A vibration prediction method for the wind tunnel model support system based on fluid-structure interaction analysis

Abstract

A vibration prediction method for a wind tunnel model support system based on fluid-structure interaction analysis belongs to the field of active vibration control of aircraft models. First, a structural finite element model of the wind tunnel model support system is established based on its three-dimensional characteristics of the support system and the flow field. Secondly, in the fluid domain, the k-epsilon turbulence calculation method is combined to simulate the wind tunnel flow field environment, and the fluid stress and displacement are obtained through fluid dynamics analysis, and then the aerodynamic load of the flow field acting on the solid domain is obtained. Then, in the solid domain, the solid stress and deformation are obtained through transient dynamics analysis. Finally, considering the fluid-structure two-phase coupling effect, combined with the fluid-structure coupling control equation and Fourier transform, the time-domain and frequency-domain vibration responses of the wind tunnel model support system are obtained, and the vibration response prediction of the model support system is realized. The present invention can predict the vibration of the model support system by numerical simulation without conducting wind tunnel tests, avoid risks during the test process, can predict vibrations at different wind speeds and different angles of attack, has high calculation accuracy and good effectiveness, and provides a good basis for the vibration control of the model support system.

Description

Technical Field

[0001] The present invention belongs to the field of active vibration control of aircraft models, and relates to a vibration prediction method for a wind tunnel model support system based on fluid-structure interaction analysis. Background Art

[0002] Wind tunnel tests are an important means to understand the performance of aircraft and obtain aerodynamic data of aircraft. They can greatly reduce the development risks and costs and have become a key link in the R & D process of various aerospace aircraft. Wind tunnel models often adopt the tail support method, which has the characteristics of simple structure and small interference to the flow field, and is widely used in wind tunnel tests. The tail support system of the wind tunnel model is successively connected by a strut, a wind tunnel balance, and a wind tunnel model, forming a cantilever-like structure, showing dynamic characteristics of low stiffness and small damping. It is prone to large-amplitude vibrations under continuous excitation of wind loads or even extreme conditions such as large angles of attack and near stall, seriously affecting the acquisition of test data and even posing a risk of damage to the support structure. Therefore, it is necessary to suppress the vibration of the system.

[0003] However, the external flow field environment of the wind tunnel is complex, and the fluid-structure interaction between the model support system and the broadband aerodynamic load makes it difficult to understand the vibration mechanism of the model support system. Therefore, before designing the vibration suppression system, it is necessary to study the vibration prediction method of the wind tunnel model support system, clarify its vibration mechanism, obtain the vibration response characteristics of the system, and then guide the structural layout of the vibration suppression system and the design of the vibration control algorithm to improve the vibration suppression ability of the vibration suppression system.

[0004] Vibration prediction methods based on fluid-structure interaction technology, with the advantages of fine models and high calculation accuracy, have been widely used in fields such as vibration prediction of pipeline valves and vibration prediction of ship shafting. Lin Zhe et al. from Zhejiang Sci-Tech University published a patent "A Butterfly Valve Vibration Prediction Method Based on Fluid-Structure Interaction Analysis" with the patent number 202110965185.X in 2021. First, the natural frequency of the butterfly plate of the butterfly valve was obtained through static modal analysis, then the vortex shedding frequency of the liquid flowing through the butterfly plate was obtained based on numerical calculation of the fluid-structure interaction method, and finally, by comparing the natural frequency and the vortex shedding frequency, the resonance occurrence interval of the butterfly plate under complex conditions was predicted; Li Wanyou et al. from Harbin Engineering University published a patent "A Two-Way Fluid-Structure Interaction Numerical Simulation Method for a Propeller-Shaft Coupling System" with the patent number 202211399807.8 in 2022. In the vibration prediction of the propeller-shaft system, first, a numerical calculation model of the propeller flow field and the shafting dynamics was established, then the flow field solver was imported through a secondary development program, and finally, it was compiled to realize the two-way coupling calculation of the flow field and the structure field, that is, the two-way fluid-structure interaction numerical simulation of the propeller-shaft coupling system, so as to obtain the excitation force of the propeller flow field and the vibration displacement, velocity, and acceleration results of the shafting in real time. However, the above methods are all based on the solution of the liquid flow field, with high density and slow flow velocity, and cannot be applied to the high-speed and low-density flow field of the wind tunnel.

[0005] At the same time, the fluid-structure interaction technology is rarely applied in the field of vibration prediction of the wind tunnel model support system. At present, the vibration of the wind tunnel model support system is generally predicted based on the modal analysis of the solid domain and the transient dynamics method. In the paper "Simulation of Active Vibration Control of a Piezoelectric Component Embedded Wind Tunnel Model Support System" published by Nie Xutao et al. of China Aerodynamics Research and Development Center in 2014, combined with the mechanical system dynamics analysis software, based on the rigid-flexible coupling dynamics theory, a structural vibration simulation model of the wind tunnel model support system was established to realize the analysis and prediction of the system vibration characteristics. However, it regarded the environment as a vacuum and did not consider the fluid-structure coupling effect of the flow field aerodynamic load, and there was a deviation between the obtained vibration prediction result and the wind tunnel test result. Therefore, considering the fluid-structure coupling effect in the test process, establishing finite element models of the fluid domain and the solid domain, and performing coupled vibration analysis are expected to become an effective method for realizing the vibration prediction of the wind tunnel model support system. Summary of the Invention

[0006] The present invention overcomes the deficiencies of the existing methods and proposes a vibration prediction method for a wind tunnel model support system based on fluid-structure coupling analysis. This method considers the coupling effect that the fluid load acts on the solid to generate deformation, and the solid deformation reacts to change the fluid motion state. Combining the fluid-structure coupling control equation, the vibration of the wind tunnel model support system is predicted by numerical simulation means, and a more accurate vibration response of the model support system can be obtained. This method can achieve accurate vibration prediction under multiple working conditions and postures, providing strong support for the design of the vibration suppression system.

[0007] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0008] A vibration prediction method for a wind tunnel model support system based on fluid-structure coupling analysis. This method first establishes its structural finite element model based on the three-dimensional characteristics of the wind tunnel model support system and the flow field. Secondly, in the fluid domain, combined with the Standard k-epsilon turbulence calculation method, parameters such as the flow field pressure and flow velocity are set to accurately simulate the wind tunnel flow field environment. Through fluid dynamics analysis, the fluid stress and displacement are obtained, and then the flow field aerodynamic load acting on the solid domain by the fluid is obtained. Then, in the solid domain, the solid stress and deformation are obtained through transient dynamics analysis. Finally, considering the coupling effect that the fluid load acts on the solid to generate deformation, and the solid deformation reacts to change the fluid motion state, combined with the fluid-structure interaction (FSI) control equation, two-way data transfer between the two systems is realized, and then the time-domain vibration response of the wind tunnel model support system is obtained. Further, based on the Fourier transform, the natural frequency of the model support system is obtained, and the frequency-domain vibration response of the model support system is obtained. It should be particularly noted that this method considers the coupling effect that the fluid load acts on the solid to generate deformation, and the solid deformation reacts to change the fluid motion state. Combining the FSI control equation, a more accurate vibration response of the model support system can be obtained. Figure 1The flowchart of the vibration prediction method for the wind tunnel model support system based on fluid-structure interaction analysis provided by the present invention is as follows. The specific steps of the method are as follows:

[0009] Step 1: Select a typical wind tunnel test model, and construct finite element models of the solid domain and the fluid domain according to its three-dimensional characteristics of the model support system and the wind tunnel flow field respectively for subsequent simulation analysis. Among them, when constructing the finite element models of the fluid domain and the solid domain, by changing the arrangement angle of the model support system in the flow field (0 to 30 degrees), the vibration conditions of the model support system at different angles of attack are predicted.

[0010] Step 2: Conduct transient fluid dynamics analysis on the flow field in the fluid domain. Based on the Standard k-epsilon turbulence calculation model, set the inlet flow velocity and outlet pressure of the wind tunnel flow field and the roughness of the wind tunnel wall surface to simulate the wind tunnel flow field environment, obtain the stress and displacement of the fluid domain, and further obtain the aerodynamic load of the flow field acting on the solid domain. Specifically as follows:

[0011] Step 2.1: Preprocess the finite element model of the fluid domain, cut off the part of the model support system in the flow field, create the inlet and outlet cross-sections and boundary cross-sections of the wind tunnel flow field, create the interface between the wind tunnel flow field and the model support system as the fluid domain coupling surface, and divide the fluid domain mesh, including the fluid domain coupling surface mesh and other meshes.

[0012] Step 2.2: Import the fluid domain mesh divided in Step 2.1 into the Fluent module of the Workbench software. Based on the Standard k-epsilon turbulence calculation model, use a pressure-based solver and conduct transient simulation of the fluid domain based on the absolute velocity equation. Set the inlet flow velocity, outlet pressure of the wind tunnel flow field and the roughness of the wind tunnel wall surface as the boundary conditions of the wind tunnel flow field to simulate the actual state of the wind tunnel flow field. Among them, when setting the inlet flow velocity of the wind tunnel flow field, by adjusting different inlet flow velocities (0.5 Mach to 3 Mach), the vibration of the model support system at different wind speeds is predicted.

[0013] The Standard k-epsilon turbulence calculation model can simulate the fully turbulent flow process in the wind tunnel flow field, and thus better simulate the actual flow field. This calculation model is shown in Formulas (1) to (2):

[0014]

[0015]

[0016] In the formula, ρ represents the fluid density; K represents the fluid turbulent kinetic energy density; ε represents the fluid turbulent dissipation rate; μ represents the viscosity coefficient; μ t represents the eddy viscosity coefficient, which is a function of K and ε, and is expressed as t represents time; G k represents the production term of turbulent kinetic energy caused by the average velocity gradient, expressed as represents the mean value of the velocity components in the i and j directions; x i ,x j represents the instantaneous coordinates in the i and j directions; μ represents the viscosity coefficient; C ε1 , C ε2 , C μ are empirical constants, Pr K , Pr ε are the Prandtl numbers of turbulent kinetic energy and dissipation rate respectively.

[0017] Step 2.3, Set up dynamic meshes on the fluid domain coupling surface created in Step 2.1 to achieve the change of the flow field mesh over time; Divide each second into several time steps in the transient simulation of the fluid domain, and obtain the fluid domain stress and displacement through iterative calculation, and then obtain the aerodynamic load of the flow field acting on the solid domain.

[0018] Step 3, In the solid domain, perform transient dynamic analysis to obtain the stress and deformation of the model support system; Specifically as follows:

[0019] Step 3.1, Mesh the finite element model of the solid domain established in Step 1 to ensure that the surface mesh of the solid domain is the same size as the mesh of the fluid domain coupling surface divided in Step 2.1; Import the mesh of the solid domain into the Transient Structural module of Workbench software for transient simulation of the solid domain.

[0020] Step 3.2, In the actual wind tunnel test, the slender strut of the wind tunnel model support system is fixed to the machete, which is simplified to a fixed support at the end of the slender strut; Create a solid domain coupling surface on the surface of the model support system, and apply the aerodynamic load of the flow field acting on the solid domain obtained in Step 2.3 on the solid domain coupling surface. Divide each second into several time steps in the transient simulation of the solid domain, and obtain the stress and deformation of the model support system under the action of the aerodynamic load of the flow field through iterative calculation.

[0021] Step 4: Through the System Coupling module of Workbench software, create a two-way data exchange between the fluid domain coupling surface and the solid domain coupling surface based on the interpolation method to achieve fluid-structure interaction (FSI) solution, that is, the aerodynamic load of the flow field is applied to the solid domain to generate deformation, and the deformation of the solid domain in turn changes the motion state of the flow field, thereby changing the effect of the aerodynamic load of the flow field. The FSI solution process is based on the FSI control equation, which consists of three parts: the fluid control equation, the solid control equation, and the fluid-structure control equation. The fluid control equation includes the mass control equation shown in Equation (3) and the momentum control equation shown in Equation (4). The solid control equation is shown in Equation (5), and the fluid-structure control equation is shown in Equation (6). Since there is no heat exchange problem in the vibration problem of the wind tunnel model support system, the energy equation is ignored.

[0022]

[0023] In the formula, t is time; ρ f is the fluid density; v is the fluid velocity vector.

[0024]

[0025] In the formula, T f is the fluid shear stress tensor; f f is the fluid body force vector.

[0026]

[0027] In the formula, ρ s is the solid density; σ s is the solid Cauchy stress tensor; f s is the solid body force vector; is the acceleration of the solid domain element.

[0028]

[0029] In the formula, τ f and τ s are the fluid and solid stresses respectively; n f and n s are the fluid and solid unit direction vectors respectively; d f and d s are the fluid displacement and solid deformation respectively.

[0030] When the data of the fluid domain and the solid domain are transferred between the coupling surfaces, it is necessary to satisfy the principle of stress and displacement equality or conservation, and thus perform fluid-structure interaction solution to obtain the flow field pressure and velocity distribution in the fluid domain and the displacement and acceleration results of the wind tunnel model support system in the solid domain under the time domain.

[0031] Step 5: Extract the fluid-structure interaction solution results obtained in Step 4, export the acceleration data at the centroid of the wind tunnel model, plot the time-domain acceleration curve of the wind tunnel model support system, and based on this time-domain acceleration curve, observe the vibration of the wind tunnel model support system under the aerodynamic load of the flow field, so as to realize the prediction of the time-domain vibration response.

[0032] Step 6: Process the acceleration data obtained in Step 5 through Fourier transform to obtain the acceleration spectrum, extract the frequencies of the first n peak points (considering that the vibration energy of high-order modes is small and the influence on the system can be ignored, generally n is taken not to be greater than 4), that is, the first n natural frequencies of the model support system, so as to realize the prediction of the frequency-domain vibration response.

[0033] The beneficial effects of the present invention are as follows:

[0034] (1) Compared with the traditional vibration prediction method that does not consider the coupling vibration effect and has errors in the obtained results, the method proposed by the present invention analyzes the transient processes of the fluid domain and the solid domain through the finite element method, and combines the fluid-structure interaction analysis method to process the coupling vibration effect, which can accurately predict the fluid-structure interaction vibration response of the model support system under the aerodynamic load of the flow field, extract the natural frequencies of the model support system, obtain the vibration response characteristics of the system, and maximize the vibration control ability.

[0035] (2) In addition, compared with the traditional vibration prediction method for the wind tunnel model support system, the present invention can predict the vibration of the model support system through numerical simulation without conducting wind tunnel tests, avoid risks during the test process, can perform vibration prediction under different wind speeds and different angles of attack, has high calculation accuracy and good effectiveness, and provides a good basis for the vibration control of the model support system. Description of the Drawings

[0036] Figure 1 It is a flowchart of the vibration prediction of the wind tunnel model support system of the present invention.

[0037] Figure 2 It is a fluid domain mesh model diagram applying the present invention.

[0038] Figure 3 It is a time-domain acceleration response curve of the model support system applying the present invention.

[0039] Figure 4 It is an acceleration spectrum of the model support system applying the present invention. Detailed Embodiments

[0040] To better illustrate the purpose and advantages of the present invention, the content of the invention will be further described below in conjunction with the drawings and examples.

[0041] A vibration prediction method for a wind tunnel model support system based on fluid-structure interaction analysis, the flowchart is as Figure 1, the specific steps of the method are as follows:

[0042] 1) Taking the flying wing layout simplified mass block as an example wind tunnel model, respectively constructing finite element models of the fluid domain and the solid domain based on the model support system and the three-dimensional characteristics of the wind tunnel flow field, horizontally arranging the model support system in the flow field, and performing vibration prediction when the wind tunnel model is at an angle of attack of 0 degrees;

[0043] 2) Preprocessing the finite element model of the fluid domain, cutting off the part of the model support system from the flow field, defining the inlet, outlet and boundary sections of the wind tunnel flow field, creating the fluid domain coupling surface at the interface between the wind tunnel flow field and the wind tunnel model support system, dividing the fluid domain grid with a coupling surface grid size of 2.5 mm and the remaining part of 10 mm, and the created fluid domain grid model is as Figure 2 shown.

[0044] 3) Importing the fluid domain grid divided in step 2) into the Fluent module of the Workbench software, according to the Standard k-epsilon turbulence calculation model, using a pressure-based solver and performing transient simulation of the fluid domain based on the absolute velocity equation, carrying out transient simulation of the fluid domain under the condition of a wind tunnel wind speed of 2 Mach, setting the inlet velocity of the fluid domain to 2 Mach, the outlet pressure to standard atmospheric pressure, and the wind tunnel wall roughness to smooth, simulating the actual wind tunnel flow field environment, where the Standard k-epsilon turbulence calculation model is as shown in formulas (1) to (2).

[0045] Creating a dynamic mesh for the fluid domain on the fluid domain coupling surface created in step 2) to realize the change of the fluid domain grid with time, dividing each second into 200 time steps in the transient simulation of the fluid domain, and obtaining the stress and displacement of the fluid domain through iterative calculation, and then obtaining the aerodynamic load of the flow field acting on the solid domain.

[0046] 4) Dividing the solid domain grid of the solid domain finite element model established in step 1) with a grid size of 2.5 mm to ensure that the surface grid of the solid domain is consistent with the grid size of the fluid domain coupling surface created in step 2); importing the solid domain grid into the Transient Structural module of the Workbench software to perform transient simulation of the solid domain; simplifying the boundary conditions of the wind tunnel model support system to the fixed support at the end of the slender strut, creating a solid domain coupling surface on the surface of the model support system, and applying the aerodynamic load of the flow field acting on the solid domain obtained in step 3) on the coupling surface. Dividing each second into 200 time steps in the transient simulation of the solid domain, and obtaining the deformation and stress of the model support system under the action of the aerodynamic load of the flow field through iterative calculation.

[0047] 5) Create a two-way data exchange between the fluid domain and the solid domain coupling surface based on the interpolation method in the System Coupling module of the Workbench software, and realize the coupling effect that the aerodynamic load in the flow field acts on the solid domain to generate deformation and the deformation reaction of the solid domain changes the fluid motion state. Based on the FSI control equations, that is, formulas (3) to (6), perform fluid-structure interaction (FSI) solution to obtain the flow field pressure and velocity distribution in the fluid domain and the displacement and acceleration results of the wind tunnel model support system in the solid domain under the time domain.

[0048] 6) Extract the fluid-structure interaction solution results obtained in step 5), export the acceleration data at the centroid of the wind tunnel model, and plot the time-domain acceleration curve of the model vibration system as Figure 3 shown. Under the action of the aerodynamic load, the model support system initially generates large-amplitude vibrations, and the acceleration approaches 0 after about 3 s. The vibration of the model support system tends to be stable, realizing the prediction of the time-domain vibration response of the model support system.

[0049] 7) Process the acceleration data obtained in step 6) through Fourier transform to obtain the frequency spectrum of the model support system, as Figure 4 shown. Extract the first two peak points of the frequency spectrum. It is obtained that the first natural frequency of the model vibration system in this embodiment under the action of the aerodynamic load is about 6 Hz, and the second natural frequency is about 60 Hz, which is consistent with the actual test results, realizing the prediction of the frequency-domain vibration response of the model support system. It can be considered that this method can better predict the vibration response of the model support system.

[0050] The above-described embodiments only represent the implementation manners of the present invention, but should not be construed as limiting the scope of the present invention patent. It should be noted that for those skilled in the art, without departing from the concept of the present invention, several deformations and improvements can be made, and these all belong to the protection scope of the present invention.

Claims

1. A vibration prediction method for a wind tunnel model support system based on fluid-structure interaction analysis, characterized in that, The vibration prediction method for the wind tunnel model support system includes the following steps: Step 1: Select a typical wind tunnel test model and construct finite element models for the solid domain and the fluid domain according to its three-dimensional characteristics of the model support system and the wind tunnel flow field respectively; Step 2: Conduct transient fluid dynamics analysis on the flow field in the fluid domain. Based on the Standard k-epsilon turbulence calculation model, set the inlet flow velocity and outlet pressure of the wind tunnel flow field and the roughness of the wind tunnel wall surface to simulate the wind tunnel flow field environment, obtain the stress and displacement of the fluid domain, and further obtain the aerodynamic load of the flow field acting on the solid domain; Step 3: In the solid domain, conduct transient dynamics analysis to obtain the stress and deformation of the model support system; Step 4: Through the System Coupling module of Workbench software, create two-way data exchange between the coupling surface of the fluid domain and the coupling surface of the solid domain based on the interpolation method to achieve fluid-structure interaction solution, and obtain the pressure and velocity distribution of the flow field in the fluid domain and the displacement and acceleration results of the wind tunnel model support system in the solid domain in the time domain; Step 5: Extract the fluid-structure interaction solution results obtained in Step 4, export the acceleration data at the centroid of the wind tunnel model, draw the time-domain acceleration curve of the wind tunnel model support system, and observe the vibration of the wind tunnel model support system under the aerodynamic load of the flow field based on this time-domain acceleration curve, so as to realize the prediction of the time-domain vibration response; Step 6: Process the acceleration data obtained in Step 5 through Fourier transform to obtain the acceleration spectrum, extract the frequencies of the first n peak points, that is, the first n natural frequencies of the model support system, to realize the prediction of the frequency-domain vibration response.

2. The vibration prediction method for a wind tunnel model support system based on fluid-structure interaction analysis according to claim 1, characterized in that, In Step 1, when constructing the finite element models of the solid domain and the fluid domain, by changing the arrangement angle of the model support system in the flow field, the vibration of the model support system under different angles of attack is predicted.

3. The vibration prediction method for a wind tunnel model support system based on fluid-structure interaction analysis according to claim 1, characterized in that, The specific content of Step 2 is as follows: Step 2.1: Preprocess the finite element model of the fluid domain, create the interface between the wind tunnel flow field and the model support system as the coupling surface of the fluid domain, and divide the fluid domain grid, including the grid of the coupling surface of the fluid domain and other grids; Step 2.2: Import the fluid domain grid divided in Step 2.1 into the Fluent module of Workbench software. According to the Standard k-epsilon turbulence calculation model, use a pressure-based solver and conduct transient simulation of the fluid domain based on the absolute velocity equation. Set the inlet flow velocity, outlet pressure of the wind tunnel flow field and the roughness of the wind tunnel wall surface as the boundary conditions of the wind tunnel flow field to simulate the actual state of the wind tunnel flow field; Step 2.3: Set dynamic grids on the coupling surface of the fluid domain created in Step 2.1 to realize the change of the flow field grid with time; divide each second into several time steps in the transient simulation of the fluid domain, and obtain the stress and displacement of the fluid domain through iterative calculation, and further obtain the aerodynamic load of the flow field acting on the solid domain.

4. The vibration prediction method for a wind tunnel model support system based on fluid-structure interaction analysis according to claim 3, characterized in that, In Step 2.1, the preprocessing of the finite element model of the fluid domain includes: cutting off the part of the model support system in the flow field, and creating the inlet and outlet cross-sections and boundary cross-sections of the wind tunnel flow field.

5. The vibration prediction method for a wind tunnel model support system based on fluid-structure interaction analysis according to claim 3, characterized in that, In step 2.2, when setting the inlet velocity of the wind tunnel flow field, the vibration of the model support system at different wind speeds is predicted by adjusting different inlet velocities.

6. The vibration prediction method for a wind tunnel model support system based on fluid-structure interaction analysis according to claim 3, characterized in that, In step 2.2, the Standard k-epsilon turbulence calculation model is shown as in formulas (1) to (2): Where ρ represents the fluid density; K represents the turbulent kinetic energy density of the fluid; ε represents the turbulent kinetic energy dissipation rate of the fluid; μ represents the viscosity coefficient; μ t represents the eddy viscosity coefficient, which is a function of K and ε and is expressed as t represents time; G k represents the generation term of turbulent kinetic energy caused by the mean velocity gradient and is expressed as represents the time-averaged values of the velocity components in the i and j directions; x i ,x j represents the instantaneous coordinates in the i and j directions; μ represents the viscosity coefficient; C ε1 , C ε2 , C μ are empirical constants, Pr K , Pr ε are the Prandtl numbers of turbulent kinetic energy and dissipation rate, respectively.

7. The vibration prediction method for a wind tunnel model support system based on fluid-structure interaction analysis according to claim 3, characterized in that, The specific steps of step 3 are as follows: Step 3.1: Mesh the finite element model of the solid domain established in step 1, where the mesh of the solid domain is the same size as the mesh of the fluid domain coupling surface divided in step 2.1; Import the mesh of the solid domain into the Transient Structural module of Workbench software for transient simulation of the solid domain; Step 3.2: Simplify the wind tunnel model support system into a fixed support at the end of a slender strut; Create a solid domain coupling surface on the surface of the model support system, and apply the aerodynamic load of the flow field acting on the solid domain obtained in step 2.3 to the solid domain coupling surface; Divide each second into several time steps in the transient simulation of the solid domain, and obtain the stress and deformation of the model support system under the action of the aerodynamic load of the flow field through iterative calculation.

8. The vibration prediction method for a wind tunnel model support system based on fluid-structure interaction analysis according to claim 1, characterized in that, In step 4, the fluid-structure interaction solution process is based on the FSI control equation, which consists of three parts: the fluid control equation, the solid control equation, and the fluid-structure control equation. The fluid control equation includes the mass control equation shown as in formula (3) and the momentum control equation shown as in formula (4), the solid control equation is shown as in formula (5), and the fluid-structure control equation is shown as in formula (6): where t is time; ρ f is the fluid density; v is the fluid velocity vector; where T f is the fluid shear stress tensor; f f is the fluid body force vector; where ρ s is the solid density; σ s is the solid Cauchy stress tensor; f s is the solid body force vector; is the acceleration of the solid domain element; where τ f and τ s are the fluid and solid stresses respectively; n f and n s are the fluid and solid unit direction vectors respectively; d f and d s are the fluid displacement and solid deformation respectively.

9. A vibration prediction method for a wind tunnel model support system based on fluid-structure interaction analysis according to claim 1, wherein, In step 6, n is not greater than 4.

Images