture the turbulent pulsation characteristics and vortex evolution process in the flow field, and is especially suitable for simulating local strong disturbance flow fields caused by micro-damage on the surface of guide wheel blades.

[0044] Boundary condition settings include pressure inlet boundary conditions, pressure outlet boundary conditions, and a no-slip wall. In this embodiment, a pressure of 0.50 MPa and a temperature of 403 K are used as the inlet boundary conditions, and a pressure of 0.42 MPa and a temperature of 405 K are used as the outlet boundary conditions. The wall condition is set to a no-slip wall to conform to the interaction law between fluid and solid wall in actual engineering, and to accurately reflect the velocity gradient and boundary layer development state near the wall.

[0045] Step 3: CFD solution and post-processing. Based on the finite volume method, the selected guide wheel flow channel model is solved to obtain the circulating flow data under different micro-damage characteristics.

[0046] In the CFD solution calculation stage, the SIMPLE method with a second-order upwind discretization scheme under the finite volume method framework is used for discretization to improve the calculation accuracy. During the calculation process, the residual is set to be no less than 10. -6 The order of magnitude is crucial to ensure the stability of the numerical solution for the flow field. After the solution is obtained, post-processing analysis is performed on the calculation results to extract the circulating flow rate data corresponding to different micro-damage characteristics.

[0047] Step 4: Fit the functional relationship between different micro-damage characteristics and circulating flow data, and establish the functional relationship between different micro-damage characteristic parameters and transmission torque based on the torque calculation formula.

[0048] Multiple sets of data fitting were performed on the circulating flow data extracted in step 3 with different micro-damage characteristic parameters to obtain the functional relationship between circulating flow and each micro-damage characteristic parameter. Then, the circulating flow variable was substituted into the torque calculation formula to establish a direct functional relationship between transmission torque and the axial distance, height, and bottom dimension of the micro-damage. This ultimately achieves a quantitative characterization of transmission torque through micro-damage characteristic parameters. In practical applications, based on the specific type of micro-damage detected on the guide wheel blade surface, such as cylindrical pits or triangular prism protrusions, the corresponding shape correlation coefficient can be determined. This coefficient is then substituted into the above functional relationship to calculate the change in circulating flow, and finally, combined with the torque calculation formula, the degree of transmission torque attenuation can be deduced. This correlation model based on CFD analysis and function fitting provides a quantitative tool for guide wheel blade damage assessment and a theoretical basis for hydraulic system fault diagnosis and remaining life prediction. Simultaneously, this model can also guide the structural optimization design of guide wheel blades. By analyzing the sensitivity of different damage parameters to torque, reinforcement measures can be taken in areas of the blade prone to damage, such as increasing surface hardness or optimizing curvature distribution, to reduce the impact of micro-damage on transmission performance.

[0049] Specifically, the functional relationships between the different micro-damage characteristics and the circulating flow data include: The functional relationship between circulation flow rate and axial distance of micro-damage is shown in Equation 1 below: (1) In equation 1 above, A 1. A 2. A 3. A 4 represents the shape correlation coefficient, which is determined based on the geometry of the damage. d This represents the axial distance of the micro-damage.

[0050] Tables 1 to 3 below show the relevant data on the relationship between the circulation flow rate and the axial distance of the micro-damage in the fitting process of this embodiment:

[0051]

[0052]

[0053] Based on the data of circulation flow rate and axial distance of micro-damage in Tables 1 to 3 above, the shape correlation coefficients obtained after fitting are as follows: Cylinder: A 1 = -1.291e-10, A 2 = 1.055e-08, A 3 = -2.71e-07, A 4 = 0.005426.

[0054] Quadrilateral prism: A 1 = -6.032e-11, A 2 = 4.721e-09, A 3 = -1.846e-07, A 4 = 0.005425.

[0055] Triangular prism: A 1 = -2.416e-10, A 2 = 2.036e-08, A 3 = -5.353e-07, A 4 = 0.005426.

[0056] Substituting the shape correlation coefficients of the obtained cylinder, square prism and triangular prism into Equation 1 above, we can obtain the functional relationship between the circulation flow rate and the axial distance of the micro-damage under different geometric shapes.

[0057] Furthermore, the functional relationship between circulation flow rate and micro-damage height is shown in Equation 2 below: (2) In equation 2 above, P 1. P 2. P 3. P4 represents the shape correlation coefficient, which is determined based on the geometry of the damage. h This is the height of micro-damage.

[0058] Tables 1 to 3 below show the correlation data between circulation flow rate and micro-damage height in this embodiment:

[0059]

[0060]

[0061] Based on the data on circulation flow rate and micro-damage height from Tables 4 to 6 above, the shape correlation coefficients obtained after fitting are as follows: Cylinder: P 1 = -3.920e-02, P 2 = 4.396e-03, P 3 = -1.521e-04, P 4 = 5.423e-03.

[0062] Quadrilateral prism: P 1 = -2.009e-02, P 2 = 2.326e-03, P 3 = -9.625e-05, P 4 = 5.423e-03.

[0063] Triangular prism: P 1 = 4.727e-03, P 2 = -3.457e-04, P 3 = -3.452e-05, P 4 = 5.424e-03.

[0064] Substituting the shape correlation coefficients of the obtained cylinders, square prisms, and triangular prisms into equations 2 to 3 above, we can obtain the functional relationship between the circulation flow rate and the micro-damage height under different geometric shapes.

[0065] Furthermore, the functional relationship between the circulation flow rate and the micro-damage bottom surface size is shown in Equation 3 below: (3) In equation 3 above, C 1. C 2. C 3. C 4 is the shape correlation coefficient, which is determined according to the geometry of the damage, and s is the bottom dimension of the micro-damage, where it is the square of the bottom diameter for cylinders, and the square of the side length of the bottom for triangular and quadrangular prisms.

[0066] Tables 7 to 9 below show the relevant data on the circulation flow rate and the micro-damage bottom surface size in the fitting process of this embodiment:

[0067]

[0068]

[0069] Based on the data of circulation flow rate and micro-damage bottom surface size in Tables 7 to 9 above, the shape correlation coefficients obtained after fitting are as follows: Cylinder: C 1 = 7.469e-11, C 2 = -1.270e-08, C 3 = 5.533e-07, C 4 = 5.416e-03.

[0070] Quadrilateral prism: C 1 = -4.119e-10, C 2 = 3.910e-08, C 3 = -1.235e-06, C 4 = 5.434e-03.

[0071] Triangular prism: C 1 = 9.300e-11 C 2 = -1.140e-08 C 3 = 4.066e-07 C 4 = 5.418e-03.

[0072] Substituting the shape correlation coefficients of the obtained cylinders, square prisms, and triangular prisms into Equation 3 above, we can obtain the functional relationship between the circulating flow rate and the micro-damage bottom surface size under different geometric shapes.

[0073] Furthermore, the torque calculation formula is shown in Equation 4 below: (4) In equation 4 above: ρ For the working oil density, Q For circulating flow, R D2 The guide wheel exit radius, β D2 For the guide wheel exit angle, F D2 The cross-sectional area of ​​the guide wheel exit is... R T2 Where is the turbine outlet radius. β T2 For turbine outlet angle, FT2 The turbine outlet cross-sectional area, n T This refers to the turbine speed.

[0074] Furthermore, after substituting equations 1 to 3 above into the shape correlation coefficients for different geometric shapes, and classifying them by geometric shape, we combine them with equation 4 above to obtain the functional relationships between different micro-damage characteristic parameters and transmission torque, including: The functional relationship between transmission torque and axial distance of micro-damage is shown in Equation 5 below: (5) In equation 5 above, a 0、 a 1. a 2. a 3. a 4. a 5. a 6 is the shape correlation coefficient, determined based on the geometry of the damage. d This represents the axial distance of the micro-damage.

[0075] Based on the functional relationship between transmission torque and axial distance of micro-damage, this embodiment derives the following: Cylinder: a 0 = 4.663e-16 a 1 = -7.619e-14, a 2 = 5.071e-12, a 3 = 1.386e-08, a 4 = -1.147e-06, a 5 = 2.952e-05, a 6 = -1.414.

[0076] Quadrilateral prism: a 0 = 1.018e-16 a 1 = -1.593e-14, a 2 = 1.247e-12, a 3 = 6.520e-09, a 4 = -5.130e-07, a 5 = 2.010e-05, a 6 = -1.414.

[0077] Triangular prism: a 0 = 1.632e-15, a 1 = -2.752e-13 a 2 = 1.883e-11, a 3 = 2.570e-08, a 4 = -2.210e-06, a5 = 5.820e-05, a 6 = -1.414.

[0078] The functional relationship between transmission torque and micro-damage height is shown in Equation 6 below: (6) In equation 6 above, p 0、 p 1. p 2. p 3. p 4. p 5. p 6 is the shape correlation coefficient, determined based on the geometry of the damage. h This is the height of micro-damage.

[0079] Based on the functional relationship between transmission torque and micro-damage height, this embodiment derives the following: Cylinder: p 0 = 42.98922 p 1 = -9.64187 p 2 = 0.87407, p 3 = 4.23779 p 4 = -0.47918 p 5 = 0.01655 p 6 = -1.41388.

[0080] Quadrilateral prism: p 0 = 11.29139 p 1 = -2.61461, p 2 = 0.25956, p 3 = 2.17854 p 4 = -0.25328 p 5 = 0.010505, p6 = -1.41362.

[0081] Triangular prism: p 0 = 0.62511 p 1 = -0.09136 p 2 = -0.005787, p 3 = -0.51425 p 4 = 0.03768 p 5 = 0.00377 p 6 = -1.41393.

[0082] The functional relationship between transmission torque and the size of the micro-damaged bottom surface is shown in Equation 7 below: (7) In equation 7 above, c0、 c 1. c 2. c 3. c 4. c 5. c 6 is the shape correlation coefficient, determined based on the geometry of the damage. s The dimensions of the bottom surface with minimal damage.

[0083] Based on the functional relationship between transmission torque and the size of the micro-damaged bottom surface, this embodiment derives the following: Cylinder: c 0 = 1.561e-16 c 1 = -5.308e-14, c 2 = 6.824e-12, c 3 = -8.576e-09, c 4 = 1.400e-06, c 5 = -6.062e-05, c 6 = -1.413.

[0084] Quadrilateral prism: c 0 = 4.745e-15 c 1 = -9.011e-13, c 2 = 7.123e-11, c 3 = 4.190e-08, c 4 = -4.190e-06, c 5 = 1.339e-04, c 6 = -1.415.

[0085] Triangular prism: c 0 = 2.420e-16 c 1 = -5.932e-14, c 2 = 5.751e-12, c 3 = -1.043e-08, c 4 = 1.251e-06, c 5 = -4.450e-05, c 6 = -1.413.

[0086] Furthermore, by using equations 5-7 above, a quantitative correlation between different micro-damage characteristic parameters and transmission torque is obtained, providing a direct basis for the quantitative analysis of the impact of guide wheel blade damage on transmission performance. In practical engineering applications, by detecting specific parameters of micro-damage on the guide wheel blade surface, such as axial distance, height, and bottom dimensions, and combining them with its geometry to determine the corresponding shape correlation coefficient, the change in transmission torque can be calculated by substituting these parameters into the above functional relationship. This helps to realize the intelligent management transformation of guide wheel blades from passive maintenance to proactive early warning.

[0087] Please refer to the following: Figure 5 and Figure 6 The control device of this embodiment is based on the CFD analysis method for the impact of surface damage on transmission torque of the guide wheel blades. The device includes a mounting base 1, a heat-conducting base 2, a piezoelectric ceramic actuator 3, a strain gauge displacement sensor 4, a flexible metal diaphragm 5, and a control unit 6. The mounting base 1 is fitted into and fixedly connected to the groove of the guide wheel blade 7. The groove pre-drilled on the surface of the guide wheel blade 7 provides a stable positioning foundation for the mounting base 1, ensuring that the control device will not shift during operation. The flexible metal diaphragm 5 is disposed on the mounting base 1 and its outer surface is adapted to the surface of the guide wheel blade 7, forming a smoothly transitioning curved surface structure, avoiding further interference with the flow field distribution due to surface protrusions or depressions. The heat-conducting base 2 is fixed inside the mounting base 1 at the end away from the flexible metal diaphragm 5, which can quickly dissipate the heat generated by the piezoelectric ceramic actuator 3 during operation, preventing excessive temperature from affecting output accuracy and service life. The piezoelectric ceramic actuator 3 is disposed within the mounting base 1 and connected to the inner surface of the flexible metal diaphragm 5. By applying different voltage signals, it can generate precise micro-displacement drive, causing the flexible metal diaphragm 5 to undergo controllable elastic deformation, thereby dynamically compensating for micro-damage areas on the surface of the guide wheel blade 7. The strain gauge displacement sensor 4 is disposed within the mounting base 1 and cooperates with the flexible metal diaphragm 5 to monitor the deformation of the flexible metal diaphragm 5 in real time, providing accurate feedback data to the control unit 6.

[0088] Furthermore, the control unit 6 is electrically connected to both the piezoelectric ceramic actuator 3 and the strain gauge displacement sensor 4. The control unit 6 implements control based on a PID closed-loop control system. Please refer to [reference needed]. Figure 7 Its control process includes: S1. Set target damage characteristics: Based on the axial distance, height, and bottom dimension parameters of the micro-damage detected on the surface of the guide wheel blade 7, and combined with its geometry, determine the corresponding shape correlation coefficient, substitute it into the above functional relationship between transmission torque and micro-damage characteristic parameters, calculate the theoretical value of transmission torque under the current damage state, and use the flow field distribution characteristics corresponding to the theoretical value as the control target.

[0089] S2. Generating a piezoelectric drive signal based on error: The control unit 6 compares the actual deformation of the flexible metal diaphragm 5, which is collected in real time by the strain gauge displacement sensor 4, with the theoretical compensation deformation calculated based on the target damage characteristics to obtain the displacement error value. The error value is then subjected to proportional, integral, and derivative operations using a PID control algorithm to generate a corresponding voltage drive signal. The amplitude and frequency of this signal are dynamically adjusted according to the magnitude and trend of the error to ensure that the piezoelectric ceramic actuator 3 can output precise driving force.

[0090] S3. Displacement generated by the piezoelectric ceramic actuator: After receiving the voltage drive signal output by the control unit 6, the piezoelectric material inside the piezoelectric ceramic actuator 3 undergoes axial expansion and contraction deformation due to the inverse piezoelectric effect.

[0091] S4. Flexible Diaphragm Deformation: When the voltage signal is positive, the piezoelectric ceramic actuator 3 extends axially, pushing the flexible metal diaphragm 5 to bulge away from the mounting base 1, compensating for flow field depressions caused by pit-like damage on the surface of the guide wheel blade 7. Conversely, when the voltage signal is negative, the piezoelectric ceramic actuator 3 shortens axially, causing the flexible metal diaphragm 5 to contract towards the mounting base 1, counteracting flow field disturbances caused by protrusion-like damage. The response of the piezoelectric ceramic actuator 3 enables rapid tracking of flow field changes and dynamic compensation, ensuring accurate flow field control in micro-damaged areas and effectively reducing the adverse effects of micro-damage on circulating flow and transmission torque.

[0092] S5. Displacement sensor detects displacement: The strain gauge displacement sensor 4 is fitted to the inner surface of the flexible metal diaphragm 5 to sense its deformation. When the flexible metal diaphragm 5 is bent or stretched, the resistance value of its strain gauge changes accordingly. This change is converted into a voltage signal and transmitted to the control unit 6.

[0093] S6. Determine if the displacement error meets the requirements: The control unit 6 processes the voltage signal received in S5 to obtain the real-time displacement data of the flexible metal diaphragm 5, and compares it with the theoretical compensation deformation. If the requirements are not met, it returns to S2 to generate a new piezoelectric drive signal based on the error. If the requirements are met, it maintains the current drive signal, outputs the result, and completes one control cycle. Through the above PID closed-loop control process, a complete closed-loop feedback control is formed, thereby continuously optimizing the output of the piezoelectric ceramic actuator 3 and keeping the surface flow field of the guide wheel blade 7 within the target control range.

[0094] Specifically, the transfer function model of the piezoelectric ceramic actuator is established, as shown in Equation 8 below: (8) In equation 8 above,H ( x ) represents the transfer function model of the piezoelectric ceramic actuator. K h For system gain, ω h For natural frequency, ζ h For the damping ratio, x For Laplace variables.

[0095] Furthermore, the transfer function model of the strain gauge sensor is established, as shown in Equation 9 below: (9) In equation 9 above, L ( x ) represents the transfer function model of the strain gauge sensor. K l For system gain, T l It is a time constant. x For Laplace variables.

[0096] Furthermore, the transfer function model of the PID controller is established, as shown in Equation 10 below: (10) In the formula, G c ( x ( ) represents the transfer function model of a PID controller. K p This is the proportionality coefficient. K i The integral coefficient is... K d The differential coefficients are... x For Laplace variables.

[0097] Furthermore, the displacement output expression of the PID closed-loop control system is constructed as shown in Equation 11 below: (11) In equation 11 above, Y ( x () represents the actual displacement output. R ( x () represents the desired displacement output. G c ( x ( ) represents the transfer function model of a PID controller. H ( x ) represents the transfer function model of the piezoelectric ceramic actuator. L ( x ) represents the transfer function model of the strain gauge sensor.

[0098] By constructing the transfer function model using equations 8-11 above and establishing the displacement output expression of the PID control system, a precise mathematical description of the dynamic response process of the control device is achieved, providing theoretical support for system parameter optimization. By adjusting the proportional, integral, and derivative coefficients of the PID controller, the system can respond quickly and output stably under different operating conditions, effectively compensating for torque fluctuations caused by micro-damage to the guide wheel blades. Figure 8 The PID simulation control shown demonstrates that, through PID control adjustment, the target displacement and the actual displacement eventually become equal. The modular design of this control device facilitates installation and maintenance, and it is adaptable to different types of guide wheel blade structures, providing a reliable technical solution for dynamic compensation of guide wheel blade damage in engineering practice.

[0099] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0100] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A CFD analysis method for the effect of guide wheel blade surface damage on transmission torque, characterized in that: The analysis steps are as follows: Define micro-damage characteristics, including their distribution at different locations, shapes, and sizes on the surface of the guide vane blades; CFD preprocessing is performed to establish different guide wheel geometric models with micro-damage characteristics, and a single guide wheel flow channel is selected as the fluid computation domain. CFD calculation and post-processing: Based on the finite volume method, the selected guide wheel flow channel model is solved to obtain circulating flow data under different micro-damage characteristics; The functional relationship between different micro-damage characteristics and circulating flow data was obtained by fitting, and the functional relationship between different micro-damage characteristic parameters and transmission torque was established based on the torque calculation formula.

2. The CFD analysis method for the effect of guide wheel blade surface damage on transmission torque as described in claim 1, characterized in that: The different locations are defined as the different axial distances at which the micro-damage is located at the inlet of the guide wheel blade; the different shapes are defined as structural protrusions or pits on the working surface of the guide wheel flow channel model, including cylindrical, triangular prism and quadrangular prism shapes.

3. The CFD analysis method for the effect of guide wheel blade surface damage on transmission torque as described in claim 1, characterized in that: The different sizes are defined as follows: For protrusions or depressions in cylindrical structures, the micro-damage characteristic parameters are the diameter and height of the cylinder's base. For protrusions or depressions in a triangular prism structure, the micro-damage characteristic parameters are the side length and height of the base of the triangular prism. For protrusions or depressions in a quadrangular prism structure, the micro-damage characteristic parameters are the side length and height of the base of the quadrangular prism.

4. The CFD analysis method for the effect of guide wheel blade surface damage on transmission torque as described in claim 1, characterized in that: The selected guide wheel flow channel model includes the inlet face, outlet face, working face, non-working face, inner ring face, and outer ring face.

5. The CFD analysis method for the effect of guide wheel blade surface damage on transmission torque as described in claim 1, characterized in that: The selection of a single guide wheel channel as the fluid computation domain includes the following steps: A guide wheel flow channel mesh model was established based on hexahedral unstructured mesh generation; Assign fluid physical properties to the mesh model, set the turbulence model, and set boundary conditions.

6. The CFD analysis method for the effect of guide wheel blade surface damage on transmission torque as described in claim 1, characterized in that: The functional relationships between different micro-damage characteristics and circulating flow data include: The functional relationship between circulation flow rate and axial distance of micro-damage is shown in the following formula: In the formula, A 1. A 2. A 3. A 4 represents the shape correlation coefficient, which is determined based on the geometry of the damage. d This represents the axial distance of the micro-damage. The functional relationship between circulation flow rate and micro-damage height is shown in the following equation: In the formula, P 1. P 2. P 3. P 4 represents the shape correlation coefficient, which is determined based on the geometry of the damage. h The height of the micro-damage; The functional relationship between the circulation flow rate and the micro-damaged bottom surface size is shown in the following equation: In the formula, C 1. C 2. C 3. C 4 represents the shape correlation coefficient, which is determined based on the geometry of the damage. s The dimensions of the bottom surface with minimal damage.

7. The CFD analysis method for the effect of guide wheel blade surface damage on transmission torque as described in claim 1, characterized in that: The torque calculation formula is shown below: In the formula: ρ For the working oil density, Q For circulating flow, R D2 The guide wheel exit radius, β D2 For the guide wheel exit angle, F D2 The cross-sectional area of ​​the guide wheel exit is... R T2 Where is the turbine outlet radius. β T2 For turbine outlet angle, F T2 The turbine outlet cross-sectional area, n T This refers to the turbine speed.

8. The CFD analysis method for the effect of guide wheel blade surface damage on transmission torque as described in claim 1, characterized in that: The functional relationships between different micro-damage characteristic parameters and transmission torque include: The functional relationship between transmission torque and axial distance of micro-damage is shown in the following formula: In the formula, a 0、 a 1. a 2. a 3. a 4. a 5. a 6 is the shape correlation coefficient, determined based on the geometry of the damage. d This represents the axial distance of the micro-damage. The functional relationship between transmission torque and micro-damage height is shown in the following equation: In the formula, p 0、 p 1. p 2. p 3. p 4. p 5. p 6 is the shape correlation coefficient, determined based on the geometry of the damage. h The height of the micro-damage; The functional relationship between transmission torque and the size of the micro-damaged bottom surface is shown in the following formula: In the formula, c 0、 c 1. c 2. c 3. c 4. c 5. c 6 is the shape correlation coefficient, determined based on the geometry of the damage. s The dimensions of the bottom surface with minimal damage.

9. A control device, said control device being based on the CFD analysis method for the effect of guide wheel blade surface damage on transmission torque as described in any one of claims 1 to 8, characterized in that: The device includes a mounting base (1), a thermally conductive base (2), a piezoelectric ceramic actuator (3), a strain gauge displacement sensor (4), a flexible metal diaphragm (5), and a control unit (6). The mounting base (1) is fitted into the groove of the guide wheel blade (7) and fixedly connected. The flexible metal diaphragm (5) is disposed on the mounting base (1) and its outer surface is adapted to the surface of the guide wheel blade (7). The thermally conductive base (2) is fixed in the mounting base (1) at one end away from the flexible metal diaphragm (5). The piezoelectric ceramic actuator (3) is disposed in the mounting base (1) and fixed to the inner surface of the flexible metal diaphragm (5). The strain gauge displacement sensor (4) is disposed in the mounting base (1) and fits into the flexible metal diaphragm (5).

10. The control device as described in claim 9, characterized in that: The control unit (6) is electrically coupled to the piezoelectric ceramic actuator (3) and the strain gauge displacement sensor (4); the control unit (6) acts on the control device based on the PID control system.

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