Method and device for calculating vibration and noise of flow-induced cylindrical shell structure

Abstract

The application provides a flow-induced cylindrical shell structure vibration noise calculation method and device, which comprises the following steps: determining the turbulent boundary layer parameters of the surface of the cylindrical shell structure according to the geometric model and flow field information of the cylindrical shell structure, and substituting the turbulent boundary layer parameters into the empirical model of the mutual power spectrum of the turbulent boundary layer wall surface fluctuating pressure and performing convolution with the Dirac comb function to obtain the mutual power spectrum function of the cylindrical surface; adopting the non-correlated wall surface pressure spiral wave technology and substituting the mutual power spectrum function of the cylindrical surface to obtain the equivalent synthetic wall surface pressure field of the cylindrical surface; dividing the structure grid and the acoustic grid according to the geometric model of the cylindrical shell structure, and establishing a fluid-solid coupling finite element model; loading the equivalent synthetic wall surface pressure field of the cylindrical surface to the surface of the cylindrical shell as the surface excitation for finite element solving to obtain the vibration and sound radiation of the cylindrical shell structure as the vibration noise result. The application realizes a hybrid numerical method based on the non-correlated wall surface pressure spiral wave technology.

Description

Technical Field

[0001] This invention relates to the field of structural vibration and noise analysis technology, and in particular to a method and apparatus for calculating the vibration and noise of a flow-induced cylindrical shell structure. Background Technology

[0002] During underwater vehicle navigation, a turbulent boundary layer is generated on the structural surface. This turbulent boundary layer not only directly radiates noise but also excites structural vibrations, thus generating flow-induced noise. As the speed increases, flow-induced noise becomes one of the most significant sources of radiated noise from the structure, severely impacting passenger comfort and the acoustic performance of the vehicle. Therefore, researching methods for quickly, efficiently, and accurately solving for structural flow-induced vibrations and noise is of significant engineering importance.

[0003] A review of relevant domestic and international literature reveals that researchers have conducted extensive studies on turbulent-induced structural vibration and noise. For simple models like flat plates, researchers have established analytical and numerical models and validated them through experiments. In numerical methods, some scholars have applied uncorrelated wall pressure plane wave techniques to solve for the flow-induced vibration and noise of flat plates. However, for cylindrical shell models, due to their higher complexity, analytical methods are extremely difficult to apply. Furthermore, the numerical method for uncorrelated wall pressure waves lacks application in cylindrical shell structures. Therefore, this invention applies this method to cylindrical shell structures, filling a gap in existing methods. Summary of the Invention

[0004] This invention provides a method and apparatus for calculating the vibration and noise of a flow-induced cylindrical shell structure, which addresses the shortcomings of existing technologies in solving the flow-induced vibration and noise of cylindrical shell models. It realizes a hybrid numerical method based on uncorrelated wall pressure helical wave technology, transforming the stochastic analysis problem of vibration and noise of cylindrical shell structures under turbulent boundary layer excitation into a deterministic problem, thereby improving the feasibility and efficiency of solving the problem using finite element software.

[0005] This invention provides a method for calculating the vibration noise of a flow-induced cylindrical shell structure, comprising:

[0006] Based on the geometric model and flow field information of the cylindrical shell structure, the turbulent boundary layer parameters on the surface of the cylindrical shell structure are determined. The turbulent boundary layer parameters are then substituted into the empirical model of the cross power spectrum of the fluctuating pressure of the turbulent boundary layer wall of the flat plate and convolved with the Dirac comb function to obtain the cross power spectrum function of the fluctuating pressure of the turbulent boundary layer of the cylindrical surface.

[0007] By employing the uncorrelated wall pressure spiral wave technique and substituting the cross power spectrum function of the fluctuating pressure of the turbulent boundary layer on the cylindrical surface, the equivalent synthetic wall pressure field of the cylindrical surface is obtained.

[0008] Based on the geometric model of the cylindrical shell structure, structural mesh and acoustic mesh are divided. Based on the structural mesh and acoustic mesh, a fluid-structure interaction finite element model of the cylindrical shell structure is established using the finite element method, and corresponding boundary conditions are applied.

[0009] The equivalent composite wall pressure field of the cylindrical surface is applied to the surface of the cylindrical shell in the fluid-structure interaction finite element model as a surface excitation for finite element solution, and the vibration and sound radiation of the cylindrical shell structure are obtained as vibration noise results.

[0010] According to the present invention, a method for calculating the vibration noise of a flow-induced cylindrical shell structure is provided. This method employs uncorrelated wall pressure helical wave technology and substitutes the cross-power spectrum function of the fluctuating pressure in the turbulent boundary layer of the cylindrical surface to obtain the equivalent synthetic wall pressure field of the cylindrical surface, including:

[0011] By changing the random phase factor of the uncorrelated wall pressure spiral wave, multiple sets of different equivalent composite wall pressure fields are obtained on the cylindrical surface, which serve as the input load for the finite element method.

[0012] According to the present invention, a method for calculating the vibration and noise of a flow-induced cylindrical shell structure is provided, wherein the equivalent composite wall pressure field of the cylindrical surface is applied to the surface of the cylindrical shell in the fluid-structure interaction finite element model as a surface excitation for finite element solution, and the vibration and sound radiation of the cylindrical shell structure are obtained, including:

[0013] Each set of equivalent composite wall pressure fields of the cylindrical surface is applied to the surface of the cylindrical shell in the fluid-structure interaction finite element model as a surface excitation for finite element solution, and the vibration and acoustic radiation of the cylindrical shell structure are obtained.

[0014] The average vibration of the multiple sets of vibrations and the average acoustic radiation of the multiple sets of acoustic radiations of the cylindrical shell structure are taken as the final vibration noise result of the cylindrical shell structure excited by the turbulent boundary layer.

[0015] According to the present invention, a method for calculating the vibration noise of a flow-induced cylindrical shell structure is provided. The cross-power spectrum function of the turbulent boundary layer pressure on a flat plate is obtained by substituting the turbulent boundary layer parameters into the empirical model of the cross-power spectrum of the fluctuating pressure on the wall of the turbulent boundary layer using the following formula and then convolving it with the Dirac comb function:

[0016]

[0017] in, This is the cross-power spectral function of the fluctuating pressure in the turbulent boundary layer of a cylindrical surface. For the empirical model of the cross-power spectrum of fluctuating pressure on the wall of a flat plate turbulent boundary layer, the period of the Dirac comb function is... R is the radius of the cylindrical shell structure, and M represents the comb function. The relative distance between two points in terms of flow direction (axial direction). The spanwise (circumferential) relative distance between two points. It is the angular frequency.

[0018] According to the present invention, a method for calculating the vibration noise of a flow-induced cylindrical shell structure is provided. The method substitutes the cross-power spectrum function of the fluctuating pressure of the turbulent boundary layer on the cylindrical surface into the uncorrelated wall pressure helical wave to obtain the equivalent synthetic wall pressure field of the cylindrical surface, including:

[0019] The cross-power spectrum function of the fluctuating pressure in the turbulent boundary layer of the cylindrical surface is subjected to Fourier transform to obtain the frequency wavenumber spectrum function of the fluctuating pressure in the turbulent boundary layer of the cylindrical surface.

[0020] The equivalent composite wall pressure field of the cylindrical surface is determined based on the frequency wavenumber spectrum function of the fluctuating pressure in the turbulent boundary layer of the cylindrical surface.

[0021] According to the present invention, a method for calculating the vibration noise of a flow-induced cylindrical shell structure is provided. The equivalent composite wall pressure field of the cylindrical surface is determined using the following formula based on the frequency wavenumber spectrum function of the fluctuating pressure in the turbulent boundary layer of the cylindrical surface:

[0022]

[0023] in, For the s-th group of equivalent composite wall pressure fields, Let R be the coordinates of the i-th point on the cylindrical surface, and R be the radius of the cylindrical shell structure. The wave number in the s-th group is The phase of the spiral wave is in [0, A random phase factor distributed within the range. The frequency wavenumber spectrum function of the fluctuating pressure in the turbulent boundary layer of the cylindrical surface is given. It is the boundary layer thickness. Where P is the angular frequency, Q is the number of wavenumber samples in the flow direction (axial direction), and j is the imaginary unit. denoted as axial wavenumber and n as circumferential wavenumber.

[0024] According to the present invention, a method for calculating the vibration noise of a flow-induced cylindrical shell structure is provided, wherein the turbulent boundary layer parameters include migration velocity, empirical constants of flow direction and spanwise direction, boundary layer thickness, and Reynolds number.

[0025] The present invention also provides a device for calculating the vibration noise of a flow-induced cylindrical shell structure, comprising:

[0026] The convolution module is used to determine the turbulent boundary layer parameters of the cylindrical shell structure surface based on the geometric model and flow field information of the cylindrical shell structure, and then to convolve the turbulent boundary layer parameters into the empirical model of the cross power spectrum of the fluctuating pressure of the turbulent boundary layer wall of the flat plate with the Dirac comb function to obtain the cross power spectrum function of the fluctuating pressure of the turbulent boundary layer of the cylindrical surface.

[0027] The acquisition module is used to obtain the equivalent synthetic wall pressure field of the cylindrical surface by using the uncorrelated wall pressure spiral wave technology and substituting the cross power spectrum function of the turbulent boundary layer pulsating pressure of the cylindrical surface.

[0028] The module is used to divide the structural mesh and acoustic mesh according to the geometric model of the cylindrical shell structure, establish the fluid-structure interaction finite element model of the cylindrical shell structure using the finite element method based on the structural mesh and acoustic mesh, and apply the corresponding boundary conditions.

[0029] The solver module is used to apply the equivalent composite wall pressure field of the cylindrical surface to the cylindrical shell surface in the fluid-structure interaction finite element model as a surface excitation for finite element solution, and obtain the vibration and sound radiation of the cylindrical shell structure as vibration noise results.

[0030] The present invention also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the flow-induced cylindrical shell structure vibration noise calculation method as described above.

[0031] The present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the method for calculating the vibration noise of a flow-induced cylindrical shell structure as described above.

[0032] The present invention also provides a computer program product, including a computer program that, when executed by a processor, implements the flow-induced cylindrical shell structure vibration noise calculation method as described above.

[0033] The present invention provides a method and apparatus for calculating the vibration and noise of a flow-induced cylindrical shell structure. By substituting the turbulent boundary layer parameters into the empirical model of the cross-power spectrum of the fluctuating pressure on the wall of a flat plate turbulent boundary layer and convolving it with the Dirac comb function, the cross-power spectrum function of the fluctuating pressure of the turbulent boundary layer on the cylindrical surface is obtained. Based on the uncorrelated wall pressure spiral wave technique, the cross-power spectrum function of the fluctuating pressure of the turbulent boundary layer on the cylindrical surface is substituted to obtain the equivalent synthetic wall pressure field of the cylindrical surface. Thus, the expression of the fluctuating pressure of the turbulent boundary layer on the cylindrical shell surface is transformed from the original frequency wavenumber spectrum into a deterministic pressure expression. In other words, the stochastic analysis problem of the vibration and noise of a cylindrical shell structure under turbulent boundary layer excitation is transformed into a deterministic problem, which improves the feasibility and efficiency of solving using finite element software. Attached Figure Description

[0034] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0035] Figure 1 This is one of the flowcharts illustrating the method for calculating vibration noise of a flow-induced cylindrical shell structure provided by the present invention;

[0036] Figure 2 This is the second flowchart illustrating the method for calculating vibration noise of a flow-induced cylindrical shell structure provided by this invention.

[0037] Figure 3 This is a schematic diagram of a flow-induced cylindrical shell, illustrating the method for calculating vibration noise of a flow-induced cylindrical shell structure provided by this invention.

[0038] Figure 4 This is a schematic diagram comparing the mean square vibration velocities in the flow-induced cylindrical shell structure vibration noise calculation method provided by this invention.

[0039] Figure 5 This is a schematic diagram comparing radiated acoustic power in the flow-induced cylindrical shell structure vibration noise calculation method provided by the present invention.

[0040] Figure 6 This is a schematic diagram of the flow-induced cylindrical shell structure vibration noise calculation device provided by the present invention. Detailed Implementation

[0041] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0042] The following is combined with Figure 1 and Figure 2 The present invention describes a method for calculating the vibration noise of a flow-induced cylindrical shell structure, comprising:

[0043] Step 101: Determine the turbulent boundary layer parameters on the surface of the cylindrical shell structure based on the geometric model and flow field information of the cylindrical shell structure. Substitute the turbulent boundary layer parameters into the empirical model of the cross power spectrum of the fluctuating pressure on the wall of the turbulent boundary layer of the flat plate and convolve it with the Dirac comb function to obtain the cross power spectrum function of the fluctuating pressure of the turbulent boundary layer on the cylindrical surface.

[0044] Step 102: Using the uncorrelated wall pressure spiral wave technique and substituting the cross power spectrum function of the turbulent boundary layer pulsating pressure of the cylindrical surface, the equivalent synthetic wall pressure field of the cylindrical surface is obtained.

[0045] Step 103: Divide the structural mesh and acoustic mesh according to the geometric model of the cylindrical shell structure, establish the fluid-structure interaction finite element model of the cylindrical shell structure using the finite element method based on the structural mesh and acoustic mesh, and apply the corresponding boundary conditions;

[0046] Step 104: The equivalent composite wall pressure field of the cylindrical surface is applied to the cylindrical shell surface in the fluid-structure interaction finite element model as a surface excitation for finite element solution, and the vibration and sound radiation of the cylindrical shell structure are obtained as vibration noise results.

[0047] The effectiveness of the proposed method is verified using a cylindrical shell excited by a turbulent boundary layer. The cylindrical shell is adjacent to water and has simply supported boundary conditions at both ends, as illustrated in the diagram below. Figure 3 As shown in Table 1, the geometric parameters and material properties of the cylindrical shell are presented. The mean square vibration velocity and radiated acoustic power of the cylindrical shell under turbulent boundary layer excitation were calculated using the proposed method. The analysis frequency range was from 10 Hz to 600 Hz, with a frequency step size of 2 Hz.

[0048] Table 1 Parameter Table for Cylindrical Shells

[0049] parameter numerical values Radius, R (m) 0.5 Length, L (m) 3.0 Thickness, h (m) 0.01 Young's modulus, E (GPa) 70 <![CDATA[Density, ρ (kg / m 3 )]]> 2700 Poisson's ratio, υ 0.33 Damping loss factor, η 0.005

[0050] Assume that turbulence on the cylindrical shell is fully developed. The turbulent flow direction is along the axis of the cylindrical shell. The length of the cylindrical shell is considered the characteristic length when calculating the Reynolds number. The density and kinematic viscosity of the fluid are both 1000 kg / m³. 3 The turbulent flow velocity is 1.006 × 10⁻⁶ m² / s. The turbulent flow velocity is 5 m / s. The self-power spectral density function of the turbulent fluctuating pressure is derived using the Goody model.

[0051] (1)

[0052] in It is wall shear stress. It is the boundary layer thickness. It is the displacement velocity at the edge of the boundary layer. , It is dynamic viscosity. It is the wall friction speed.

[0053] The calculation results of the proposed method were compared with those of methods in the literature. A comparison of mean square velocity levels was provided. Figure 4 As shown, the comparison of radiated sound power levels is as follows: Figure 5 As shown. The mean square velocity level calculated by this method is in almost perfect agreement with the results obtained by the literature method, and the results for the radiated sound power level also show a high degree of consistency.

[0054] This embodiment transforms the expression of turbulent boundary layer pulsating pressure on the wall of a flat plate into a cross-power spectrum empirical model by substituting the turbulent boundary layer parameters into the Dirac comb function, thereby obtaining the cross-power spectrum function of turbulent boundary layer pulsating pressure on a cylindrical surface. Based on the uncorrelated wall pressure spiral wave technique, this cross-power spectrum function of turbulent boundary layer pulsating pressure on a cylindrical surface is then substituted into the cross-power spectrum function of turbulent boundary layer pulsating pressure on a cylindrical surface to obtain the equivalent synthetic wall pressure field of the cylindrical surface. This transforms the expression of turbulent boundary layer pulsating pressure on the cylindrical shell surface from the original frequency wavenumber spectrum into a deterministic pressure expression. In other words, it transforms the stochastic analysis problem of vibration and noise of a cylindrical shell structure under turbulent boundary layer excitation into a deterministic problem, improving the feasibility and efficiency of solving using finite element software.

[0055] Based on the above embodiments, this embodiment substitutes the cross-power spectrum function of the fluctuating pressure of the cylindrical turbulent boundary layer into the unrelated wall pressure spiral wave to obtain the equivalent synthetic wall pressure field of the cylindrical surface, including:

[0056] By changing the random phase factor of the uncorrelated wall pressure spiral wave, multiple sets of different equivalent composite wall pressure fields are obtained on the cylindrical surface, which serve as the input load for the finite element method.

[0057] Based on the above embodiments, in this embodiment, the equivalent composite wall pressure field of the cylindrical surface is applied to the surface of the cylindrical shell in the fluid-structure interaction finite element model as a surface excitation for finite element solution, to obtain the vibration and acoustic radiation of the cylindrical shell structure, including:

[0058] Each set of equivalent composite wall pressure fields of the cylindrical surface is applied to the surface of the cylindrical shell in the fluid-structure interaction finite element model as a surface excitation for finite element solution, and the vibration and acoustic radiation of the cylindrical shell structure are obtained.

[0059] The average vibration of the multiple sets of vibrations and the average acoustic radiation of the multiple sets of acoustic radiations of the cylindrical shell structure are taken as the final vibration noise result of the cylindrical shell structure excited by the turbulent boundary layer.

[0060] Repeat the loading and calculation process in step 104 for the multiple sets of equivalent composite wall pressure fields obtained in step 102 to obtain multiple sets of vibration and acoustic radiation results of the cylindrical shell.

[0061] The ensemble average of multiple sets of cylindrical shell vibration and acoustic radiation results is taken as the final vibration and noise result of the turbulent boundary layer-excited cylindrical shell structure.

[0062] Based on the above embodiments, in this embodiment, the cross-power spectrum function of the fluctuating pressure of the turbulent boundary layer on the wall of the flat plate is obtained by substituting the turbulent boundary layer parameters into the empirical model of the cross-power spectrum of the fluctuating pressure on the wall of the turbulent boundary layer using the following formula and convolving it with the Dirac comb function:

[0063] (2)

[0064] in, This is the cross-power spectral function of the fluctuating pressure in the turbulent boundary layer of a cylindrical surface. For the empirical model of the cross-power spectrum of fluctuating pressure on the wall of a flat plate turbulent boundary layer, the period of the Dirac comb function is... R is the radius of the cylindrical shell structure, and M represents the comb function. The relative distance between two points in terms of flow direction (axial direction). The spanwise (circumferential) relative distance between two points. It is the angular frequency.

[0065] For a cylindrical shell of radius R excited by a turbulent boundary layer, the flow spacing between observation points increases linearly along the axial direction, while the spanwise spacing increases linearly along the circumferential direction. The periodic variation is periodic. Based on the convolution property of the impulse function, the cross-power spectral density model of the turbulent boundary layer excitation of the flat plate is compared with the periodic variation in the circumferential direction. Convolution with a periodic comb function yields the cross-power spectrum function of the fluctuating pressure in the turbulent boundary layer of a cylindrical surface.

[0066] Based on the above embodiments, this embodiment substitutes the cross-power spectrum function of the fluctuating pressure of the cylindrical turbulent boundary layer into the unrelated wall pressure spiral wave to obtain the equivalent synthetic wall pressure field of the cylindrical surface, including:

[0067] The cross-power spectrum function of the fluctuating pressure in the turbulent boundary layer of the cylindrical surface is subjected to Fourier transform to obtain the frequency wavenumber spectrum function of the fluctuating pressure in the turbulent boundary layer of the cylindrical surface.

[0068] The equivalent composite wall pressure field of the cylindrical surface is determined based on the frequency wavenumber spectrum function of the fluctuating pressure in the turbulent boundary layer of the cylindrical surface.

[0069] Taking a Fourier transform of equation (2), we obtain the pulsating pressure wavenumber spectrum function of the cylinder, which is expressed by the pulsating pressure wavenumber spectrum of the flat plate:

[0070] (3)

[0071] Spatial frequency spectrum in physical space yes Wavenumber frequency spectrum in wavenumber space The Fourier transform of can be expressed using the axial Fourier transform and the circumferential Fourier series:

[0072] (4)

[0073] Discretizing it in the wavenumber domain yields:

[0074] (5)

[0075] Based on the above embodiments, this embodiment determines the equivalent composite wall pressure field of the cylindrical surface according to the frequency wavenumber spectrum function of the fluctuating pressure in the turbulent boundary layer of the cylindrical surface using the following formula:

[0076]

[0077] in, For the s-th group of equivalent composite wall pressure fields, Let R be the coordinates of the i-th point on the cylindrical surface, and R be the radius of the cylindrical shell structure. The wave number in the s-th group is The phase of the spiral wave is in [0, A random phase factor distributed within the range. The frequency wavenumber spectrum function of the fluctuating pressure in the turbulent boundary layer of the cylindrical surface is given. It is the boundary layer thickness. Where P is the angular frequency, Q is the number of wavenumber samples in the flow direction (axial direction), and j is the imaginary unit. denoted as axial wavenumber and n as circumferential wavenumber.

[0078] Suppose a cylindrical shell is subjected to a set of uncorrelated wall pressure helical wave loads. The form of the (p, q)th helical wave set can be assumed to be:

[0079] (6)

[0080] in For the wave number is The random variable corresponding to the amplitude of the spiral wave. Then the cross-power spectral density function of the pressure between two points on the cylindrical shell is:

[0081] (7)

[0082] in, This is the self-power spectral density function of the wall pressure helical wave amplitude in the frequency domain.

[0083] When multiple sets of wall pressure spiral waves of the form of formula (6) are superimposed, a certain point on the cylindrical shell... Total pressure for:

[0084] (8)

[0085] Due to the uncorrelated nature of the helical waves, the cross-power spectral density function of the total pressure between two points on the surface of the cylindrical shell can be obtained through Fourier transform as follows:

[0086] (9)

[0087] Comparing equations (5) and (9), it can be found that when the self-power spectral density function of the wall pressure helical wave satisfies equation (10), the turbulent pulsating pressure excitation can be equivalently represented by multiple sets of unrelated wall pressure helical waves:

[0088] (10)

[0089] Thus, under the superposition of multiple sets of unrelated wall pressure spiral waves, a certain point on the surface of the cylindrical shell... The total combined pressure can be represented by the turbulent pulsating pressure frequency wavenumber spectrum of the cylindrical shell:

[0090] (11)

[0091] Here, the superscript 's' indicates the composite wall pressure field during the 's'th repeated calculation.

[0092] Formula (11) transforms the expression of turbulent boundary layer fluctuation pressure on the surface of a cylindrical shell from the original frequency wavenumber spectrum into a deterministic pressure expression, which is to say, transforms a stochastic analysis problem into a deterministic problem.

[0093] Based on the above embodiments, the turbulent boundary layer parameters in this embodiment include migration velocity, empirical constants for flow direction and span, boundary layer thickness, and Reynolds number.

[0094] The following describes the flow-induced cylindrical shell structure vibration and noise calculation device provided by the present invention. The flow-induced cylindrical shell structure vibration and noise calculation device described below and the flow-induced cylindrical shell structure vibration and noise calculation method described above can be referred to in correspondence.

[0095] like Figure 6 As shown, the device includes a convolution module 601, an acquisition module 602, a construction module 603, and a solution module 604, wherein:

[0096] The convolution module 601 is used to determine the turbulent boundary layer parameters of the cylindrical shell structure surface based on the geometric model and flow field information of the cylindrical shell structure, and then to convolve the turbulent boundary layer parameters into the empirical model of the cross power spectrum of the fluctuating pressure of the turbulent boundary layer wall of the flat plate with the Dirac comb function to obtain the cross power spectrum function of the fluctuating pressure of the turbulent boundary layer of the cylindrical surface.

[0097] The acquisition module 602 is used to obtain the equivalent synthetic wall pressure field of the cylindrical surface by using the uncorrelated wall pressure spiral wave technology and substituting the cross power spectrum function of the turbulent boundary layer pulsating pressure of the cylindrical surface.

[0098] The construction module 603 is used to divide the structural mesh and acoustic mesh according to the geometric model of the cylindrical shell structure, establish the fluid-structure interaction finite element model of the cylindrical shell structure using the finite element method according to the structural mesh and acoustic mesh, and apply the corresponding boundary conditions;

[0099] The solver module 604 is used to apply the equivalent composite wall pressure field of the cylindrical surface to the cylindrical shell surface in the fluid-structure interaction finite element model as a surface excitation for finite element solution, and obtain the vibration and sound radiation of the cylindrical shell structure as vibration noise results.

[0100] This embodiment transforms the expression of turbulent boundary layer pulsating pressure on the wall of a flat plate into a cross-power spectrum empirical model by substituting the turbulent boundary layer parameters into the Dirac comb function, thereby obtaining the cross-power spectrum function of turbulent boundary layer pulsating pressure on a cylindrical surface. Based on the uncorrelated wall pressure spiral wave technique, this cross-power spectrum function of turbulent boundary layer pulsating pressure on a cylindrical surface is then substituted into the cross-power spectrum function of turbulent boundary layer pulsating pressure on a cylindrical surface to obtain the equivalent synthetic wall pressure field of the cylindrical surface. This transforms the expression of turbulent boundary layer pulsating pressure on the cylindrical shell surface from the original frequency wavenumber spectrum into a deterministic pressure expression. In other words, it transforms the stochastic analysis problem of vibration and noise of a cylindrical shell structure under turbulent boundary layer excitation into a deterministic problem, improving the feasibility and efficiency of solving using finite element software.

[0101] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for calculating vibration noise of a flow-induced cylindrical shell structure, characterized in that, include: Based on the geometric model and flow field information of the cylindrical shell structure, the turbulent boundary layer parameters on the surface of the cylindrical shell structure are determined. The turbulent boundary layer parameters are then substituted into the empirical model of the cross power spectrum of the fluctuating pressure of the turbulent boundary layer wall of the flat plate and convolved with the Dirac comb function to obtain the cross power spectrum function of the fluctuating pressure of the turbulent boundary layer of the cylindrical surface. By employing the uncorrelated wall pressure spiral wave technique and substituting the cross power spectrum function of the fluctuating pressure of the turbulent boundary layer on the cylindrical surface, the equivalent synthetic wall pressure field of the cylindrical surface is obtained. Based on the geometric model of the cylindrical shell structure, structural mesh and acoustic mesh are divided. Based on the structural mesh and acoustic mesh, a fluid-structure interaction finite element model of the cylindrical shell structure is established using the finite element method, and corresponding boundary conditions are applied. The equivalent composite wall pressure field of the cylindrical surface is applied to the surface of the cylindrical shell in the fluid-structure interaction finite element model as a surface excitation for finite element solution, and the vibration and sound radiation of the cylindrical shell structure are obtained as vibration noise results.

2. The method for calculating vibration noise of a flow-induced cylindrical shell structure according to claim 1, characterized in that, Using the uncorrelated wall pressure spiral wave technique and substituting the cross-power spectrum function of the fluctuating pressure in the turbulent boundary layer of the cylindrical surface, the equivalent synthetic wall pressure field of the cylindrical surface is obtained, including: By changing the random phase factor of the uncorrelated wall pressure spiral wave, multiple sets of different equivalent composite wall pressure fields are obtained on the cylindrical surface, which serve as the input load for the finite element method.

3. The method for calculating vibration noise of a flow-induced cylindrical shell structure according to claim 2, characterized in that, The equivalent composite wall pressure field of the cylindrical surface is applied to the surface of the cylindrical shell in the fluid-structure interaction finite element model as a surface excitation for finite element solution, resulting in the vibration and acoustic radiation of the cylindrical shell structure, including: Each set of equivalent composite wall pressure fields of the cylindrical surface is applied to the surface of the cylindrical shell in the fluid-structure interaction finite element model as a surface excitation for finite element solution, and the vibration and acoustic radiation of the cylindrical shell structure are obtained. The average vibration of the multiple sets of vibrations and the average acoustic radiation of the multiple sets of acoustic radiations of the cylindrical shell structure are taken as the final vibration noise result of the cylindrical shell structure excited by the turbulent boundary layer.

4. The method for calculating vibration noise of a flow-induced cylindrical shell structure according to claim 1, characterized in that, The cross-power spectrum function of the fluctuating pressure in the turbulent boundary layer on a cylindrical surface is obtained by substituting the turbulent boundary layer parameters into the empirical model of the cross-power spectrum of the fluctuating pressure on the wall of a flat plate turbulent boundary layer and convolving it with the Dirac comb function: ; in, This is the cross-power spectral function of the fluctuating pressure in the turbulent boundary layer of a cylindrical surface. For the empirical model of the cross-power spectrum of fluctuating pressure on the wall of a flat plate turbulent boundary layer, the period of the Dirac comb function is... R is the radius of the cylindrical shell structure, and M represents the comb function. The relative distance between two points in terms of flow direction. The spanwise relative distance between two points It is the angular frequency.

5. The method for calculating vibration noise of a flow-induced cylindrical shell structure according to claim 2, characterized in that, Substituting the cross-power spectrum function of the fluctuating pressure of the cylindrical turbulent boundary layer into the uncorrelated wall pressure helical wave yields the equivalent synthetic wall pressure field of the cylindrical surface, including: The cross-power spectrum function of the fluctuating pressure in the turbulent boundary layer of the cylindrical surface is subjected to Fourier transform to obtain the frequency wavenumber spectrum function of the fluctuating pressure in the turbulent boundary layer of the cylindrical surface. The equivalent composite wall pressure field of the cylindrical surface is determined based on the frequency wavenumber spectrum function of the fluctuating pressure in the turbulent boundary layer of the cylindrical surface.

6. The method for calculating vibration noise of a flow-induced cylindrical shell structure according to claim 5, characterized in that, The equivalent composite wall pressure field of the cylindrical surface is determined using the following formula based on the frequency wavenumber spectrum function of the fluctuating pressure in the turbulent boundary layer of the cylindrical surface: ; in, For the s-th group of equivalent composite wall pressure fields, Let R be the coordinates of the i-th point on the cylindrical surface, and R be the radius of the cylindrical shell structure. The wave number in the s-th group is The phase of the spiral wave is in [0, A random phase factor distributed within the range. The frequency wavenumber spectrum function of the fluctuating pressure in the turbulent boundary layer of the cylindrical surface is given. It is the boundary layer thickness. Where is the angular frequency, P is the number of streamwise wavenumber samples, Q is the number of spanwise wavenumber samples, and j is the imaginary unit. denoted as axial wavenumber and n as circumferential wavenumber.

7. The method for calculating vibration noise of a flow-induced cylindrical shell structure according to any one of claims 1-6, characterized in that, The turbulent boundary layer parameters include migration velocity, empirical constants for flow direction and span, boundary layer thickness, and Reynolds number.

8. A device for calculating the vibration noise of a flow-induced cylindrical shell structure, characterized in that, include: The convolution module is used to determine the turbulent boundary layer parameters of the cylindrical shell structure surface based on the geometric model and flow field information of the cylindrical shell structure, and then to convolve the turbulent boundary layer parameters into the empirical model of the cross power spectrum of the fluctuating pressure of the turbulent boundary layer wall of the flat plate with the Dirac comb function to obtain the cross power spectrum function of the fluctuating pressure of the turbulent boundary layer of the cylindrical surface. The acquisition module is used to obtain the equivalent synthetic wall pressure field of the cylindrical surface by using the uncorrelated wall pressure spiral wave technology and substituting the cross power spectrum function of the turbulent boundary layer pulsating pressure of the cylindrical surface. The module is used to divide the structural mesh and acoustic mesh according to the geometric model of the cylindrical shell structure, establish the fluid-structure interaction finite element model of the cylindrical shell structure using the finite element method based on the structural mesh and acoustic mesh, and apply the corresponding boundary conditions. The solver module is used to apply the equivalent composite wall pressure field of the cylindrical surface to the cylindrical shell surface in the fluid-structure interaction finite element model as a surface excitation for finite element solution, and obtain the vibration and sound radiation of the cylindrical shell structure as vibration noise results.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the program, it implements the method for calculating the vibration noise of a flow-induced cylindrical shell structure as described in any one of claims 1 to 7.

10. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the method for calculating the vibration noise of a flow-induced cylindrical shell structure as described in any one of claims 1 to 7.

Images