A method for testing and visualizing analysis of sound wave generation and propagation process

Abstract

The application provides a method for testing and visualizing analysis of sound wave generation and propagation process, comprising the following steps: S1, installing acceleration sensors at different positions of a mechanical structure generating intense vibration, measuring vibration state of the mechanical structure, and characterizing vibration features of the mechanical structure based on vibration acceleration data of the acceleration sensors at different positions and interpolation; S2, calculating normal sound wave speed variables of particles at the surface of the mechanical structure in air or water medium based on normal acceleration fluctuation variables of the vibration features of the mechanical structure; S3, using linear Euler equation to describe evolution states of energy dissipation, sound scattering and sound reflection of the normal sound wave speed variables in the propagation process; and S4, performing data visualizing analysis based on the evolution states. The application improves the design capability of noise suppression of mechanical equipment, and enables intuitive observation of the generation and propagation states of sound waves by using visualizing analysis.

Description

Technical Field

[0001] This invention relates to the technical field of acoustic wave testing and visualization analysis, specifically to a method for testing and visualizing the acoustic wave generation and propagation process. Background Technology

[0002] Sound waves propagate rapidly in all directions through various media, and their amplitude significantly affects people's quality of life. To monitor the magnitude of sound waves generated during the operation of mechanical equipment, sensors such as microphones and hydrophones are commonly used for measurement. However, existing experimental measurement sensors can only capture the amplitude of sound waves at a specific spatial location, failing to simultaneously characterize the spatiotemporal evolution of sound wave generation and propagation, thus increasing the difficulty of testing and analyzing the vibration sound waves of mechanical equipment. Furthermore, traditional methods for testing and visualizing the sound wave generation and propagation process employ acoustic cameras. These devices can trace the sound source distribution of mechanical equipment based on the magnitude and phase of sound waves at array locations within the sound field. However, this method ignores the fact that the generation and propagation path of sound waves is a reverse tracing method, making it highly susceptible to interference from multiple sound sources within the mechanical equipment.

[0003] Therefore, both acoustic wave testing and visualization analysis currently suffer from significant interference issues in terms of accuracy. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a method for testing and visualizing the generation and propagation process of sound waves, thereby solving the technical problem that the accuracy of current sound wave testing and visualization analysis suffers from significant interference.

[0005] This invention provides a method for testing and visualizing the generation and propagation process of sound waves, comprising:

[0006] S1. Accelerometers are installed at different locations where the mechanical structure experiences severe vibrations. Based on the vibration acceleration data from the accelerometers at different locations, the vibration characteristics of the mechanical structure are characterized by interpolation.

[0007] S2. Based on the normal acceleration fluctuation variable of the vibration characteristics of the mechanical structure, calculate the normal sound wave velocity variable of the particles at the air or water medium on the surface of the mechanical structure.

[0008] S3. Using the linear Euler equation, describe the evolution of energy dissipation, sound scattering, and sound reflection of the normal sound wave velocity variable during propagation.

[0009] S4. Based on the evolutionary state, perform data visualization analysis.

[0010] Optionally, the installation of acceleration sensors at different locations where severe vibrations occur in the mechanical structure, and the interpolation of vibration acceleration data from the acceleration sensors at different locations to characterize the vibration features of the mechanical structure, includes:

[0011] The interpolation formula is expressed as follows:

[0012] a w (x,t n ) = A w (s,t n )δ(xX(s,t n ))

[0013]

[0014]

[0015] Among them, a w (x,t n Let t be any position x in three-dimensional space of the accelerometer. n The normal acceleration matrix at time A w (s,t n ) represents the position of the accelerometer at point X(s). n The normal acceleration matrix at time t, where h is the spacing between the uniformly arranged accelerometer sensors, and r = xX(s,t) in the x-axis. n ) / h, in the y-dimensional r=yY(s,t n ) / h, in the z-axis r=zZ(s,t) n ) / h.

[0016] Optionally, the calculation of the normal sound wave velocity variable of particles at the surface of the mechanical structure in air or water medium based on the normal acceleration fluctuation variable of the vibration characteristics of the mechanical structure includes:

[0017] Based on the normal acceleration matrix A w (s,t n Calculate the velocity fluctuation variable, and the formula for calculating the velocity fluctuation variable is:

[0018] Δu w (x,t n ) = a w (x,t n )Δt

[0019] Where: Δt is the sampling time interval of the accelerometer on the housing of the mechanical structure, and the velocity fluctuation variable Δu w (x,t n ) is the normal acoustic wave velocity variable of particles at the air or water medium on the surface of a mechanical structure.

[0020] Optionally, the linear Euler equation is used to describe the evolution of energy dissipation, sound scattering, and sound reflection of the normal sound wave velocity variable during propagation, including:

[0021] The formula for calculating the evolutionary state is as follows:

[0022]

[0023]

[0024]

[0025] Where S′ is the magnitude of the sound source term, expressed as Δu w (t) is decomposed into the sound wave velocity u a The components u in the x, y, z directions a ,v a ,w a , ρ is the average fluid density in a non-uniform flow field. a (x,t), u a (x,t) and p a (x,t) represents the instantaneous fluid wave density, velocity, and pressure variables caused by the sound wave, c0 represents the wave propagation speed of the sound wave in the air or water medium, the subscript f represents the fluid field variable, the subscript a represents the sound field wave variable, and the subscript s′ represents the sound source term.

[0026] Optionally, the data visualization analysis based on the evolutionary state includes:

[0027] Using sound pressure cloud maps, the generation and propagation process of sound waves caused by mechanical structure vibration is displayed in real time, realizing the visualization analysis of sound wave generation and propagation, and performing Fourier transform analysis on the spectral characteristics of sound waves at any position in three-dimensional space.

[0028] Optionally, the method of using sound pressure cloud maps to display the generation and propagation process of sound waves caused by mechanical structure vibration in real time, realizing a visual analysis of sound wave generation and propagation, including:

[0029] Using the pcolor function in MATLAB, the sound pressure at any location in three-dimensional space is filled with color to form a three-dimensional sound pressure cloud map, which is useful for observing the generation and propagation of sound waves caused by the vibration of a mechanical structure at a certain moment.

[0030] Optionally, the step of performing Fourier transform analysis on the spectral characteristics of sound waves at arbitrary locations in three-dimensional space includes:

[0031] Capture the time-varying signal of sound pressure at any location in three-dimensional space. aThe Fourier transform of (x,t) is used to obtain its spectral characteristics. The Fourier transform calculation formula is as follows:

[0032]

[0033] Where ω is the frequency magnitude, and i is the imaginary unit in the complex number.

[0034] Compared with the prior art, the present invention has the following beneficial effects:

[0035] By arranging certain acceleration sensors on the mechanical structure and microphones or hydrophones in the air and water media, and using a method that couples test data with numerical calculation results, the spatiotemporal synchronous monitoring of the sound wave generation and propagation process can be achieved. This is beneficial for analyzing the generation location and propagation path of sound waves, thereby improving the design capability of noise suppression for mechanical equipment. Furthermore, by using visualization analysis, the generation and propagation status of sound waves can be observed intuitively. Attached Figure Description

[0036] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0037] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0038] Figure 1 This is a schematic diagram of the method flow of the present invention;

[0039] Figure 2 This is a schematic diagram of the arrangement of the acceleration sensor and the striking position of the force hammer in one embodiment of the present invention;

[0040] Figure 3 This is a schematic diagram of the microphone sensor arrangement in one embodiment of the present invention;

[0041] Figure 4 This is a photograph of an experimental setup of a hammer striking a casing to produce acoustic radiation, according to one embodiment of the present invention.

[0042] Figure 5 This is a sound pressure cloud image of the instantaneous sound pressure level when the hammer strikes directly above the target in one embodiment of the present invention;

[0043] Figure 6 This is a schematic diagram showing the sound pressure level spectrum comparison results when the shell is struck directly above by a hammer in one embodiment of the present invention. Detailed Implementation

[0044] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application. Functional units with the same reference numerals in the examples of this invention have the same and similar structures and functions.

[0045] The terms involved in this invention are explained as follows:

[0046] Sound waves are mechanical waves that propagate in a wave-like manner, generated by the vibration of a sound source. The space in which sound waves propagate is called the sound field. The propagation process can be understood as a small disturbance in the medium deviating from its equilibrium state, involving only energy transfer without mass transfer. If the disturbance is small, the sound wave propagation satisfies the classical wave equation and is a linear wave. If the disturbance is large, it does not satisfy the linear sound wave equation, and wave dispersion and the generation of shock waves will occur.

[0047] A microphone sensor is a sensor that detects sound waves in the air through electromagnetic induction and changes. It can detect the magnitude and frequency of sound waves in the air, obtain the sound wave signal changing over time at the microphone location through a data acquisition device, and display the fluctuation state of the sound waves over time through an oscilloscope.

[0048] A hydrophone is a transducer that converts sound signals in a water medium into electrical signals. It can detect the magnitude and frequency of sound waves in a water medium. By using a data acquisition unit and an oscilloscope, the sound wave signal at the location of the hydrophone and its fluctuation state over time can be obtained.

[0049] Noise suppression refers to taking measures to suppress the generation of sound waves, block or weaken their propagation, and optimize the generation and propagation levels of sound waves in mechanical equipment during the sound wave generation and propagation process. Therefore, improving noise suppression capabilities requires enhancing the testing and visualization analysis techniques for the sound wave generation and propagation process.

[0050] An acoustic camera is a device that works by measuring the phase difference of sound waves reaching each microphone within a certain space, determining the location of the sound source based on the phased array principle, measuring the amplitude of the sound source, and displaying the distribution of the sound source in space as an image, i.e., obtaining a spatial sound field distribution cloud map - an acoustic image, where the color and brightness of the image represent the intensity.

[0051] See Figure 1 This invention provides a method for testing and visualizing the generation and propagation process of sound waves, comprising:

[0052] S1. Accelerometers are installed at different locations where the mechanical structure experiences severe vibrations. Based on the vibration acceleration data from the accelerometers at different locations, the vibration characteristics of the mechanical structure are characterized by interpolation.

[0053] S2. Based on the normal acceleration fluctuation variable of the vibration characteristics of the mechanical structure, calculate the normal sound wave velocity variable of the particles at the air or water medium on the surface of the mechanical structure.

[0054] S3. Using the linear Euler equation, describe the evolution of energy dissipation, sound scattering, and sound reflection of the normal sound wave velocity variable during propagation.

[0055] S4. Based on the evolutionary state, perform data visualization analysis.

[0056] The specific implementation process of this invention is as follows:

[0057] In this embodiment, step S1 involves installing accelerometers at different locations where the mechanical structure experiences severe vibrations. Based on the vibration acceleration data from these sensors at different locations, the vibration characteristics of the mechanical structure are characterized through interpolation. The purpose of step S1 is to collect vibration source data. For the vibration state of the mechanical structure during operation, normal accelerometers are uniformly arranged at the locations of the most intense vibrations to measure the vibration state. Based on the three-dimensional spatial positions of different sensors, a normal acceleration interpolation method is constructed for any three-dimensional spatial position to obtain the magnitude of the normal acceleration across the entire surface of the mechanical structure. The interpolation calculation formula is as follows:

[0058] a w (x,t n ) = A w (s,t n )δ(xX(s,t n ))

[0059]

[0060]

[0061] Among them, a w (x,t n ) represents any position x in three-dimensional space, where t is t. n The normal acceleration matrix at time A w (s,t n ) represents the position of the accelerometer at point X(s). n The normal acceleration matrix at time t, where h is the spacing between the uniformly arranged accelerometer sensors, and r = xX(s,t) in the x-axis. n ) / h, in the y-dimensional r=yY(s,t n ) / h, in the z-axis r=zZ(s,t)n ) / h.

[0062] S2. Based on the normal acceleration fluctuation variable of the vibration characteristics of the mechanical structure, calculate the normal sound wave velocity variable of the particles at the air or water medium on the surface of the mechanical structure.

[0063] The purpose of step S2 is to transform the aforementioned vibration source into a sound source, based on the normal acceleration matrix A. w (s,t n Calculate the velocity fluctuation variable, and the formula for calculating the velocity fluctuation variable is:

[0064] Δu w (x,t n ) = a w (x,t n )Δt

[0065] Where: Δt is the sampling time interval of the accelerometer on the housing of the mechanical structure, and the velocity fluctuation variable Δu w (x,t n As a variable representing the normal acoustic wave velocity of particles in the air or water medium on the surface of a mechanical structure, it serves as a sound source to simulate the sound radiation of mechanical structure vibration.

[0066] S3. Using the linear Euler equation, describe the evolution of energy dissipation, sound scattering, and sound reflection of the normal sound wave velocity variable during propagation.

[0067] The purpose of step S2 is to consider that sound waves propagate as linear small-perturbation waves, and to use the linear Euler equation to describe the energy dissipation, sound scattering, and sound reflection states during the sound wave propagation process. The calculation formula for the evolution state is as follows:

[0068]

[0069]

[0070]

[0071] Where S′ is the magnitude of the sound source term, this patent uses Δu w (t) is decomposed into the sound wave velocity u a The components u in the x, y, z directions a ,v a ,w a , ρ is the average fluid density in a non-uniform flow field. a (x,t), u a (x,t) and p a(x,t) represents the instantaneous fluid wave density, velocity, and pressure variables caused by the sound wave, c0 represents the wave propagation speed of the sound wave in the air or water medium, the subscript f represents the fluid field variable, the subscript a represents the sound field wave variable, and the subscript s′ represents the sound source term.

[0072] S4. Based on the evolutionary state, perform data visualization analysis.

[0073] The purpose of step S4 is to achieve data visualization analysis. Based on the pcolor function in MATLAB, color is filled to the sound pressure at any location in three-dimensional space to form a three-dimensional sound pressure cloud map, so as to facilitate the observation of the generation and propagation state of sound waves caused by the vibration of mechanical structure at a certain moment; and to capture the time-varying signal p of the sound pressure at any location in three-dimensional space. a The Fourier transform of (x,t) is used to obtain its spectral characteristics. The Fourier transform calculation formula is as follows:

[0074]

[0075] Where ω is the frequency magnitude, and i is the imaginary unit in the complex number.

[0076] This invention achieves spatiotemporal synchronous monitoring of the sound wave generation and propagation process by arranging certain acceleration sensors on the mechanical structure and microphones or hydrophones in the air and water media, and by coupling test data with numerical calculation results. This is beneficial for analyzing the generation location and propagation path of sound waves, and solves the problem of mutual interference between multiple sound sources in mechanical equipment, thereby improving the design capability of noise suppression of mechanical equipment. Furthermore, the use of visualization analysis allows for intuitive observation of the generation and propagation state of sound waves.

[0077] In another embodiment, experiments were conducted to illustrate the invention:

[0078] The experiment was conducted on a cylindrical shell model test bench, and included equipment such as a cylindrical shell model, a force hammer, an accelerometer, a microphone sensor, and a Yiheng data acquisition and transmission instrument. The arrangement of the accelerometer and the impact position of the force hammer are as follows: Figure 2 As shown, four accelerometers are evenly arranged on the surface of the cylindrical shell, and three hammer impact positions are set: diagonally above, directly above, and directly to the side. Furthermore, when the hammer impact position coincides with an accelerometer sensor position, the accelerometer sensor corresponding to that position is placed on the inner wall of the cylindrical shell.

[0079] The arrangement of the microphone sensors is as follows Figure 3As shown, the height of the microphone sensor is consistent with the center height of the cylindrical shell. In this experiment, the research object is the radiated sound waves of the vibrating shell. Since the surface of the cylindrical shell is the sound source region, and the radiated sound waves propagate in a static fluid field, the small area on the surface of the cylindrical shell (less than 0.1m) is its sound source region. However, this laboratory is not an anechoic chamber; it contains multiple large experimental platforms (obstacles), and the sound waves are reflected or scattered by the floor, ceiling, and obstacles during propagation. Therefore, the area within the dashed box in the figure represents the sound source region. The distance between the microphone sensor and the surface of the cylindrical shell is set to 0.5m to observe the sound pressure level of the microphone sensor within the sound source region.

[0080] During the experiment, a hammer was used to strike the shell, an accelerometer was used to measure the acceleration vibration signal on the shell surface, and a microphone sound pressure sensor was used to measure the sound pressure level in the sound source area. The experimental setup and testing process are as follows: Figure 4 As shown, the hammer impact point, accelerometer, and microphone sensor are all positioned within the same two-dimensional plane perpendicular to the cylindrical surface. This allows for the acquisition of relevant experimental data within the two-dimensional plane of the cylindrical shell, reducing the influence of radiated sound waves from other cross-sections of the three-dimensional cylindrical shell. Furthermore, the cylindrical shell is placed on cork using four brackets, with no fixed connection between the brackets and the shell. This ensures free vibration of the cylindrical shell and minimizes interference from the support boundary conditions.

[0081] In this experiment, the sampling frequency was Fs = 6000Hz, and the number of sampling points per frame was 8192. During the simulation, the cylindrical shell had a diameter of D = 1.0m and a thickness of b = 0.008m, and the shell material parameter was ρ. s =7850kg / m 3 Young's modulus E = 2.1 × 10 11 Pa, Poisson's ratio is μ = 0.3. Furthermore, the simulated fluid medium is air, with a density of ρ. f =1.234kg / m 3 The speed of sound is c0 = 340.75 m / s, and the viscosity coefficient is μ = 1.79 × 10⁻⁶. -5 Pa·s. The visualization results obtained through the calculation method described in this patent are as follows: Figure 5 As shown, the generation and propagation process of sound waves can be displayed in real time, and the sound pressure level can be compared on the spectrum to obtain the results as shown. Figure 6 As shown, this effectively verifies the accuracy of this patent.

[0082] As can be seen, this invention effectively solves the problems of sound wave generation from mechanical structure vibration, sound wave energy dissipation, sound wave reflection and scattering, and realizes the testing and visualization analysis of the entire process of sound wave generation and propagation.

[0083] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0084] The above description is merely a specific embodiment of the present invention, enabling those skilled in the art to understand or implement the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A method for testing and visualizing the generation and propagation process of sound waves, characterized in that, include: S1. Accelerometers are installed at different locations where the mechanical structure experiences severe vibrations. Based on the vibration acceleration data from the accelerometers at different locations, the vibration characteristics of the mechanical structure are characterized by interpolation. The interpolation formula is expressed as follows: ， ， in, For any position in three-dimensional space of the accelerometer Place The normal acceleration matrix at time t. For the position of the accelerometer Place The normal acceleration matrix at time t. The spacing between uniformly arranged accelerometer sensors is... Dimensions ,exist Dimensions ,exist Dimensions ; S2. Based on the normal acceleration fluctuation variable of the vibration characteristics of the mechanical structure, calculate the normal sound wave velocity variable of the particles at the air or water medium on the surface of the mechanical structure. S3. Using the linear Euler equation, describe the evolution of energy dissipation, sound scattering, and sound reflection of the normal sound wave velocity variable during propagation. S4. Based on the evolutionary state, perform data visualization analysis.

2. The method for testing and visualizing the sound wave generation and propagation process as described in claim 1, characterized in that, The normal acceleration fluctuation variable based on the vibration characteristics of the mechanical structure is used to calculate the normal sound wave velocity variable of particles at the surface of the mechanical structure in air or water, including: Based on the normal acceleration matrix The velocity fluctuation variable is calculated using the following formula: ， in: The sampling time interval of the accelerometer on the housing of the mechanical structure is used to represent the velocity fluctuation variable. As a variable representing the normal acoustic wave velocity of particles at the surface of a mechanical structure in air or water medium.

3. The method for testing and visualizing the sound wave generation and propagation process as described in claim 2, characterized in that, The linear Euler equations are used to describe the evolution of energy dissipation, sound scattering, and sound reflection of the normal sound wave velocity variable during propagation, including: The formula for calculating the evolutionary state is as follows: ， ， ， in, For the size of the sound source term, use Decomposed into sound wave velocity exist Components in direction , The average fluid density in a non-uniform flow field , and The instantaneous fluid wave density, velocity, and pressure variables caused by sound waves. The speed of sound wave propagation in air or water medium, subscript Represents fluid field variables, subscript Indicates the sound field fluctuation variable, subscript This is the sound source term.

4. The method for testing and visualizing the sound wave generation and propagation process as described in claim 3, characterized in that, The data visualization analysis based on the evolutionary state includes: Using sound pressure cloud maps, the generation and propagation process of sound waves caused by mechanical structure vibration is displayed in real time, realizing the visualization analysis of sound wave generation and propagation, and performing Fourier transform analysis on the spectral characteristics of sound waves at any position in three-dimensional space.

5. The method for testing and visualizing the sound wave generation and propagation process as described in claim 4, characterized in that, The method of using sound pressure cloud maps to display the generation and propagation process of sound waves caused by mechanical structure vibration in real time, realizing a visual analysis of sound wave generation and propagation, including: Using the pcolor function in MATLAB, the sound pressure at any location in three-dimensional space is filled with color to form a three-dimensional sound pressure cloud map, which is useful for observing the generation and propagation of sound waves caused by the vibration of a mechanical structure at a certain moment.

6. The method for testing and visualizing the sound wave generation and propagation process as described in claim 4, characterized in that, The method involves performing Fourier transform analysis on sound waves at arbitrary locations in three-dimensional space to determine their spectral characteristics, including: Capture the time-varying signal of sound pressure at any location in three-dimensional space The Fourier transform of the sample is performed to obtain its spectral characteristics. The Fourier transform calculation formula is as follows: ， in, For frequency magnitude, The imaginary part of the unit in a complex number.

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