Method and system for simulating pulsating wind field of cable-stayed pipe bridge

Abstract

The invention relates to the technical field of cable-stayed pipe bridge wind field simulation, and discloses a cable-stayed pipe bridge fluctuating wind field simulation method and system, and the method comprises the steps: building a parameter system, dynamically adjusting the number of sample points, synthesizing a fluctuating wind field, and carrying out the automatic feedback verification. According to the method, a simulation system containing in-pipe oil-gas medium parameters is constructed, and the number of sample points of wind field space discrete points is dynamically adjusted based on the Reynolds number, so that the in-pipe and out-pipe flow-solid coupling effect is accurately represented. According to the method, redundant calculation can be reduced in a laminar flow state, and the capability of capturing high-frequency turbulent flow details is enhanced in a turbulent flow state, so that the calculation efficiency is remarkably improved while the simulation precision is ensured, and the contradiction between the precision and the efficiency of a traditional fixed sample point method is solved; according to the system, simulation, verification and interaction functions are integrated, the operation threshold is greatly reduced, the convenience and reliability of engineering design are improved, and an efficient and reliable special tool is provided for wind resistance design and safety evaluation of the cable-stayed pipe bridge.

Description

Technical Field

[0001] This invention belongs to the field of wind field simulation technology for cable-stayed pipe bridges, specifically relating to a method and system for simulating pulsating wind fields in cable-stayed pipe bridges, and more particularly to a method and interactive simulation system for simulating pulsating wind fields in cable-stayed pipe bridges that considers the characteristics of oil and gas inside the pipe and pipeline parameters. Background Technology

[0002] As the core structure of long-distance oil and gas pipelines crossing complex terrain (such as valleys and rivers), the wind-induced vibration safety of cable-stayed bridges directly determines the stability of oil and gas transportation. In the wind-resistant design of cable-stayed bridges, accurate simulation of pulsating wind fields is a prerequisite for analyzing wind-induced vibration response and formulating vibration reduction strategies.

[0003] In existing technologies, bridge wind field simulations mostly refer to the research methods of ordinary cable-stayed bridges, which mainly have the following problems: Ignoring the coupling characteristics of pipe-bridge systems: Traditional wind field simulations only consider the geometric and mechanical parameters of the bridge structure (main beam, cables, main tower), neglecting the oil and gas medium inside the pipe (density, dynamic viscosity, flow velocity) and the pipe's own parameters (diameter, wall thickness, length). This fails to reflect the fluid-structure interaction effect between the oil and gas flow inside the pipe and the wind field outside, leading to significant deviations between simulation results and actual engineering scenarios. For example, when the oil and gas inside the pipe are in a turbulent state, they will transmit vibrations to the wind field outside the pipe through the pipe wall, changing the local wind velocity and flow pattern. Existing simulation methods do not consider this effect and tend to underestimate the risk of wind-induced vibration.

[0004] The lack of dynamism in sample point adjustment: In existing wind field simulations, the number of sample points for spatially discrete points is mostly a fixed value, and is not dynamically adjusted according to the oil and gas flow state (laminar, transitional, turbulent) inside the pipe. When the oil and gas flow state changes from laminar to turbulent, the turbulent characteristics of the wind field outside the pipe change significantly. A fixed number of sample points is insufficient to capture high-frequency turbulent details, resulting in insufficient simulation accuracy; while a fixed number of sample points under laminar flow conditions will increase unnecessary computation and reduce simulation efficiency.

[0005] Poor simulation result verification and interactivity: Existing simulation tools are mostly single calculation programs that lack a visual interactive interface, making it difficult for users to quickly adjust key parameters (such as land surface type, design wind speed, and observation height) and view results in real time; at the same time, the error judgment between the simulated power spectrum and the standard power spectrum mostly relies on manual post-processing, and no automatic feedback adjustment mechanism has been established. When the error exceeds the tolerance, the program needs to be run manually again, which is cumbersome and inefficient. Summary of the Invention

[0006] The purpose of this invention is to provide a method and system for simulating pulsating wind fields of cable-stayed bridges, which solves the problems of cable-stayed bridge coupling characteristics, lack of dynamic adjustment of sample points, and poor verification and interactivity of simulation results. It achieves accurate characterization of the pipe-wind coupling effect, real-time adjustment of simulation parameters, automatic error correction, and visualization of results, thereby improving the convenience and reliability of simulation operation.

[0007] Based on the above concept, the technical solution adopted by this invention is as follows: According to a first aspect of the present invention, a method for simulating pulsating wind fields in a cable-stayed bridge is provided, comprising the following steps: S1. Constructing the parameter system Acquire and input wind field parameters, structural parameters of the cable-stayed bridge, and medium parameters of the oil and gas medium inside the pipe; S2, Dynamically adjust the number of sample points Based on the medium parameters and pipe diameter, calculate the Reynolds number Re of the oil and gas inside the pipe; Based on the flow regime range where the Reynolds number Re is located, the number of sample points for spatial discrete points used in pulsating wind field simulation is dynamically adjusted. S3, Synthetic Pulsating Wind Field Based on the adjusted number of sample points, the harmonic synthesis method is used to generate the time history of fluctuating wind speed at each spatial discrete point; S4, Automatic Feedback Verification Calculate the simulated power spectrum corresponding to the synthesized time history of fluctuating wind speed in step S3; The simulated power spectrum is compared with the preset standard power spectrum. If the error exceeds the tolerance range, step S3 is repeated until the error meets the tolerance requirements, and then the final pulsating wind speed time history is output.

[0008] In some embodiments, step S2, dynamically adjusting the number of sample points according to the Reynolds number Re, specifically includes: When the Reynolds number Re < 2300, it is determined to be laminar flow, and the number of sample points is multiplied by a first adjustment factor less than 1; When the Reynolds number is 2300≤Re≤4000, it is determined to be a transient flow, and the number of sample points is multiplied by a second adjustment factor greater than 1; When the Reynolds number Re > 4000, it is determined to be turbulent, and the number of sample points is multiplied by a third adjustment factor that is greater than the second adjustment factor.

[0009] In some embodiments, the first adjustment factor is 0.7 to 0.9, the second adjustment factor is 1.1 to 1.3, and the third adjustment factor is 1.4 to 1.6.

[0010] Furthermore, the first adjustment factor is 0.8, the second adjustment factor is 1.2, and the third adjustment factor is 1.5.

[0011] In some embodiments, in step S4, the random phase in the harmonic synthesis method is corrected by iterative correction in order to achieve error convergence between the simulated power spectrum and the standard power spectrum.

[0012] In some embodiments, the system further includes receiving user-input parameters in real time via a graphical user interface and visually displaying the time history of the fluctuating wind speed, the comparison results of the simulated power spectrum, and the correlation coefficient.

[0013] In some embodiments, the graphical user interface also supports the correction of the height of the wind speed point of the main beam, the correction being based on a quadratic function fitting of the influence of gravity and deflection on the height.

[0014] According to a second aspect of the present invention, a system for simulating fluctuating wind fields in a cable-stayed bridge is provided, the system comprising: The parameter input module is used to receive wind field parameters, structural parameters, and medium parameters input by the user. The dynamic adjustment module is used to calculate the Reynolds number of oil and gas in the pipe and dynamically determine the number of sample points for spatial discrete points based on the Reynolds number. The wind field synthesis module is used to synthesize the time history of pulsating wind speed based on the harmonic synthesis method and the number of sample points determined by the dynamic adjustment module. An automatic feedback verification module is used to compare the simulated power spectrum of the synthesized wind field with the standard power spectrum, and control the wind field synthesis module to resynthesize when the error exceeds the tolerance until the error meets the requirements. The results display module is used to output and visualize the final pulsed wind speed time history and related comparison charts.

[0015] According to a third aspect of the present invention, a computer-readable storage medium is provided having a computer program stored thereon, which, when executed by a processor, implements the above-described method for simulating pulsating wind fields in cable-stayed bridges.

[0016] The beneficial effects of this invention are as follows: 1. This invention achieves accurate characterization of the fluid-structure interaction effect inside and outside the pipe by constructing a simulation system that includes parameters of the oil and gas medium inside the pipe and dynamically adjusting the number of sample points for the discrete points of the wind field based on the Reynolds number. This method reduces redundant calculations under laminar flow conditions and enhances the ability to capture high-frequency turbulent details under turbulent flow conditions, thus significantly improving computational efficiency while ensuring simulation accuracy.

[0017] 2. This invention integrates an automatic feedback verification mechanism with a graphical user interface, enabling real-time adjustment of simulation parameters, automatic correction of power spectrum errors, and visualization of results. The system integrates simulation, verification, and interactive functions, significantly reducing the operational threshold and improving the convenience and reliability of engineering design. It provides an efficient and reliable dedicated tool for the wind-resistant design and safety assessment of cable-stayed bridges. Attached Figure Description

[0018] Figure 1 This is a spatial discrete wind speed point distribution diagram along the main beam direction of the cable-stayed bridge of the present invention; Figure 2 This is the overall flowchart of the simulation of the pulsating wind field of the cable-stayed bridge of the present invention; Figure 3 This is a diagram of the interactive pulsating wind field simulation GUI interface of the present invention; Figure 4 This is the logic diagram for adjusting the number of sample points under different flow states in this invention. Detailed Implementation

[0019] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numerals in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Rather, they are merely examples of apparatuses and methods consistent with some aspects of the invention as detailed in the appended claims.

[0020] The terminology used in this application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. Unless otherwise defined, the technical or scientific terms used in this application should be understood in their ordinary sense by one of ordinary skill in the art to which this invention pertains. The words “a” or “one” and similar terms used in this application specification and claims do not indicate a limitation of quantity, but rather indicate the presence of at least one. “A plurality” means two or more. The words “comprising” or “including” and similar terms mean that the element or object preceding “comprising” or “including” covers the element or object listed following “comprising” or “including” and its equivalents, and does not exclude other elements or objects. The words “connected” or “linked” and similar terms are not limited to physical or mechanical connections and can include electrical connections, whether direct or indirect. The words “above” and / or “below” and similar terms are for ease of description only and are not limited to a location or spatial orientation. The singular forms “a,” “the,” and “the” used in this application specification and appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any or all possible combinations of one or more associated listed items.

[0021] This application provides a method and system for simulating pulsating wind fields in cable-stayed bridges, including the following steps: S1. Constructing the parameter system Acquire and input wind field parameters, structural parameters of the cable-stayed bridge, and medium parameters of the oil and gas medium inside the pipe; S2, Dynamically adjust the number of sample points Based on the parameters of the oil and gas medium inside the pipe and the pipe diameter, calculate the Reynolds number Re of the oil and gas inside the pipe; Based on the flow regime range where the Reynolds number Re is located, the number of sample points for spatial discrete points used in pulsating wind field simulation is dynamically adjusted. S3, Synthetic Pulsating Wind Field Based on the adjusted number of sample points, the harmonic synthesis method is used to generate the time history of fluctuating wind speed at each spatial discrete point; S4, Automatic Feedback Verification Calculate the simulated power spectrum corresponding to the synthesized time history of fluctuating wind speed in step S3; The simulated power spectrum is compared with the preset standard power spectrum. If the error exceeds the tolerance range, step S3 is repeated until the error meets the tolerance requirements, and then the final pulsating wind speed time history is output.

[0022] This invention achieves accurate characterization of the fluid-structure interaction effect inside and outside the pipe by constructing a simulation system that includes parameters of the oil and gas medium inside the pipe and dynamically adjusting the number of sample points for discrete points in the wind field based on the Reynolds number. This method reduces redundant calculations under laminar flow conditions and enhances the ability to capture high-frequency turbulent details under turbulent flow conditions, thus significantly improving computational efficiency while ensuring simulation accuracy and resolving the contradiction between accuracy and efficiency inherent in traditional fixed-sample-point methods. The system integrates simulation, verification, and interactive functions, greatly reducing the operational threshold and improving the convenience and reliability of engineering design, providing an efficient and reliable dedicated tool for the wind-resistant design and safety assessment of cable-stayed pipe bridges.

[0023] S1. Constructing an integrated parameter system First, a complete system integrating three types of parameters—wind field, structure, and medium—is constructed as the input basis for the simulation. Specific parameters are input through a graphical user interface, such as... Figure 3 As shown: Wind field parameters: Selected based on site conditions. In this embodiment, the surface type is selected as Class B, corresponding to a surface roughness coefficient α=0.16, a roughness height z0=0.05m, a design wind speed of 30m / s, and a base wind speed of 28.5m / s.

[0024] The number of spatial discrete points is set to 29 points based on the main beam length and cable spacing. A schematic diagram showing their distribution along the main beam is provided below. Figure 1 .

[0025] Furthermore, in this embodiment, the main beam length is 284m and the cable spacing is 10m.

[0026] Structural parameters: These mainly refer to the parameters of the conveying pipeline. In this embodiment, the pipeline has an outer diameter of 0.72m, a wall thickness of 0.014m, a length of 284m, and is made of X60 grade pipeline steel with an elastic modulus of 2.06 × 10⁻⁶. 11 Pa.

[0027] Medium parameters: These describe the characteristics of the oil and gas flowing inside the pipe. In this embodiment, the density is 889 kg / m³. 3 The dynamic viscosity is 0.1 Pa·s, and the flow rate is 2 m / s.

[0028] S2. Dynamic adjustment of sample points based on Reynolds number This step is crucial for achieving a balance between accuracy and efficiency; its logical flow can be found in [link to relevant documentation]. Figure 4 The system automatically reads the medium parameters and pipe diameter input in step S1 and calculates the Reynolds number Re of the oil and gas inside the pipe. The calculation formula is:

[0029] in, For oil and gas density, For oil and gas flow rate, For pipe diameter, This refers to the dynamic viscosity of oil and gas.

[0030] Based on the calculated Reynolds number, the system automatically determines the flow regime and dynamically adjusts the number of spatial discrete point samples used for wind field simulation: If Re < 2300 (laminar flow state), then multiply the initial number of sample points by the first adjustment factor of 0.8. In this state, the fluid inside the pipe is stable, and the disturbance to the wind field outside the pipe is small. Reducing the number of sample points can effectively reduce the amount of computation.

[0031] If 2300≤Re≤4000 (transitional flow state), then multiply the number of sample points by the second adjustment factor 1.2. In this state, the flow is unstable; therefore, appropriately increase the number of sample points to balance the need to capture fluctuations with computational efficiency.

[0032] If Re > 4000 (turbulent state), the number of sample points is multiplied by a third adjustment factor of 1.5. In this state, the intense turbulence inside the pipe will significantly affect the external wind field through the pipe wall, greatly increasing the number of sample points to accurately capture high-frequency turbulence details.

[0033] In this embodiment, =0.72, the calculated Re = 12801.6, which is much greater than 4000, indicating a turbulent state. According to the preset adjustment strategy, the number of sample points is multiplied by the third adjustment factor of 1.5, increasing the number of sample points by 50%. This adjustment ensures accurate capture of the high-frequency turbulent details caused by the intense mixing of fluids within the pipe and the vibration of the pipe wall under turbulent conditions, providing high-precision wind load input for subsequent wind-induced vibration analysis.

[0034] S3. Pulsating wind field synthesis based on harmonic synthesis method The time history of fluctuating wind speed is generated using harmonic synthesis. The specific implementation process is as follows: Spectral model selection: According to the "Code for Wind Resistance Design of Highway Bridges" (JTG / T3360-01-2018), the downwind power spectral density function Su(n) and the vertical power spectral density function Sw(n) are selected as the target spectra, and the Davenport exponential coherence function is used to describe the spatial correlation.

[0035] Matrix decomposition: Based on the selected power spectrum and coherence function, a cross-power spectral density matrix S0(ω) is constructed. Subsequently, this matrix is ​​decomposed using Cholesky decomposition at each frequency point ω1, i.e., S0(ω1) = H(ω1) × H. T ×(ω1), we get the lower triangular matrix H(ω1).

[0036] Time history synthesis: Using the lower triangular matrix H(ω1) and the introduced random phase, the fluctuating wind speed time history u(t) at each spatial point is synthesized using the following formula:

[0037] in, For frequency intervals, for phase angle, Let N be a random phase angle uniformly distributed in the range [0, 2π), where N is the number of frequency components and j is the index of the spatial discrete point.

[0038] S4, Automatic Feedback Verification and Iterative Optimization To ensure the reliability of the simulation results, an automatic feedback verification mechanism is established: Power spectrum calculation and comparison: Fourier transform is performed on the time history of the fluctuating wind speed synthesized in step S3 to calculate the simulated downwind power spectrum P. uu and vertical power spectrum P vv The simulated power spectrum is compared with the standard target power spectrum (Su, Sw) selected in step S3, and the error between the two is calculated.

[0039] Iteration tolerance judgment: preset tolerance range, for example, the error does not exceed 63 on the original scale and does not exceed 1.8 on the logarithmic scale.

[0040] If the error is less than or equal to the tolerance, the simulation result is considered acceptable, and the final wind speed time history and related correlation coefficients are output.

[0041] If the error exceeds the tolerance, the system automatically triggers an iteration: regenerating a set of random phase angles. Then, return to step S3, resynthesize the wind speed time history using the new random phase, and verify it again. This process is repeated until the simulated power spectrum meets the tolerance requirements without manual intervention.

[0042] S5. Results Visualization and Output Ultimately, the pulsed wind speed time history that meets the accuracy requirements will be visualized through a graphical user interface (GUI), including: Plot the time history curves of fluctuating wind speeds in the downwind and vertical directions.

[0043] Plot a comparison diagram between the simulated power spectrum and the standard power spectrum to visually demonstrate the degree of agreement.

[0044] Draw a comparison chart of spatial correlation coefficients.

[0045] Meanwhile, the system supports exporting wind speed time history data in a universal format, which can be directly used in commercial software such as ANSYS and Fluent for subsequent wind-induced vibration response analysis.

[0046] Furthermore, for cases where the main beam undergoes significant deformation under wind load and its own weight, the GUI interface provides a main beam wind speed point height correction function. Users can enable this function, and the system will automatically correct the actual observed height of each wind speed point based on a quadratic function fitting of the influence of gravity and deflection on the main beam's alignment, thereby more realistically simulating the effects of the wind field.

[0047] This embodiment provides a system for simulating fluctuating wind fields in a cable-stayed bridge, specifically including: Parameter input module: Provides a graphical input interface that supports the visual input and real-time modification of wind field parameters, structural parameters, and medium parameters.

[0048] Dynamic adjustment module: The core functions include a Reynolds number calculation unit and a sample point adjustment unit. The Reynolds number calculation unit calculates the Reynolds number based on the input medium parameters and pipe diameter; the sample point adjustment unit dynamically determines the number of sample points for spatial discrete points according to the flow regime range in which the Reynolds number is located, based on a preset adjustment factor.

[0049] Wind field synthesis module: Employing harmonic synthesis, it includes a spectrum model selection unit, a matrix decomposition unit, and a time history synthesis unit. The spectrum model selection unit determines the target power spectrum and coherence function according to specifications; the matrix decomposition unit is responsible for the Cholesky decomposition of the cross-power spectrum matrix; and the time history synthesis unit synthesizes the fluctuating wind speed time history through the superposition of trigonometric series.

[0050] Automatic feedback verification module: This module includes a power spectrum calculation unit and an iterative control unit. The power spectrum calculation unit performs spectral analysis on the synthesized wind speed time history; the iterative control unit is responsible for error assessment and iteration triggering, automatically resynthesizing when the error exceeds the tolerance.

[0051] The results display module provides rich visualization functions, including time-history curve display, power spectrum comparison display, correlation coefficient display, and supports data export. Other embodiments of the invention will be readily apparent to those skilled in the art upon consideration of the specification and practice of the disclosure herein. This invention is intended to cover any variations, uses, or adaptations of the invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not disclosed herein. The specification and embodiments are to be considered exemplary only, and the true scope and spirit of the invention are indicated by the following claims.

[0052] It should be understood that the present invention is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of the invention is limited only by the appended claims.

Claims

1. A method for simulating pulsating wind fields in a cable-stayed bridge, characterized in that, Includes the following steps: S1. Constructing the parameter system Acquire and input wind field parameters, structural parameters of the cable-stayed bridge, and medium parameters of the oil and gas medium inside the pipe; S2, Dynamically adjust the number of sample points Based on the medium parameters and pipe diameter, calculate the Reynolds number Re of the oil and gas inside the pipe; Based on the flow regime range where the Reynolds number Re is located, the number of sample points for spatial discrete points used in pulsating wind field simulation is dynamically adjusted. S3, Synthetic Pulsating Wind Field Based on the adjusted number of sample points, the harmonic synthesis method is used to generate the time history of fluctuating wind speed at each spatial discrete point; S4, Automatic Feedback Verification Calculate the simulated power spectrum corresponding to the synthesized time history of fluctuating wind speed in step S3; The simulated power spectrum is compared with the preset standard power spectrum. If the error exceeds the tolerance range, step S3 is repeated until the error meets the tolerance requirements, and then the final pulsating wind speed time history is output.

2. The method for simulating pulsating wind fields in a cable-stayed bridge according to claim 1, characterized in that, In step S2, the number of sample points is dynamically adjusted according to the Reynolds number Re, specifically including: When the Reynolds number Re < 2300, it is determined to be laminar flow, and the number of sample points is multiplied by a first adjustment factor less than 1; When the Reynolds number is 2300≤Re≤4000, it is determined to be a transient flow, and the number of sample points is multiplied by a second adjustment factor greater than 1; When the Reynolds number Re > 4000, it is determined to be turbulent, and the number of sample points is multiplied by a third adjustment factor that is greater than the second adjustment factor.

3. The method for simulating pulsating wind fields in a cable-stayed bridge according to claim 2, characterized in that, The first adjustment factor is 0.7~0.9, the second adjustment factor is 1.1~1.3, and the third adjustment factor is 1.4~1.

6.

4. The method for simulating pulsating wind fields in a cable-stayed bridge according to claim 1, characterized in that, In step S4, the random phase in the harmonic synthesis method is corrected by iterative correction in order to achieve error convergence between the simulated power spectrum and the standard power spectrum.

5. The method for simulating pulsating wind fields in a cable-stayed bridge according to claim 1, characterized in that, It also includes receiving user-input parameters in real time through a graphical user interface and visually displaying the time history of the pulsating wind speed, the comparison results of the simulated power spectrum, and the correlation coefficient.

6. The method for simulating pulsating wind fields in a cable-stayed bridge according to claim 5, characterized in that, The graphical user interface also supports the correction of the height of the wind speed point of the main beam, which is based on a quadratic function fitting of the influence of gravity and deflection on the height.

7. A system for simulating fluctuating wind fields in a cable-stayed bridge, used to implement the method as described in any one of claims 1-6, characterized in that, The system includes: The parameter input module is used to receive wind field parameters, structural parameters, and medium parameters input by the user. The dynamic adjustment module is used to calculate the Reynolds number of oil and gas in the pipe and dynamically determine the number of sample points for spatial discrete points based on the Reynolds number. The wind field synthesis module is used to synthesize the time history of pulsating wind speed based on the harmonic synthesis method and the number of sample points determined by the dynamic adjustment module. An automatic feedback verification module is used to compare the simulated power spectrum of the synthesized wind field with the standard power spectrum, and control the wind field synthesis module to resynthesize when the error exceeds the tolerance until the error meets the requirements. The results display module is used to output and visualize the final pulsed wind speed time history and related comparison charts.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the program is executed by the processor, it implements the method for simulating the pulsating wind field of a cable-stayed bridge as described in any one of claims 1-6.

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