A fluid-solid coupling method and device for vibration analysis of a hydropower station powerhouse

Abstract

This invention relates to the field of vibration analysis technology for hydropower plant buildings, and discloses a fluid-structure interaction method and apparatus for vibration analysis of hydropower plant buildings. The method includes: constructing and solving a CFD model of the turbine flow channels of the target hydropower plant building to obtain transient flow field data; constructing a three-dimensional finite element model of the plant structure; wherein the three-dimensional finite element model of the plant structure is consistent with the turbine flow channel partitions in the CFD model of the turbine flow channels of the target hydropower plant building; interpolating and mapping the transient flow field data to the three-dimensional finite element model of the plant structure to obtain a pressure distribution sequence in the finite element region; performing consistency verification and local correction processing on the pressure distribution sequence in the finite element region to obtain a pressure distribution sequence at the finite element nodes; and performing transient structural dynamic response analysis based on the pressure distribution sequence at the finite element nodes to obtain the vibration analysis results of the target hydropower plant building. This invention significantly improves the accuracy and reliability of vibration analysis of hydropower plant buildings.

Description

Technical Field

[0001] This invention relates to the field of vibration analysis technology for hydropower plant buildings, specifically to a fluid-structure interaction method and apparatus for vibration analysis of hydropower plant buildings. Background Technology

[0002] With the increasing output and size of single turbine units in hydropower stations, especially the continuous improvement of operating head and speed in pumped storage power stations, the problems of hydraulic stability of the units and vibration of the powerhouse structure have become increasingly prominent. Among them, the vibration of the powerhouse is mainly affected by hydraulic vibration sources, mechanical vibration sources and electromagnetic vibration sources, with hydraulic vibration sources usually playing a dominant role.

[0003] The existing methods for analyzing plant vibration lack systematic mapping and coupling analysis of data from multiple sources, regions, and time steps, making it difficult for vibration analysis results to accurately reflect the stress state of the plant. Summary of the Invention

[0004] This invention provides a fluid-structure interaction method and apparatus for vibration analysis of hydropower plant buildings, in order to solve the problem that the vibration analysis results of power plant buildings are difficult to accurately reflect the stress state of the power plant buildings.

[0005] In a first aspect, the present invention provides a fluid-structure interaction method for vibration analysis of hydropower plant buildings, the method comprising: Construct and solve the CFD model of the unit flow channel of the target hydropower station powerhouse to obtain transient flow field data; A three-dimensional finite element model of the powerhouse structure is constructed; wherein, the three-dimensional finite element model of the powerhouse structure is consistent with the unit flow channel partitioning in the CFD model of the unit flow channel of the target hydropower station powerhouse. Transient flow field data is interpolated and mapped onto a three-dimensional finite element model of the plant structure to obtain the pressure distribution sequence in the finite element region. Consistency verification and local correction are performed on the pressure distribution sequence of the finite element region to obtain the pressure distribution sequence of the finite element nodes. Transient structural dynamic response analysis was performed based on the finite element nodal pressure distribution sequence, and the vibration analysis results of the target hydropower station powerhouse were obtained.

[0006] This invention provides a fluid-structure interaction (FSI) method for vibration analysis of hydropower plant buildings. It constructs a three-dimensional finite element model of the plant structure that is consistent with the unit flow channel partitions in the CFD model of the target hydropower plant's unit flow channels. Interpolation mapping is used to achieve systematic coupling of transient flow field data from multiple sources, regions, and time steps to the structural model. Leveraging the advantage of CFD simulation data in fully revealing the spatiotemporal characteristics of hydraulic pulsations, and considering the spatial distribution characteristics of pressure within the volute, it more realistically reflects the hydraulic vibration sources of the plant. Simultaneously, by performing consistency verification and local correction processing on the pressure distribution sequence of the finite element region, the reliability of data transmission is fully guaranteed, ensuring the validity of the finite element node pressure distribution sequence. Furthermore, transient structural dynamic response analysis is performed based on the finite element node pressure distribution sequence, significantly improving the accuracy and reliability of hydropower plant vibration analysis and accurately reflecting the stress state of the plant.

[0007] In one optional implementation, transient flow field data is interpolated and mapped onto a three-dimensional finite element model of the plant structure to obtain a pressure distribution sequence in the finite element region, including: For each finite element node in the three-dimensional finite element model of the factory structure, a spatial interpolation neighborhood is constructed, and based on transient flow field data, multiple CFD flow field nodes are searched within the spatial interpolation neighborhood as CFD reference points. Construct the kernel function; For each finite element node, based on the CFD reference point, interpolation is performed using a kernel function to obtain the pressure data of each finite element node; Based on the pressure data of each finite element node, a pressure distribution sequence of the finite element region is generated step by step over time.

[0008] This invention provides a fluid-structure interaction method for vibration analysis of hydropower plant buildings. By constructing a spatial interpolation neighborhood and using kernel function-based interpolation, it achieves accurate spatial mapping of transient flow field data to a three-dimensional finite element model of the plant structure, and generates a complete pressure distribution sequence step by step. This method fully preserves the spatial pressure distribution characteristics of flow channel regions such as the volute, and solves the problem of vibration analysis distortion caused by neglecting spatial distribution in the single-point extrapolation method.

[0009] In one optional implementation, for each finite element node, interpolation is performed using a kernel function based on a CFD reference point to obtain the pressure data for each finite element node, including: the kernel function being a radial basis function. Based on the spatial distance between finite element nodes and CFD reference points, a radial basis function matrix is ​​constructed using radial basis functions. Establish a system of linear equations based on the radial basis function matrix; The linear equations are solved based on the transient flow field data corresponding to the CFD reference point to obtain the interpolation weighting coefficients. The pressure data of each finite element node are calculated based on the interpolation weighting coefficients and the radial basis function matrix.

[0010] This invention provides a fluid-structure interaction method for vibration analysis of hydropower plant buildings. It constructs a radial basis function matrix and establishes a system of linear equations by using the spatial distance between finite element nodes and CFD reference points. Based on the transient flow field data corresponding to the CFD reference points, it solves the interpolation weighting coefficients and finally obtains the pressure at the finite element nodes by weighting. It does not require CFD and FEA mesh matching, the interpolation strictly passes through the reference points, the numerical calculation is stable, the pressure field is continuous and smooth, and it can accurately restore the spatial distribution characteristics of pressure in areas such as the volute, significantly improving the load mapping accuracy.

[0011] In one optional implementation, for each finite element node, interpolation is performed using a kernel function based on a CFD reference point to obtain the pressure data for each finite element node. This includes using an inverse distance weighting function as the kernel function. Based on the spatial distance between finite element nodes and CFD reference points, the original weights of CFD reference points are calculated using the inverse distance weighting function. The original weights of the CFD reference points are normalized to obtain normalized weights. By using normalized weights, the transient flow field data corresponding to the CFD reference point are weighted and summed to obtain the pressure data of each finite element node.

[0012] This invention provides a fluid-structure interaction method for vibration analysis of hydropower plant buildings. Based on the spatial distance between finite element nodes and CFD reference points, the method uses an inverse distance weighting function to calculate and normalize the original weights. The pressure at the finite element nodes is obtained by weighted summation, which can quickly achieve accurate mapping of flow field pressure to the structural model, ensure smooth and continuous pressure distribution, and effectively improve the accuracy of load input.

[0013] In one optional implementation, the pressure distribution sequence of the finite element region is subjected to consistency verification and local correction processing to obtain the pressure distribution sequence of the finite element nodes, including: Pre-check the mapping data of the pressure distribution sequence in the finite element region; If the pre-check results of the mapping data meet the preset mapping conditions, then the consistency judgment index of each finite element node is calculated based on the pressure distribution sequence of the finite element region; among which, the consistency judgment index includes the spatial matching error index, the data smoothness index and the reference consistency error index. The consistency judgment index is compared with the preset threshold, and the pressure distribution sequence of the finite element region is locally corrected based on the comparison result to obtain the pressure distribution sequence of the finite element nodes.

[0014] This invention provides a fluid-structure interaction method for vibration analysis of hydropower plant buildings. It pre-checks the mapping data of the pressure distribution sequence in the finite element region, filtering out invalid mapping data in advance to avoid interference from invalid data in subsequent analysis, reducing the workload of local corrections, and improving overall process efficiency. Then, based on the pressure distribution sequence of the finite element region, it calculates the consistency judgment index of each finite element node, quantitatively verifying the quality of the pressure distribution sequence from multiple dimensions. Based on the comparison results of the consistency judgment index and preset thresholds, it performs local corrections on the pressure distribution sequence of the finite element region, avoiding full-domain recalculation, specifically addressing abnormal area problems, ensuring the reliability and rationality of the pressure distribution sequence of the finite element nodes, and providing high-quality load input for subsequent structural vibration analysis.

[0015] In one optional implementation, transient structural dynamic response analysis is performed based on the finite element nodal pressure distribution sequence to obtain the vibration analysis results of the target hydropower station powerhouse, including: Based on the time step matching relationship between finite element nodes and CFD flow field nodes, the pressure distribution sequence of finite element nodes is synchronously extracted to obtain the node pressure data corresponding to the finite element time step. The nodal pressure data corresponding to the finite element time step are used as surface pressure loads and applied to the unit flow channel region in the three-dimensional finite element model of the powerhouse structure. Transient structural dynamic response analysis is then performed to obtain the vibration analysis results of the target hydropower station powerhouse.

[0016] This invention provides a fluid-structure interaction (FSI) method for vibration analysis of hydropower plant buildings. By synchronously extracting the pressure distribution sequence of finite element nodes according to the time step matching relationship between finite element nodes and CFD flow field nodes, it ensures complete alignment between the CFD transient pressure and the FEA dynamic analysis time domain. This achieves precise synchronization of the FSI time domain, avoiding excitation distortion caused by timing misalignment, and accurately reflects the time-varying characteristics of hydraulic pulsations. It also preserves the amplitude and frequency characteristics of the original flow field pressure pulsations to the maximum extent. Furthermore, the node pressure data corresponding to the finite element time step is used as a surface pressure load and applied to the unit flow channel region in the three-dimensional finite element model of the power plant structure. Transient structural dynamic response analysis is then performed, accurately reflecting the dynamic characteristics of the hydropower plant under complex hydraulic pulsations, significantly improving the accuracy and engineering applicability of the vibration analysis results.

[0017] Secondly, the present invention provides a fluid-structure interaction device for vibration analysis of hydropower plant buildings, the device comprising: The solver module is used to construct and solve the CFD model of the unit flow channel of the target hydropower station powerhouse to obtain transient flow field data; The construction module is used to build a three-dimensional finite element model of the powerhouse structure; wherein, the three-dimensional finite element model of the powerhouse structure is consistent with the unit flow channel partition in the CFD model of the unit flow channel of the target hydropower station powerhouse; The mapping module is used to interpolate and map transient flow field data onto a three-dimensional finite element model of the plant structure to obtain the pressure distribution sequence in the finite element region. The correction module is used to perform consistency verification and local correction processing on the pressure distribution sequence of the finite element region to obtain the pressure distribution sequence of the finite element nodes. The analysis module is used to perform transient structural dynamic response analysis based on the finite element nodal pressure distribution sequence, and obtain the vibration analysis results of the target hydropower plant.

[0018] Thirdly, the present invention provides an electronic device, comprising: a memory and a processor, wherein the memory and the processor are communicatively connected to each other, the memory stores computer instructions, and the processor executes the computer instructions to perform the fluid-structure interaction method for vibration analysis of hydropower plant buildings described in the first aspect or any corresponding embodiment.

[0019] Fourthly, the present invention provides a computer-readable storage medium storing computer instructions for causing a computer to execute the fluid-structure interaction method for vibration analysis of a hydropower plant as described in the first aspect or any corresponding embodiment above.

[0020] Fifthly, the present invention provides a computer program product, including computer instructions for causing a computer to execute the fluid-structure interaction method for vibration analysis of hydropower plant buildings described in the first aspect or any corresponding embodiment. Attached Figure Description

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

[0022] Figure 1 This is a schematic diagram of an application scenario according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the first flow of a fluid-structure interaction method for vibration analysis of a hydropower plant, according to an embodiment of the present invention. Figure 3 This is a schematic diagram of the CFD model of the unit flow channel of the target hydropower plant according to an embodiment of the present invention; Figure 4 This is a schematic diagram of the flow channel model in the three-dimensional finite element model of the factory structure according to an embodiment of the present invention; Figure 5This is a schematic diagram of a second flow of a fluid-structure interaction method for vibration analysis of a hydropower plant, according to an embodiment of the present invention. Figure 6 This is a schematic diagram of the third flow of a fluid-structure interaction method for vibration analysis of a hydropower plant, according to an embodiment of the present invention. Figure 7 This is a schematic diagram of the fourth flow of a fluid-structure interaction method for vibration analysis of a hydropower plant, according to an embodiment of the present invention. Figure 8 This is a structural block diagram of a fluid-structure interaction device for vibration analysis of a hydropower plant, according to an embodiment of the present invention. Figure 9 This is a schematic diagram of the hardware structure of an electronic device according to an embodiment of the present invention. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] It is understood that before using the technical solutions disclosed in the various embodiments of the present invention, users should be informed of the types, scope of use, and usage scenarios of the personal information involved in the present invention and their authorization should be obtained in accordance with relevant laws and regulations through appropriate means.

[0025] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0026] As an optional application scenario of this invention, such as Figure 1 As shown, the fluid-structure interaction system for vibration analysis of hydropower plant buildings may include at least one terminal device and at least one server. Figure 1 The system is illustrated in the example, which includes a computer 101, a mobile terminal 102, and a server 103, and the terminal devices such as the computer 101 and the mobile terminal 102 are connected to the server 103 through a network 110.

[0027] Specifically, the terminal device can be a smartphone, tablet, laptop, PDA, desktop computer, game console, smart TV, smart wearable device, in-vehicle terminal, VR (Virtual Reality) device, AR (Augmented Reality) device, etc. Server 103 can be a standalone physical server, a server cluster, a distributed system, or a cloud server providing cloud services. Network 110 can be a wired or wireless network, examples of which include, but are not limited to, the Internet, corporate intranet, local area network, wide area network, mobile communication network, and combinations thereof.

[0028] In the process of vibration analysis of related factory buildings, the volute is not only the main place where hydraulic vibration sources occur and the carrier of pulsating pressure, but also the key path for the transmission of hydraulic vibration sources to the factory building structure. Its internal flow field and pressure pulsation directly determine the intensity, frequency and spatial distribution of hydraulic vibration sources, and is the core related link of hydraulic vibration of factory buildings.

[0029] When calculating plant vibration, hydraulic vibration sources are often simplified by using a limited number of measuring points. That is, the complex pulsating pressure inside the volute is often simplified. For example, a measuring point is set only at the inlet of the volute, and the pressure at that point is extrapolated to the entire volute. This method ignores the spatial distribution characteristics of the pressure inside the volute, which causes the vibration analysis results to deviate from the actual situation and makes it difficult to accurately reflect the stress state of the plant.

[0030] Furthermore, the relevant plant vibration analysis technology lacks a method for systematically mapping and coupling analysis of data from multiple sources, regions, and time steps, and also lacks a consistency verification mechanism.

[0031] This invention provides a fluid-structure interaction method for vibration analysis of hydropower plant buildings. By making full use of CFD simulation data, it can fully reveal the advantages of the spatiotemporal characteristics of hydraulic pulsation. It also considers the spatial distribution characteristics of pressure inside the volute, thus more realistically reflecting the hydraulic vibration source of the power plant. At the same time, it adds an interpolation data consistency verification mechanism to fully ensure the reliability of data transmission.

[0032] According to an embodiment of the present invention, a fluid-structure interaction method for vibration analysis of hydropower plant buildings is provided. It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. Furthermore, although a logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in a different order than that shown here.

[0033] This embodiment provides a fluid-structure interaction method for vibration analysis of hydropower plant buildings, which can be used in the aforementioned terminal equipment. Figure 2This is a flowchart of a fluid-structure interaction method for vibration analysis of hydropower plant buildings according to an embodiment of the present invention, as shown below. Figure 2 As shown, the process includes the following steps: Step S201: Construct and solve the CFD model of the unit flow channel of the target hydropower station powerhouse to obtain transient flow field data.

[0034] Specifically, based on the design drawings such as the single-line diagram of the unit flow channels in the target hydropower plant, a CFD (Computational Fluid Dynamics) model of the unit flow channels in the hydropower plant is created.

[0035] Furthermore, due to the gap between the upper crown and lower ring of the runner, the gap cavity of the upper crown is connected to the draft tube through the equalizing pipe, which plays a role in equalizing pressure and stabilizing flow. To maximize the calculation accuracy, the CFD model of the unit flow channel of the target hydropower plant should include detailed structures such as the volute A, runner, movable guide vanes, fixed guide vanes, equalizing pipe B, and draft tube C. The computational domain of each part can be meshed using commonly used CFD meshing software (such as ICEM). The volute, fixed guide vanes, movable guide vanes, runner, gap, equalizing pipe, and draft tube all use a hexahedral mesh structure to achieve higher computational quality. The CFD model of the unit flow channel of the target hydropower plant is as follows: Figure 3 As shown.

[0036] Furthermore, the aforementioned volute, fixed guide vane, movable guide vane, impeller, clearance, equalizing pipe, and tailrace pipe are key components that significantly contribute to the pulsating pressure of the flow field and have a significant impact on the vibration analysis results of the plant. Therefore, a hexahedral mesh structure is preferred to improve the accuracy of numerical calculations. For other components or auxiliary flow channel structures with more complex geometries and relatively smaller contributions to fluid-structure interaction excitation, tetrahedral meshes, prismatic meshes, or hexahedral-tetrahedral hybrid meshes can be used for meshing according to specific geometric characteristics. Boundary layer meshes are set in the near-wall region to meet the accuracy requirements. This embodiment of the invention does not limit the specific mesh type for non-critical components, and the meshing method does not affect the implementation effect of the fluid-structure interaction method of this invention.

[0037] Since the opening of the movable guide vane needs to be adjusted for different working conditions, it is necessary to specify the boundary motion of the dynamic mesh model, that is, the description of the closing or opening law of the guide vane. The motion of the movable guide vane can be regarded as a rigid body rotating around a fixed axis. Each movable guide vane is regarded as a rigid body, and each performs the same rotational motion along its own mounting axis. The axis position of each blade can be read from the drawing.

[0038] The flow domain of the active guide vane is based on tetrahedral and prism layer mesh elements. During the dynamic mesh simulation, in order to ensure the stability of the boundary layer mesh, the node coordinates of each element in the boundary layer region are updated in the same way as the displacement of the corresponding node on the reference plane. The opening or closing of the active guide vane is controlled by the mesh reconstruction method. For example, the boundary layer thickness can be set to 12 mm, containing 7 mesh nodes. When the mesh skewness exceeds 0.85 or the length scale falls below 6 mm or above 70 mm, the mesh of the active guide vane can be regenerated.

[0039] Furthermore, before performing CFD flow field solution on the CFD model of the turbine flow channel of the target hydropower plant, the following boundary conditions need to be set: Turbine inlet conditions: pressure inlet conditions are adopted, i.e., at the volute inlet, the relative total pressure is given according to the turbine head, and the flow direction is perpendicular to the volute inlet section; Turbine outlet conditions: pressure outlet conditions are adopted, i.e., at the tailrace outlet, the average static pressure is given; Pump inlet conditions: flow inlet conditions are adopted, i.e., at the intake pipe inlet, the pump flow rate is given, and the flow direction is perpendicular to the inlet section; Pump outlet conditions: pressure outlet conditions are adopted, i.e., at the volute outlet, the average static pressure is given; Runner speed... The parameters are given based on the turbine speed; wall conditions: the solid wall adopts a no-slip boundary condition; interface: a slip mesh model is used in the calculation to simulate the dynamic and static interference flow field. The mesh of the runner component rotates relative to the mesh of the movable guide vane and the draft tube component. The mesh nodes on both sides of the interface do not overlap; the calculation of each component is performed simultaneously; and at the interface, the velocity component and turbulent flow rate are consistent after interpolation, and the pressure and flow flux are consistent after integration; the interface between the volute and the fixed guide vane, and the interface between the fixed guide vane and the movable guide vane adopt the stage (a data structure) type interface, while the interface between the movable guide vane and the runner, and the interface between the runner and the draft tube are slip interfaces.

[0040] Furthermore, firstly, steady flow calculations are performed on the CFD model of the unit flow channel of the target hydropower plant, and the converged flow field data is used as the initial field. Then, unsteady numerical calculations are performed on the CFD model of the unit flow channel of the target hydropower plant under steady-state conditions (i.e., unsteady flow numerical calculations are performed under steady-state conditions) to obtain the transient pressure distribution and transient velocity distribution of the entire flow channel at each moment, that is, the transient hydrodynamic characteristics under different operating conditions. The pressure distribution, velocity distribution and other parameters in the flow field are obtained through simulation, which provide input loads for subsequent finite element vibration analysis. The CFD software (Fluent, etc.) is used to output the node information file in partitions. The file should contain the node number and the x, y, z coordinates of the node, as well as the dynamic characteristic results (pressure distribution, velocity distribution, etc.).

[0041] Among them, the unsteady values ​​under steady-state conditions use the full flow channel data after the steady-state calculation converges as the initial conditions for calculation. The time step of the unsteady analysis is 1 / 200 of the rotor rotation period T. One data is saved for each calculation step, that is, the data sampling period is △T=T / 200.

[0042] Step S202: Construct a three-dimensional finite element model of the powerhouse structure; wherein, the three-dimensional finite element model of the powerhouse structure is consistent with the unit flow channel partitioning in the CFD model of the unit flow channel of the target hydropower station powerhouse.

[0043] Specifically, based on the design drawings, a three-dimensional finite element model of the plant structure was created. This calculation model includes the unit flow channels (tailwater pipe, volute, etc.) and the surrounding concrete, machine blocks, wind hoods, floor slabs, plant side walls, structural columns, and other local structures. The stairs and some openings were simulated in full size. The concrete structure was basically all made of hexahedral block elements, which effectively simulated the real stiffness of the actual floor slabs and beam structures.

[0044] In particular, the flow channel partitions in the 3D finite element model of the powerhouse structure are consistent with the CFD model partitions of the flow channels in the target hydropower station powerhouse, so as to map the CFD calculation results of the corresponding regions to the nodes of the finite element model. The flow channel model in the 3D finite element model of the powerhouse structure is as follows: Figure 4 As shown; for example, the flow channel partitions of the unit include: such as the volute area SP, the fixed guide vane area SV, the movable guide vane area GV, the cover plate and bottom ring area GAP, the tailrace pipe area DT, etc.

[0045] Furthermore, use finite element software (ANSYS, etc.) or modeling software to output the node information file of the three-dimensional finite element model of the plant structure. This file should include the node number and the x, y, and z coordinates of each node.

[0046] Step S203: The transient flow field data is interpolated and mapped to the three-dimensional finite element model of the plant structure to obtain the pressure distribution sequence of the finite element region.

[0047] Specifically, various interpolation methods can be used, including nearest neighbor interpolation, inverse distance weighting, and radial basis function interpolation (RBF), to realize the pressure mapping from CFD flow field nodes to FEA (Finite Element Analysis) structural nodes in space. In each time step, interpolation calculations are performed on the FEA nodes to generate the corresponding node values.

[0048] Step S204: Perform consistency verification and local correction on the pressure distribution sequence of the finite element region to obtain the pressure distribution sequence of the finite element nodes.

[0049] Step S205: Perform transient structural dynamic response analysis based on the finite element nodal pressure distribution sequence to obtain the vibration analysis results of the target hydropower station powerhouse.

[0050] Specifically, after completing the spatial interpolation from CFD to FEA, the transient fluid pressure is applied sequentially to the three-dimensional finite element model of the plant structure according to time steps using a time-domain synchronization method to obtain the dynamic response of the structure under real fluid loads.

[0051] This embodiment provides a fluid-structure interaction (FSI) method for vibration analysis of hydropower plant buildings. It constructs a three-dimensional finite element model of the plant structure that is consistent with the unit flow channel partitions in the CFD model of the target hydropower plant's unit flow channels. Interpolation mapping is used to achieve systematic coupling of transient flow field data from multiple sources, regions, and time steps to the structural model. Leveraging the advantage of CFD simulation data in fully revealing the spatiotemporal characteristics of hydraulic pulsations, and considering the spatial distribution characteristics of pressure within the volute, it more realistically reflects the hydraulic vibration sources of the plant. Simultaneously, by performing consistency verification and local correction processing on the pressure distribution sequence of the finite element region, the reliability of data transmission is fully guaranteed, ensuring the validity of the finite element node pressure distribution sequence. Furthermore, transient structural dynamic response analysis is performed based on the finite element node pressure distribution sequence, significantly improving the accuracy and reliability of hydropower plant vibration analysis and accurately reflecting the stress state of the plant.

[0052] This embodiment provides a fluid-structure interaction method for vibration analysis of hydropower plant buildings, which can be used in the aforementioned terminal equipment. Figure 5 This is a flowchart of a fluid-structure interaction method for vibration analysis of hydropower plant buildings according to an embodiment of the present invention, as shown below. Figure 5 As shown, the process includes the following steps: Step S501: Construct and solve the CFD model of the unit flow channels in the target hydropower station powerhouse to obtain transient flow field data. For details, please refer to [link to relevant documentation]. Figure 2 Step S201 of the illustrated embodiment will not be described again here.

[0053] Step S502: Construct a three-dimensional finite element model of the powerhouse structure; wherein, the three-dimensional finite element model of the powerhouse structure is consistent with the unit flow channel partitioning in the CFD model of the unit flow channel of the target hydropower station powerhouse. For details, please refer to... Figure 2 Step S202 of the illustrated embodiment will not be described again here.

[0054] Step S503: The transient flow field data is interpolated and mapped to the three-dimensional finite element model of the plant structure to obtain the pressure distribution sequence of the finite element region.

[0055] Specifically, step S503 includes: Step S5031: Construct a spatial interpolation neighborhood for each finite element node in the three-dimensional finite element model of the plant structure, and search for multiple CFD flow field nodes within the spatial interpolation neighborhood as CFD reference points based on transient flow field data.

[0056] Specifically, a spatial interpolation neighborhood of a certain radius is established for each FEA node (i.e., finite element node), and several CFD flow field nodes are searched within this spatial interpolation neighborhood as interpolation reference points (i.e., CFD reference points).

[0057] The spatial interpolation neighborhood radius is not a fixed value, but is adaptively set according to the CFD calculation grid scale. The spatial interpolation neighborhood radius can be 1 to 5 times the feature size of the CFD neighboring grid, preferably 2 to 3 times. Furthermore, when constructing the interpolation neighborhood, priority is given to ensuring that the interpolation neighborhood of each finite element node contains no less than the preset minimum number (e.g., 3) and no more than the maximum number (e.g., 10) of CFD reference points. When the number of reference nodes is insufficient, the spatial interpolation neighborhood radius can be automatically increased until the interpolation calculation requirements are met.

[0058] Step S5032: Construct the kernel function.

[0059] Specifically, the weight function or kernel function is automatically constructed based on the selected method.

[0060] Furthermore, for scenarios with complex pressure spatial distribution and high requirements for interpolation smoothness (such as the volute tongue region and high-pulsation regions), a radial basis function interpolation method is adopted. This method uses the Euclidean distance between the finite element node and its neighboring CFD reference point as the independent variable to construct the radial basis function kernel function. Here, it is assumed that the coordinates of the target finite element node are... , No. The coordinates of the CFD reference points are: The Euclidean distance between the two for: (1) Furthermore, when using Gaussian radial basis functions, its kernel function... It can be represented as: (2) In the above formula, The shape parameter controls the rate at which the kernel function decays with distance. Its value can be determined based on the average spacing of the CFD reference points in the neighborhood, the neighborhood radius, or empirical parameters, thereby achieving a balance between interpolation accuracy and numerical stability.

[0061] When using polynomial radial basis functions, an approximate description of the spatial distribution trend is achieved by constructing a polynomial function that monotonically varies with the distance between nodes. (Kernel function) It can be represented as: (3) In the above formula, A translation constant introduced to prevent numerical singularities when the distance approaches zero; The order of the polynomial is used to control the smoothness of the interpolation function.

[0062] Furthermore, for scenarios with large-scale grids and high computational efficiency requirements, the method is computationally simple and numerically stable. It employs the Inverse Distance Weighted (IDW) interpolation method, preferably using the inverse square of the distance to construct the weight function, whose expression is: (4) In the above formula, Indicates the first The original weights of the CFD reference points.

[0063] The aforementioned weight function form can effectively enhance the influence of nearest neighbor nodes on the interpolation results while maintaining computational simplicity and suppressing errors introduced by distant nodes.

[0064] Step S5033: For each finite element node, based on the CFD reference point, interpolation is performed using a kernel function to obtain the pressure data of each finite element node.

[0065] Specifically, for each FEA node, based on the spatial location and pressure value of the CFD reference point in its neighborhood, the interpolation equations are solved to obtain the target node pressure, i.e., the pressure data of each finite element node.

[0066] In some optional implementations, step S5033 includes: Step a1: Based on the spatial distance between the finite element nodes and the CFD reference point, construct the radial basis function matrix using radial basis functions. .

[0067] Specifically, in the radial basis function interpolation process, the radial basis function matrix is ​​constructed by the distance between the finite element node and the CFD reference point in the neighborhood. That is, the spatial distance between the finite element node and the CFD reference point is substituted into the above formula (2) or formula (3) to obtain the generated radial basis function matrix.

[0068] Step a2: Establish a system of linear equations based on the radial basis function matrix.

[0069] Specifically, the system of linear equations can be expressed as: (5) In the above formula, Indicates the interpolation weight coefficients. This represents the nodal pressure in the transient flow field data corresponding to the CFD reference point.

[0070] Step a3: Solve the linear equations based on the transient flow field data corresponding to the CFD reference point to obtain the interpolation weighting coefficients.

[0071] Specifically, the physical quantities at the CFD reference point (i.e., the nodal pressures at the CFD reference point) are taken as known conditions and substituted into the above formula (5) to solve the corresponding linear equation system and obtain the interpolation weighting coefficients for each CFD reference point. The interpolation weighting coefficients are used to calculate the physical quantities at the nodes of the target finite element.

[0072] Step a4: Calculate the pressure data of each finite element node based on the interpolation weighting coefficients and the radial basis function matrix.

[0073] Specifically, using interpolation weight coefficients The pressure data of each finite element node are obtained by weighted summation of the kernel function values ​​in the radial basis function matrix.

[0074] In the above optional implementation, a radial basis function matrix is ​​constructed by the spatial distance between the finite element nodes and the CFD reference point, and a system of linear equations is established. The interpolation weighting coefficients are solved based on the transient flow field data corresponding to the CFD reference point, and finally the pressure at the finite element node is obtained by weighting. There is no need for CFD and FEA mesh matching, the interpolation strictly passes through the reference point, the numerical calculation is stable, the pressure field is continuous and smooth, and it can accurately restore the spatial distribution characteristics of pressure in areas such as the volute, significantly improving the load mapping accuracy.

[0075] In some optional implementations, step S5033 includes: Step b1: Based on the spatial distance between the finite element nodes and the CFD reference points, calculate the original weights of the CFD reference points using the inverse distance weighting function.

[0076] Specifically, the spatial distance between the finite element nodes and the CFD reference points is input into the above formula (4) to obtain the original weights of all CFD reference points.

[0077] Step b2: Normalize the original weights of the CFD reference points to obtain normalized weights.

[0078] Specifically, to ensure the consistency of dimensions and numerical stability of the interpolation results, all weights involved in the interpolation are normalized. Through normalization, it can be ensured that the sum of the interpolation weights is 1, thereby avoiding deviations in the interpolation results as the number of nodes changes.

[0079] The formula for calculating the normalized weights is as follows: (6) In the above formula, Indicates the first Normalized weights of CFD reference points Indicates the number of CFD reference points. Indicates the first The original weights of the CFD reference points.

[0080] Step b3: Use normalized weights to perform weighted summation on the transient flow field data corresponding to the CFD reference point to obtain the pressure data of each finite element node.

[0081] Specifically, the physical quantities at the target finite element node (i.e., the pressure data of the target finite element node) are obtained by weighted summation of the physical quantities at the CFD reference points in the neighborhood. The calculation process is as follows: (7) In the above formula, This represents the physical quantity after interpolation at the nodes of the target finite element method. Indicates the first The original physical quantities of a CFD reference point.

[0082] In the above optional implementation, based on the spatial distance between the finite element node and the CFD reference point, the original weights are calculated and normalized using an inverse distance weighting function. The pressure of the finite element node is obtained by weighted summation, which can quickly realize the accurate mapping of the flow field pressure to the structural model, ensure smooth and continuous pressure distribution, and effectively improve the load input accuracy.

[0083] Step S5034: Based on the pressure data of each finite element node, generate the pressure distribution sequence of the finite element region step by step.

[0084] Specifically, the pressure data of each finite element node within a single time step is temporarily stored in matrix form to form a complete FEA pressure distribution matrix at that moment. Then, according to the time step sequence calculated by CFD, the above steps S5031-S5033 are repeated to form a complete pressure distribution sequence of the FEA region step by step.

[0085] For example, at each time step Interpolation is performed on the finite element nodes near the inlet of the volute. A spatial interpolation neighborhood with a radius of 1 cm is established for each finite element node in this region. Up to 50 CFD reference points are searched within the spatial interpolation neighborhood for each finite element node. The pressure value of the node is obtained by solving the weighted equation using the Gaussian radial basis function. This process is repeated on all nodes to generate a complete instantaneous pressure distribution matrix.

[0086] Step S504 involves performing consistency verification and local correction on the pressure distribution sequence of the finite element region to obtain the pressure distribution sequence of the finite element nodes. For details, please refer to [link to relevant documentation]. Figure 2Step S204 of the illustrated embodiment will not be described again here.

[0087] Step S505 involves performing transient structural dynamic response analysis based on the finite element nodal pressure distribution sequence to obtain the vibration analysis results of the target hydropower station powerhouse. For details, please refer to [link to relevant documentation]. Figure 2 Step S205 of the illustrated embodiment will not be described again here.

[0088] This embodiment provides a fluid-structure interaction method for vibration analysis of hydropower plant buildings. By constructing a spatial interpolation neighborhood and using kernel function-based interpolation, it achieves accurate spatial mapping of transient flow field data to a three-dimensional finite element model of the plant structure. It also generates a complete pressure distribution sequence step by step, fully preserving the spatial pressure distribution characteristics of flow channel regions such as the volute. This solves the problem of single-point extrapolation ignoring spatial distribution, which leads to distortion in vibration analysis.

[0089] This embodiment provides a fluid-structure interaction method for vibration analysis of hydropower plant buildings, which can be used in the aforementioned terminal equipment. Figure 6 This is a flowchart of a fluid-structure interaction method for vibration analysis of hydropower plant buildings according to an embodiment of the present invention, as shown below. Figure 6 As shown, the process includes the following steps: Step S601: Construct and solve the CFD model of the unit flow channels in the target hydropower station powerhouse to obtain transient flow field data. For details, please refer to [link to relevant documentation]. Figure 5 Step S501 of the illustrated embodiment will not be described again here.

[0090] Step S602: Construct a three-dimensional finite element model of the powerhouse structure; wherein, the three-dimensional finite element model of the powerhouse structure is consistent with the unit flow channel partitioning in the CFD model of the unit flow channel of the target hydropower station powerhouse. For details, please refer to... Figure 5 Step S502 of the illustrated embodiment will not be described again here.

[0091] Step S603 involves interpolating and mapping the transient flow field data onto the three-dimensional finite element model of the plant structure to obtain the pressure distribution sequence in the finite element region. For details, please refer to [link to relevant documentation]. Figure 5 Step S503 of the illustrated embodiment will not be described again here.

[0092] Step S604: Perform consistency verification and local correction on the pressure distribution sequence of the finite element region to obtain the pressure distribution sequence of the finite element nodes.

[0093] Specifically, step S604 includes: Step S6041: Perform a pre-check on the mapping data of the pressure distribution sequence in the finite element region.

[0094] Specifically, check whether each FEA node has found a sufficient number (≥3) of CFD source points, check whether the FEA partition and the CFD partition are completely corresponding and whether there are any omissions, and check the continuity of the boundaries of each partition region.

[0095] Furthermore, for each FEA node in the pressure distribution matrix at each time step, the spatial neighborhood search results are traced back to determine whether the number of CFD reference points participating in the interpolation in its neighborhood is greater than or equal to 3, so as to realize the validity check of each node value in the pressure distribution sequence.

[0096] Furthermore, when determining whether FEA partitions and CFD partitions completely correspond, the spatial geometric coverage relationship and partition mapping relationship (such as a predefined one-to-one correspondence between the volute, guide vane, impeller, and tailrace partitions) are used as the basis for judgment. Specifically, for a finite element node within a certain FEA partition, a neighborhood search is performed in its corresponding CFD partition node set. If all finite element nodes within the partition can find their corresponding CFD source points within a preset search radius, then the FEA partition and CFD partition are determined to be spatially completely corresponding. If there are finite element nodes that cannot match CFD source points, then the partition correspondence is determined to be incomplete. At the same time, in conjunction with the predefined mapping relationship between CFD partitions and FEA partitions, each partition is verified one by one to avoid partition omissions or duplications.

[0097] Furthermore, the boundary of a partition region refers to the set of boundary nodes where adjacent FEA partitions are spatially in contact or adjacent to each other, or the boundary region on the finite element model when multiple CFD partitions jointly cover the same FEA partition. The determination of the continuity of the partition region boundary is based on the spatial continuity of the finite element node mapping results within the boundary region. The specific steps for detecting the continuity of each partition region boundary are as follows: by identifying the finite element nodes located at the boundary of adjacent partitions, comparing the changes in the mapped physical quantities of adjacent nodes, if the difference in physical quantities between adjacent nodes is within a preset threshold range and there is no obvious abrupt change, then the partition region boundary is considered to have continuity; at the same time, the spatial distribution of CFD source points within the boundary region is checked. If the source point distribution of adjacent CFD partitions at the boundary is continuous and there are no void regions, then the boundary continuity is further confirmed to meet the requirements.

[0098] Step S6042: If the pre-check result of the mapping data meets the preset mapping conditions, then calculate the consistency judgment index of each finite element node based on the pressure distribution sequence of the finite element region; wherein, the consistency judgment index includes the spatial matching error index, the data smoothness index and the reference consistency error index.

[0099] Specifically, for each FEA node Three consistency criteria are calculated to audit the quality of the stress mapping results from CFD to FEA. For any FEA node: if any criterion exceeds the set threshold, it is marked as "needs correction"; if two or more criteria exceed the threshold at the same time, the "forced recalculation" process is initiated.

[0100] Furthermore, the spatial matching error index is calculated using the following formula: (8) in, Indicates the number of interpolation values ​​to be interpolated. Spatial coordinates of FEA nodes ( x , y , z ), This represents the spatial coordinates of the nearest CFD reference point in the neighborhood of this FEA node. This indicates spatial matching error.

[0101] Furthermore, for each FEA node Construct a local validation domain, which is defined by the nearest node to the node. It consists of 6 to 20 CFD source nodes; by selecting the nearest one for each FEA node. CFD source points (preferred) This constitutes a local validation domain. Within this domain, the mean CFD source pressure is used as a reference level. The normalized deviation of each CFD source pressure relative to the reference value is calculated, and a Local Smoothing Iteration (LSI) index is formed based on this. Local smoothness index of FEA nodes The calculation formula is: (9) in, Indicates the first Pressure at each CFD source point; This represents the average CFD pressure within the local validation domain of the FEA node; This indicates the number of CFD nodes selected within the local validation domain.

[0102] Furthermore, based on the physical foundation of the original CFD field, the mapping error is further evaluated, and the difference between the interpolated time series of a certain FEA node and the reference time series at the corresponding spatial location of the original CFD field is directly quantified; among which, for the th FEA Node RCE (Reference Consistency Error) is defined as the relative RMS (Root Mean Square) error of a time series, and its calculation formula is as follows: (10) In the above formula, Represents extremely small positive numbers (such as 1 × 10⁻⁶). -6 To prevent division by zero; This represents the total number of time steps (consistent with the time steps used in the structure solution). Indicates the first The FEA node is at the Interpolated pressure values ​​at each time step, in Pa; Indicates the first The FEA node is at the Reference pressure values ​​for each time step, in Pa; This represents the relative RMS error, also known as the reference consistency error, and is a dimensionless number.

[0103] The original CFD field is usually not taken at the FEA node and needs to be obtained by high-precision reconstruction of CFD data or local reference interpolation. The selection of sampling points and the construction of the reference field directly determine the reliability of the index. Therefore, the local high-density neighborhood method or the regional representative point method is used for sampling. For sampling points near the boundary and in high-gradient regions, the local high-density neighborhood method can be given priority; for regions with small gradient changes and uniform grid density within the boundary, the regional representative point method can be given priority. The two sampling strategies are as follows: Local high-density neighborhood method: for the first FEA Node First, search within the CFD source set. nearest neighbor CFD points (by distance). The value can be 50~200, and the initial value can be 100; or the coverage radius can be taken at the CFD source point. (The local cell size can be 1 to 3 times the CFD size), and all CFD points are taken within this radius (random / uniform sampling can be used if the number of points is greater than 200); then, a higher-order / more stable reconstruction method is used to generate... For example: local RBF (Gaussian kernel) or local polynomial fitting with Tikhonov regularization (a method for solving ill-conditioned systems or minimizing generalization error); local fitting based on weighted least squares; weights corrected by negative powers of distance, grid area or grid quality; finally, reconstruction at each time step independently or using time-domain shared coefficients.

[0104] Regional representative point method: Several representative points are pre-selected in each CFD region (based on gradient distribution, curvature and geometric features). If the FEA node is very close to a representative point (less than the preset distance), the CFD time history of that representative point is directly used as a reference (for acceleration).

[0105] Step S6043: Compare the consistency judgment index with the preset threshold, and make local corrections to the pressure distribution sequence of the finite element region based on the comparison results to obtain the pressure distribution sequence of the finite element nodes.

[0106] Specifically, the spatial matching error index is used to measure whether the geometric correspondence between the nearest CFD source point and the FEA node is reasonable. When the threshold is exceeded, it indicates that the geometric fit between the FEA node and its corresponding CFD data point is insufficient. The reasons may include that the CFD mesh is too coarse, the FEA mesh is too coarse, or the mesh scales of the two are mismatched in a local area; it may also be due to inconsistent CFD region filtering logic, which causes the FEA node to fail to match the correct CFD sub-region. Such FEA nodes should be marked as "geometric high-risk points" and the following correction methods can be adopted: appropriately increase the neighborhood search radius or the number of reference points, adjust the interpolation function and its parameters, modify the mesh model, etc.

[0107] in, The values ​​should be adjusted appropriately based on the actual project. For typical projects, the initial values ​​can be referenced. ,like If so, it is marked as a "geometric high-risk point"; among them, This refers to the characteristic dimensions of the volute or flow channel (e.g., the diameter of the volute throat). If the hydraulic diameter of the volute throat... The qualified threshold If the distance between a certain FEA node and the nearest CFD reference point is 0.10 m, it is considered a risk point and the corresponding CFD region filtering logic needs to be checked.

[0108] Furthermore, if the LSI exceeds a preset threshold (e.g., 5%), it indicates that there is a sudden change or noise in the pulsating pressure field near the FEA node, which may be caused by interpolation error at the dynamic-static interface, local mesh distortion, or CFD partitioning error. The node will be locally corrected: spatial smoothing (distance-weighted averaging) of the local area to suppress isolated points; appropriate adjustment of the interpolation weight attenuation coefficient (to make the weights more uniform) to reduce the dominance of discrete points on the results; and for nodes that cross the CFD region boundary, introducing cross-region fusion weights (i.e., different CFD partitions are given different weights according to area or distance), etc.

[0109] in, The following values ​​can be used as a reference for the judgment criteria: The interpolation is good and requires no further processing. It is important to note that there may be CFD mesh inhomogeneity, noise at the dynamic-static interface, and fluctuations near the boundary. This is unreliable and may contain local pressure anomalies, CFD partitioning errors, mesh distortion, and sampling errors.

[0110] Furthermore, for regions where the interpolation reconstruction consistency error (i.e., reference consistency error) exceeds the threshold, the following three types of local correction strategies can be adopted: interpolation mapping function optimization, neighborhood data reconstruction, and grid scale correction. By locally replacing the kernel function, expanding the neighborhood, cross-regional fusion interpolation, and modifying the grid model, the interpolation results can be made to conform to the trend characteristics of the original CFD pressure field again.

[0111] in, The following values ​​can be used as a reference for the judgment criteria: The fit is good; The deviation is small and acceptable; If a significant deviation is found, it will be corrected.

[0112] Step S605 involves performing transient structural dynamic response analysis based on the finite element nodal pressure distribution sequence to obtain the vibration analysis results of the target hydropower station powerhouse. For details, please refer to [link to relevant documentation]. Figure 5 Step S505 of the illustrated embodiment will not be described again here.

[0113] This embodiment provides a fluid-structure interaction method for vibration analysis of hydropower plant buildings. It pre-checks the mapping data of the pressure distribution sequence in the finite element region, filtering out invalid mapping data in advance to avoid interference from invalid data in subsequent analysis, reducing the workload of local corrections, and improving overall process efficiency. Then, based on the pressure distribution sequence of the finite element region, it calculates the consistency judgment index for each finite element node, quantitatively verifying the quality of the pressure distribution sequence from multiple dimensions. Based on the comparison results of the consistency judgment index and preset thresholds, it performs local corrections on the pressure distribution sequence of the finite element region, avoiding full-domain recalculation, specifically addressing abnormal area problems, ensuring the reliability and rationality of the pressure distribution sequence of the finite element nodes, and providing high-quality load input for subsequent structural vibration analysis.

[0114] This embodiment provides a fluid-structure interaction method for vibration analysis of hydropower plant buildings, which can be used in the aforementioned terminal equipment. Figure 7 This is a flowchart of a fluid-structure interaction method for vibration analysis of hydropower plant buildings according to an embodiment of the present invention, as shown below. Figure 7 As shown, the process includes the following steps: Step S701: Construct and solve the CFD model of the unit flow channels in the target hydropower station powerhouse to obtain transient flow field data. For details, please refer to [link to relevant documentation]. Figure 6 Step S601 of the illustrated embodiment will not be described again here.

[0115] Step S702: Construct a three-dimensional finite element model of the powerhouse structure; wherein, the three-dimensional finite element model of the powerhouse structure is consistent with the unit flow channel partitioning in the CFD model of the unit flow channel of the target hydropower station powerhouse. For details, please refer to... Figure 6 Step S602 of the illustrated embodiment will not be described again here.

[0116] Step S703 involves interpolating and mapping the transient flow field data onto the three-dimensional finite element model of the plant structure to obtain the pressure distribution sequence in the finite element region. For details, please refer to [link to relevant documentation]. Figure 6 Step S603 of the illustrated embodiment will not be described again here.

[0117] Step S704 involves performing consistency verification and local correction on the pressure distribution sequence of the finite element region to obtain the pressure distribution sequence of the finite element nodes. For details, please refer to [link to relevant documentation]. Figure 6 Step S604 of the illustrated embodiment will not be described again here.

[0118] Step S705: Perform transient structural dynamic response analysis based on the finite element nodal pressure distribution sequence to obtain the vibration analysis results of the target hydropower station powerhouse.

[0119] Specifically, step S705 includes: Step S7051: Based on the time step matching relationship between finite element nodes and CFD flow field nodes, the pressure distribution sequence of finite element nodes is synchronously extracted to obtain the node pressure data corresponding to the finite element time step.

[0120] Specifically, because CFD solvers must use extremely small time steps to capture high-frequency pressure fluctuations (such as blade frequency and vortex belt fluctuations) in the volute and impeller regions, while FEA structural analysis does not require high time resolution, a larger time step can significantly improve computational efficiency. Therefore, in order to accurately match the high-density temporal pressure data of CFD to the low-density time step of FEA without losing the transient characteristics of the flow field, and to achieve complete consistency of fluid-structure interaction in the time domain, thus avoiding structural response distortion caused by time misalignment, time domain synchronization is required.

[0121] Furthermore, in typical scenarios such as pumped storage power stations, the time steps of the CFD solver and the FEA solver typically satisfy the following: (11) In the above formula, This refers to the computation time step of the FEA solver. This refers to the computation time step of the CFD solver. express m It is a positive integer, meaning that the time step of FEA is usually an integer multiple of CFD.

[0122] Furthermore, based on the time step matching relationship between the finite element nodes and the CFD flow field nodes as expressed in formula (11), the time series data from the CFD can be directly extracted at a fixed step size: (12) In the above formula, Indicates CFD in the 1st The nodal pressure values ​​at each time step are determined based on the finite element nodal pressure distribution sequence. This indicates that after synchronous extraction, it is used for the FEA (Feature A) stage. The node pressure values ​​at each time step; where the formula for calculating the step size multiple is: (13) Step S7052: The nodal pressure data corresponding to the finite element time step is used as the surface pressure load and applied to the unit flow channel region in the three-dimensional finite element model of the powerhouse structure. Transient structural dynamic response analysis is then performed to obtain the vibration analysis results of the target hydropower station powerhouse.

[0123] Specifically, after time-domain synchronization is completed, the nodal pressure data corresponding to each FEA time step is applied as surface pressure load to the nodes or surfaces corresponding to the FEA flow channel regions (SP, SV, GV, DT, etc.), and structural transient dynamic analysis is performed using finite element software (such as ANSYS, Abaqus, etc.).

[0124] When using the implicit time integration method, the steps of the transient dynamic analysis of the structure are as follows: First, the analysis time domain is discretized into several time steps and synchronized with the time domain of the CFD pressure data; based on the known structural response of the previous time step, the equivalent equation of the current time step is constructed, the nodal displacement is obtained by solving the equation set, and the nodal velocity and acceleration are further updated, thereby obtaining the time history response of nodal displacement, velocity and acceleration.

[0125] When using the explicit time integration method, the steps of the transient dynamic analysis of the structure are as follows: calculate the nodal acceleration directly based on the external load of the current time step, and update the nodal velocity and displacement sequentially through time integration. There is no need to solve the global equation system within the current time step, and the transient response time history of each node of the structure is gradually obtained.

[0126] Furthermore, after completing the time step progression, the vibration analysis results of the target hydropower plant are output, namely, the nodal displacement, velocity, acceleration, and stress and acceleration response results at key locations, which are used for vibration analysis and evaluation of the plant structure.

[0127] Furthermore, it provides a unified output format for post-processing and vibration evaluation: output displacement / stress / acceleration time histories by time step; generate structural vibration amplitude spectra by region; generate spectrum diagrams based on energy distribution in specified frequency bands, etc.

[0128] This embodiment provides a fluid-structure interaction (FSI) method for vibration analysis of hydropower plant buildings. By synchronously extracting the pressure distribution sequence of finite element nodes according to the time step matching relationship between finite element nodes and CFD flow field nodes, it ensures complete alignment between the CFD transient pressure and the FEA dynamic analysis time domain. This achieves precise synchronization of the FSI time domain, avoiding excitation distortion caused by timing misalignment, and accurately reflecting the characteristics of hydraulic pulsations over time. It preserves the amplitude and frequency characteristics of the original flow field pressure pulsations to the maximum extent. Furthermore, the node pressure data corresponding to the finite element time step is used as a surface pressure load and applied to the unit flow channel region in the three-dimensional finite element model of the power plant structure. Transient structural dynamic response analysis is then performed, accurately reflecting the dynamic characteristics of the hydropower plant under complex hydraulic pulsations, significantly improving the accuracy and engineering applicability of the vibration analysis results.

[0129] This embodiment also provides a fluid-structure interaction device for vibration analysis of hydropower plant buildings. This device is used to implement the above embodiments and preferred embodiments, and details already described will not be repeated. As used below, the term "module" can refer to a combination of software and / or hardware that performs a predetermined function. Although the device described in the following embodiments is preferably implemented in software, hardware implementation, or a combination of software and hardware, is also possible and contemplated.

[0130] This embodiment provides a fluid-structure interaction device for vibration analysis of hydropower plant buildings, such as... Figure 8 As shown, it includes: The solver module 801 is used to construct and solve the CFD model of the unit flow channel of the target hydropower station powerhouse to obtain transient flow field data; Module 802 is used to construct a three-dimensional finite element model of the powerhouse structure; wherein, the three-dimensional finite element model of the powerhouse structure is consistent with the unit flow channel partition in the CFD model of the unit flow channel of the target hydropower station powerhouse. The mapping module 803 is used to interpolate and map transient flow field data to a three-dimensional finite element model of the plant structure to obtain the pressure distribution sequence of the finite element region. The correction module 804 is used to perform consistency verification and local correction processing on the pressure distribution sequence of the finite element region to obtain the pressure distribution sequence of the finite element nodes. Analysis module 805 is used to perform transient structural dynamic response analysis based on the finite element nodal pressure distribution sequence, and obtain the vibration analysis results of the target hydropower plant.

[0131] In some alternative implementations, the mapping module 803 includes: The search unit is used to construct a spatial interpolation neighborhood for each finite element node in the three-dimensional finite element model of the plant structure, and to search for multiple CFD flow field nodes as CFD reference points within the spatial interpolation neighborhood based on transient flow field data. Building units are used to construct kernel functions; The solver unit is used to perform interpolation based on CFD reference points and kernel functions for each finite element node to obtain the pressure data of each finite element node. The generation unit is used to generate a pressure distribution sequence of the finite element region step by step based on the pressure data of each finite element node.

[0132] In some alternative implementations, the solving unit includes: Sub-elements are constructed to build a radial basis function matrix based on the spatial distance between finite element nodes and CFD reference points using radial basis functions. Establish sub-units for building linear equation systems based on radial basis function matrices; The solution sub-element is used to solve the linear equations based on the transient flow field data corresponding to the CFD reference point, and to obtain the interpolation weighting coefficients. The first computational sub-unit is used to calculate the pressure data of each finite element node based on the interpolation weighting coefficients and the radial basis function matrix.

[0133] In some alternative implementations, the solving unit includes: The second calculation sub-unit is used to calculate the original weight of the CFD reference point based on the spatial distance between the finite element node and the CFD reference point using the inverse distance weighting function. The normalization processing sub-unit is used to normalize the original weights of the CFD reference points to obtain normalized weights. The weighted summation sub-element is used to perform weighted summation on the transient flow field data corresponding to the CFD reference point using normalized weights to obtain the pressure data of each finite element node.

[0134] In some alternative implementations, the correction module 804 includes: The pre-check unit is used to perform pre-checks on the mapping data of the pressure distribution sequence in the finite element region. The calculation unit is used to calculate the consistency judgment index of each finite element node based on the pressure distribution sequence of the finite element region if the pre-check result of the mapping data meets the preset mapping conditions; wherein, the consistency judgment index includes the spatial matching error index, the data smoothness index and the reference consistency error index. The local correction unit is used to compare the consistency judgment index with the preset threshold, and to locally correct the pressure distribution sequence of the finite element region based on the comparison result, so as to obtain the pressure distribution sequence of the finite element nodes.

[0135] In some alternative implementations, the analysis module 805 includes: The extraction unit is used to synchronously extract the pressure distribution sequence of the finite element nodes according to the time step matching relationship between the finite element nodes and the CFD flow field nodes, so as to obtain the node pressure data corresponding to the finite element time step. The analysis unit is used to apply the nodal pressure data corresponding to the finite element time step as a surface pressure load to the unit flow channel region in the three-dimensional finite element model of the powerhouse structure, and to perform transient structural dynamic response analysis to obtain the vibration analysis results of the target hydropower station powerhouse.

[0136] The fluid-structure interaction device for vibration analysis of hydropower plant provided in this embodiment of the invention can execute the fluid-structure interaction method for vibration analysis of hydropower plant provided in any embodiment of the invention, and has the corresponding functional modules and beneficial effects of the method. Further functional descriptions of the above modules and units are the same as in the corresponding embodiments described above, and will not be repeated here.

[0137] Figure 9 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present invention.

[0138] The following is a detailed reference. Figure 9 This diagram illustrates a structural schematic suitable for implementing an electronic device according to embodiments of the present invention. The electronic device may include a processor (e.g., a central processing unit, graphics processor, etc.) 901, which can perform various appropriate actions and processes according to a program stored in read-only memory (ROM) 902 or a program loaded from memory 908 into random access memory (RAM) 903. The RAM 903 also stores various programs and data required for the operation of the electronic device. The processor 901, ROM 902, and RAM 903 are interconnected via a bus 904. An input / output (I / O) interface 905 is also connected to the bus 904.

[0139] Typically, the following devices can be connected to I / O interface 905: input devices 906 including, for example, touchscreens, touchpads, keyboards, mice, cameras, microphones, accelerometers, gyroscopes, etc.; output devices 907 including, for example, liquid crystal displays (LCDs), speakers, vibrators, etc.; memory devices 908 including, for example, magnetic tapes, hard disks, etc.; and communication devices 909. Communication device 909 allows electronic devices to exchange data via wireless or wired communication with other devices. Although Figure 9 Electronic devices with various devices are shown, but it should be understood that it is not required to implement or have all of the devices shown, and more or fewer devices may be implemented or have instead.

[0140] In particular, according to embodiments of the present invention, the processes described above with reference to the flowcharts can be implemented as computer software programs. For example, embodiments of the present invention include a computer program product comprising a computer program carried on a non-transitory computer-readable medium, the computer program containing program code for performing the methods shown in the flowcharts. In such embodiments, the computer program can be downloaded and installed from a network via a communication device 909, or installed from a memory 908, or installed from a ROM 902. When the computer program is executed by a processor 901, it performs the functions defined in the fluid-structure interaction method for vibration analysis of a hydropower plant according to embodiments of the present invention.

[0141] Figure 9 The electronic device shown is merely an example and should not be construed as limiting the functionality and scope of the embodiments of the present invention.

[0142] This invention also provides a computer-readable storage medium. The methods described above according to embodiments of the invention can be implemented in hardware or firmware, or implemented as computer code that can be recorded on a storage medium, or implemented as computer code downloaded via a network and originally stored on a remote storage medium or a non-transitory machine-readable storage medium and then stored on a local storage medium. Thus, the methods described herein can be processed by software stored on a storage medium using a general-purpose computer, a dedicated processor, or programmable or dedicated hardware. The storage medium can be a magnetic disk, optical disk, read-only memory, random access memory, flash memory, hard disk, or solid-state drive, etc.; further, the storage medium can also include combinations of the above types of memory. It is understood that computers, processors, microprocessor controllers, or programmable hardware include storage components capable of storing or receiving software or computer code. When the software or computer code is accessed and executed by the computer, processor, or hardware, it implements the fluid-structure interaction method for vibration analysis of hydropower plant buildings shown in the above embodiments.

[0143] A portion of this invention can be applied as a computer program product, such as computer program instructions, which, when executed by a computer, can invoke or provide the methods and / or technical solutions according to the invention through the operation of the computer. Those skilled in the art will understand that the forms in which computer program instructions exist in a computer-readable medium include, but are not limited to, source files, executable files, installation package files, etc. Correspondingly, the ways in which computer program instructions are executed by a computer include, but are not limited to: the computer directly executing the instructions, or the computer compiling the instructions and then executing the corresponding compiled program, or the computer reading and executing the instructions, or the computer reading and installing the instructions and then executing the corresponding installed program. Here, the computer-readable medium can be any available computer-readable storage medium or communication medium accessible to a computer.

[0144] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A fluid-structure interaction method for vibration analysis of hydropower plant buildings, characterized in that, The method includes: Construct and solve the CFD model of the unit flow channel of the target hydropower station powerhouse to obtain transient flow field data; A three-dimensional finite element model of the powerhouse structure is constructed; wherein, the three-dimensional finite element model of the powerhouse structure is consistent with the unit flow channel partition in the CFD model of the unit flow channel of the target hydropower station powerhouse; The transient flow field data is interpolated and mapped onto the three-dimensional finite element model of the plant structure to obtain the pressure distribution sequence in the finite element region. The pressure distribution sequence of the finite element region is subjected to consistency verification and local correction processing to obtain the pressure distribution sequence of the finite element nodes. Based on the finite element nodal pressure distribution sequence, transient structural dynamic response analysis was performed to obtain the vibration analysis results of the target hydropower station powerhouse.

2. The method according to claim 1, characterized in that, The step of interpolating and mapping the transient flow field data to the three-dimensional finite element model of the plant structure to obtain the pressure distribution sequence in the finite element region includes: For each finite element node in the three-dimensional finite element model of the factory structure, a spatial interpolation neighborhood is constructed, and based on the transient flow field data, multiple CFD flow field nodes are searched within the spatial interpolation neighborhood as CFD reference points. Construct the kernel function; For each finite element node, based on the CFD reference point, the kernel function is used to perform interpolation to obtain the pressure data of each finite element node; Based on the pressure data of each finite element node, a pressure distribution sequence of the finite element region is generated step by step over time.

3. The method according to claim 2, characterized in that, For each finite element node, based on the CFD reference point, interpolation is performed using the kernel function to obtain the pressure data for each finite element node. This includes the kernel function being a radial basis function. Based on the spatial distance between the finite element nodes and the CFD reference points, a radial basis function matrix is ​​constructed using the radial basis functions. A system of linear equations is established based on the radial basis function matrix; Based on the transient flow field data corresponding to the CFD reference point, the linear equation system is solved to obtain the interpolation weighting coefficients; The pressure data of each finite element node is calculated based on the interpolation weight coefficients and the radial basis function matrix.

4. The method according to claim 2, characterized in that, For each finite element node, based on the CFD reference point, interpolation is performed using the kernel function to obtain the pressure data for each finite element node. This includes the kernel function being an inverse distance weighted function. Based on the spatial distance between the finite element node and the CFD reference point, the original weight of the CFD reference point is calculated using the inverse distance weighting function. The original weights of the CFD reference points are normalized to obtain normalized weights. The pressure data of each finite element node is obtained by weighting and summing the transient flow field data corresponding to the CFD reference point using the normalized weights.

5. The method according to claim 1, characterized in that, The process of performing consistency verification and local correction on the pressure distribution sequence of the finite element region to obtain the pressure distribution sequence of the finite element nodes includes: Pre-check the mapping data of the pressure distribution sequence in the finite element region; If the pre-check result of the mapping data meets the preset mapping conditions, then based on the pressure distribution sequence of the finite element region, the consistency judgment index of each finite element node is calculated; wherein, the consistency judgment index includes the spatial matching error index, the data smoothness index and the reference consistency error index. The consistency judgment index is compared with a preset threshold, and the pressure distribution sequence of the finite element region is locally corrected based on the comparison result to obtain the pressure distribution sequence of the finite element nodes.

6. The method according to claim 1, characterized in that, The transient structural dynamic response analysis based on the finite element nodal pressure distribution sequence yields the vibration analysis results of the target hydropower station powerhouse, including: Based on the time step matching relationship between finite element nodes and CFD flow field nodes, the pressure distribution sequence of the finite element nodes is synchronously extracted to obtain the node pressure data corresponding to the finite element time step. The nodal pressure data corresponding to the finite element time step are used as surface pressure loads and applied to the unit flow channel region in the three-dimensional finite element model of the powerhouse structure. Transient structural dynamic response analysis is then performed to obtain the vibration analysis results of the target hydropower station powerhouse.

7. A fluid-structure interaction device for vibration analysis of hydropower plant buildings, characterized in that, The device includes: The solver module is used to construct and solve the CFD model of the unit flow channel of the target hydropower station powerhouse to obtain transient flow field data; A construction module is used to construct a three-dimensional finite element model of the powerhouse structure; wherein, the three-dimensional finite element model of the powerhouse structure is consistent with the unit flow channel partition in the CFD model of the unit flow channel of the target hydropower station powerhouse; The mapping module is used to interpolate and map the transient flow field data to the three-dimensional finite element model of the plant structure to obtain the pressure distribution sequence of the finite element region; The correction module is used to perform consistency verification and local correction processing on the pressure distribution sequence of the finite element region to obtain the pressure distribution sequence of the finite element nodes. The analysis module is used to perform transient structural dynamic response analysis based on the finite element node pressure distribution sequence, and obtain the vibration analysis results of the target hydropower plant.

8. An electronic device, characterized in that, include: The system includes a memory and a processor, which are interconnected. The memory stores computer instructions, and the processor executes the computer instructions to perform the fluid-structure interaction method for vibration analysis of hydropower plant buildings as described in any one of claims 1 to 6.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer instructions for causing the computer to execute the fluid-structure interaction method for vibration analysis of hydropower plant buildings as described in any one of claims 1 to 6.

10. A computer program product, characterized in that, Includes computer instructions for causing a computer to execute the fluid-structure interaction method for vibration analysis of hydropower plant buildings as described in any one of claims 1 to 6.

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