Aerodynamic noise prediction method and device and electronic equipment

Abstract

The invention discloses an aerodynamic noise prediction method and device and electronic equipment, and belongs to the technical field of acoustics. Comprising the following steps: constructing a sound pressure convection equivalent source model between frequency domain disturbance pressure and convection equivalent source intensity and constructing an acoustic velocity convection equivalent source model between frequency domain disturbance velocity and convection equivalent source intensity according to a first grid node position in a non-closed permeable surface and a convection equivalent source position and angular frequency in a closed equivalent source surface; and determining the convection equivalent source intensity according to the two convection equivalent source models, and further determining the sound pressure and the acoustic velocity of the far-field observation point by combining the position of the far-field observation point and the position of the convection equivalent source. According to the method, the convection effect of a moving medium is considered, far-field noise propagation is predicted by constructing a convection equivalent source model according to a non-closed permeable surface transient flow field without turbulence pulsation components, the false sound radiation phenomenon of a permeable surface is effectively avoided, and false-sound-pollution-free prediction of sound pressure and acoustic speed in the moving medium can be achieved at the same time.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of acoustics, in particular to an aerodynamic noise prediction method and device and electronic equipment. BACKGROUND

[0002] Accurate prediction of far-field aerodynamic sound field is crucial for noise mechanism analysis and low-noise aerodynamic design, and has become a core basic problem in aeroacoustics. A complete aerodynamic sound field includes sound pressure and acoustic velocity (vibration velocity of medium particles caused by sound wave disturbance). The prediction results of far-field sound field combined with sound pressure and acoustic velocity can significantly improve the resolution of numerical identification of aerodynamic sound sources. The far-field aerodynamic sound field is predicted by using the acoustic analogy method, that is, on the basis of fine numerical simulation of the near-field disturbance flow field, the propagation of sound pressure and acoustic velocity is extrapolated by using the acoustic analogy integral equation. In practical applications, the acoustic analogy method often uses a non-physical closed permeable surface as the integral surface. For problems such as flow around and jet, in order to ensure the numerical accuracy of the disturbance flow field of the permeable surface, the selected permeable surface often passes through a certain nonlinear flow region. The disturbance flow field in the nonlinear region contains both acoustic disturbance and turbulent fluctuations, and when the non-acoustic component of the turbulent fluctuations passes through the permeable surface, it will induce false sound radiation, resulting in errors in the prediction results of the sound field. Accurate prediction of far-field aerodynamic sound field requires suppression of false sound pollution of the permeable surface, but there is currently no high-precision false sound suppression technology.

[0003] In the field of aeroacoustics, the existing technology uses three types of methods to suppress false sound pollution on the basis of the acoustic analogy method, but the effect is very limited and cannot effectively avoid the false sound radiation phenomenon of the acoustic velocity at the permeable surface. In the traditional field of acoustics, the existing sound field reconstruction method requires the sound propagation medium to be in a stationary state, but for acoustic problems such as flow around and mixed jet, aerodynamic noise propagates in a moving medium, so the influence of the flow effect of the moving medium on the far-field sound field must be considered. Therefore, the existing sound field reconstruction method based on equivalent sources cannot be applied to the suppression of false sound radiation of the permeable surface. SUMMARY

[0004] To solve the problems existing in the prior art, the present application provides an aerodynamic noise prediction method, device and electronic equipment, which predicts far-field sound pressure and acoustic velocity by constructing a convection equivalent source model based on non-closed permeable surface pressure and velocity data without turbulent fluctuation components. Compared with the acoustic analogy method based on closed permeable surface data, the false sound radiation phenomenon of the permeable surface can be effectively avoided, and aerodynamic sound field prediction without false sound pollution can be realized. Compared with the sound field reconstruction method based on equivalent sources, the influence of the flow effect of the moving medium on sound propagation is considered, and the method is suitable for aerodynamic sound field prediction in a moving medium.

[0005] In a first aspect, the present application provides an aerodynamic noise prediction method, comprising: dividing a non-enclosed permeable surface to obtain M first grid nodes, and discretizing the closed equivalent source surface corresponding to the inside of the non-enclosed permeable surface to obtain N second grid nodes, each second grid node is configured with a convection equivalent source, and M and N are integers greater than 1; wherein, the first The first grid node position is , , No. The convection equivalent source position of the second grid node configuration is , ; According to the first grid node position , convection equivalent source position and angular frequency , combined with the first function formula, determine the first convection transfer function ; and according to the first convection transfer function , construct the frequency domain disturbance pressure of the non-closed permeable surface The convection equivalent source position Convective equivalent source intensity at The sound pressure convection equivalent source model between the first grid node position , the convection equivalent source position and the angular frequency , combined with the second function formula, determine the second convection transfer function ; and according to the second convection transfer function , construct the frequency domain perturbation velocity of the non-closed permeable surface The convection equivalent source intensity The acoustic velocity convection equivalent source model between the two; according to the sound pressure convection equivalent source model and the acoustic velocity convection equivalent source model, determining the convection equivalent source position Convective equivalent source intensity at ; According to the position of the far-field observation point , the convection equivalent source position , the angular frequency , and the convective equivalent source intensity , determine the sound pressure at the far-field observation point Harmonic Speed ; Wherein, the first function formula is: ; The sound pressure convection equivalent source model is ; represents an imaginary unit; Indicates the location of the first grid node associated with and the convection equivalent source position a frequency-domain convective Green's function for performing two-dimensional aeroacoustic noise prediction or for performing three-dimensional aeroacoustic noise prediction; denotes the frequency-domain convective Green's function at the first grid node position ; the second function is given by: ; and the acoustic-velocity convective equivalent source model is given by: .

[0006] According to the aeroacoustic noise prediction method provided in the embodiments of the present application, when the frequency-domain convective Green's function is used for performing two-dimensional aeroacoustic noise prediction, a uniform flow moves along the axis in a positive direction at a velocity , and the expression form of the frequency-domain convective Green's function is given by: ; wherein denotes the Mach number of the uniform flow moving along the axis in a positive direction; denotes the acoustic velocity in the uniform flow; denotes the zero-order second-type Hankel function; denotes the acoustic radius; denotes the relative position vector between the first grid node position and the convective equivalent source position ; and denotes the distance between the first grid node position and the convective equivalent source position ; and denotes the acoustic wave number; denotes the convective amplification coefficient of the uniform flow.

[0007] According to the aeroacoustic noise prediction method provided in the embodiments of the present application, when the frequency-domain convective Green's function is used for performing three-dimensional aeroacoustic noise prediction, the expression form of the frequency-domain convective Green's function is given by: ; wherein denotes the first acoustic radius; denotes the second acoustic radius; denotes the relative position vector between the first grid node position and the convective equivalent source position ; and denotes the distance between the first grid node position and the convective equivalent source position ; and denotes the Mach number vector of the uniform flow; denotes the acoustic velocity in the uniform flow; denotes the acoustic wave number; denotes the convective amplification coefficient of the uniform flow.

[0008] According to an aerodynamic noise prediction method provided by an embodiment of the present application, the position of the convection equivalent source is determined according to the sound pressure convection equivalent source model and the acoustic velocity convection equivalent source model. Convective equivalent source intensity at , including: converting the first convection transfer function and the second convection transfer function The transfer matrix composed of ; According to the column vector composed of N convection equivalent source intensities, construct the intensity matrix ; According to the column vectors of M frequency domain disturbance pressures and M frequency domain disturbance velocities, construct the frequency domain matrix ; Use numerical methods to solve the coefficient matrix , the intensity matrix and the frequency domain matrix The linear matrix equation constructed to obtain the convection equivalent source intensity ; Wherein, the linear matrix equation is .

[0009] According to an aerodynamic noise prediction method provided in an embodiment of the present application, the position of the far-field observation point is , the convection equivalent source position , the angular frequency , and the convective equivalent source intensity , determine the sound pressure of the far-field observation point Harmonic Speed , including: according to the sound pressure formula, obtaining the sound pressure According to the acoustic velocity formula, the acoustic velocity is obtained ; Wherein, the sound pressure formula is: ; The acoustic velocity formula is: ; represents an imaginary unit; represents the third convection transfer function, represents the velocity vector of the uniform incoming flow, Indicates the association of the location and the convection equivalent source position The frequency domain convection Green's function, represents the frequency domain convection Green's function At the stated location The gradient at represents the fourth convection transfer function According to an embodiment of the present application, a method for predicting aerodynamic noise is provided, the method further comprising: determining the time domain disturbance pressure according to the disturbance pressure calculation formula , and according to the disturbance velocity calculation formula, determine the time domain disturbance velocity ; Using Fourier transform, the time domain disturbance pressure Converted into the frequency domain disturbance pressure , and the time domain perturbation speed Converted into the frequency domain disturbance velocity ; Wherein, the disturbance pressure calculation formula is: ; The disturbance velocity calculation formula is: ; Indicates time; represents the time domain pressure of the non-closed permeable surface; represents the pressure of the uniform incoming flow; represents the time domain velocity of the non-enclosed permeable surface; or , respectively represent the components of two directions in a two-dimensional rectangular coordinate system or the components of three directions in a three-dimensional rectangular coordinate system.

[0010] According to an aerodynamic noise prediction method provided by an embodiment of the present application, the numerical method is used to solve the coefficient matrix , the intensity matrix and the frequency domain matrix The linear matrix equation constructed to obtain the convection equivalent source intensity , including: the coefficient matrix Perform singular value decomposition to obtain a left singular vector matrix, a right singular vector matrix and a singular value matrix; construct a minimized empirical Bayesian regularization function based on the left singular vector matrix, the right singular vector matrix and the singular value matrix; determine a target regularization parameter based on the minimized empirical Bayesian regularization function; solve the linear matrix equation based on the target regularization parameter to obtain the convection equivalent source intensity .

[0011] In a second aspect, the present application provides an aerodynamic noise prediction device, comprising: The grid node determination module is used to divide the non-closed permeable surface to obtain M first grid nodes, and discretize the closed equivalent source surface corresponding to the non-closed permeable surface to obtain N second grid nodes, each second grid node is configured with a convection equivalent source, and M and N are integers greater than 1; wherein, the first The first grid node position is , , No. The convection equivalent source position of the second grid node configuration is , ; Convection equivalent source model building module, used to calculate the convection equivalent source model based on the first grid node position. , convection equivalent source position and angular frequency , combined with the first function formula, determine the first convection transfer function ; and according to the first convection transfer function , construct the frequency domain disturbance pressure of the non-closed permeable surface The convection equivalent source position Convective equivalent source intensity at The sound pressure convection equivalent source model between the first grid node position , the convection equivalent source position and the angular frequency , combined with the second function formula, determine the second convection transfer function ; and according to the second convection transfer function , construct the frequency domain perturbation velocity of the non-closed permeable surface The convection equivalent source intensity Acoustic velocity convection equivalent source model between; A convection equivalent source intensity calculation module is used to determine the convection equivalent source position according to the sound pressure convection equivalent source model and the acoustic velocity convection equivalent source model. Convective equivalent source intensity at ; Far-field noise propagation prediction module is used to predict the noise propagation based on the position of the far-field observation point. , the convection equivalent source position , the angular frequency , and the convective equivalent source intensity , determine the sound pressure of the far-field observation point Harmonic Speed ; The first function formula is: ; The sound pressure convection equivalent source model is: ; represents an imaginary unit; Indicates the location of the first grid node associated with and the convection equivalent source position A frequency domain convective Green's function, wherein the frequency domain convective Green's function is used to perform two-dimensional aerodynamic noise prediction or three-dimensional aerodynamic noise prediction; represents the frequency domain convection Green's function At the first grid node position The gradient at The second function formula is: ; The acoustic velocity convection equivalent source model is: .

[0012] In a third aspect, the present application also provides an electronic device comprising a processor and a memory, wherein the memory stores computer instructions, and the processor is used to execute the computer instructions stored in the memory. When the computer instructions are executed by the processor, the electronic device implements the aerodynamic noise prediction method as described in any one of the first aspects above.

[0013] In a fourth aspect, the present application further provides a computer-readable storage medium having computer-executable instructions stored thereon. When the computer-executable instructions are executed, the aerodynamic noise prediction method as described in any one of the above-mentioned first aspects is implemented.

[0014] In a fifth aspect, the present application further provides a computer program product, which includes program instructions. When the program instructions are run on a computer, the aerodynamic noise prediction method as described in any one of the first aspects above is executed.

[0015] The present application provides an aerodynamic noise prediction method, device and electronic device, which divides a non-closed permeable surface to obtain M first grid nodes, and discretizes the closed equivalent source surface corresponding to the non-closed permeable surface to obtain N second grid nodes, each of which is configured with a convection equivalent source, where M and N are integers greater than 1; wherein, The first grid node position is , , No. The convection equivalent source position of the second grid node configuration is , ; According to the first grid node position , convection equivalent source position and angular frequency , combined with the first function formula, determine the first convection transfer function ; and according to the first convection transfer function , construct the frequency domain disturbance pressure of the non-closed permeable surface The convection equivalent source position Convective equivalent source intensity at The sound pressure convection equivalent source model between the first grid node position , the convection equivalent source position and the angular frequency , and a second function formula is used to determine a second pair of convection transfer functions ; and a second pair of convection transfer functions are determined according to the second pair of convection transfer functions , a sound pressure convection equivalent source model between the non-enclosed permeable surface pressure and the convection equivalent source strength is constructed; and a convection equivalent source strength at the convection equivalent source position is determined according to the sound pressure convection equivalent source model and the acoustic velocity convection equivalent source model; and a sound pressure and an acoustic velocity of a far-field observation point are determined according to a position of the far-field observation point, the convection equivalent source position , the angular frequency , and the convection equivalent source strength ; wherein the first function formula is: ; represents an imaginary unit; represents a frequency-domain convection Green function associated with the first grid node position and the convection equivalent source position , and the frequency-domain convection Green function is used for two-dimensional aerodynamic noise prediction or three-dimensional aerodynamic noise prediction; represents a gradient of the frequency-domain convection Green function at the first grid node position ; the second function formula is: ; and the acoustic velocity convection equivalent source model is: .

[0016] The entire process is based on non-enclosed permeable surface pressure and velocity data without turbulent fluctuation components, and far-field sound pressure and acoustic velocity are predicted by constructing a convection equivalent source model, which can effectively avoid the permeable surface pseudo-sound radiation phenomenon and realize aerodynamic sound field prediction without pseudo-sound pollution compared with the sound analogy method based on the enclosed permeable surface data; and the influence of the convection effect of the moving medium on sound propagation is considered compared with the sound field reconstruction method based on the equivalent source, and the method is suitable for aerodynamic sound field prediction in a moving medium. BRIEF DESCRIPTION OF DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments of the present application or the prior art description. Obviously, the drawings described below are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor on the basis of these drawings.

[0018] Figure 1 is a two-dimensional cylindrical flow far-field noise prediction example schematic diagram provided by the embodiment of the application; Figure 2 is a flow schematic diagram of the aerodynamic noise prediction method provided by the embodiment of the application; Figure 3 is a comparison diagram of the sound pressure directional distribution results calculated by different aerodynamic noise prediction methods provided by the embodiment of the application; Figure 4 is a comparison diagram of the sound pressure time history results calculated by different aerodynamic noise prediction methods provided by the embodiment of the application; Figure 5 is a comparison diagram of the acoustic velocity directional distribution results calculated by different aerodynamic noise prediction methods provided by the embodiment of the application; Figure 6 is a comparison diagram of the acoustic velocity time history results calculated by different aerodynamic noise prediction methods provided by the embodiment of the application; Figure 7 is a structural schematic diagram of the aerodynamic noise prediction device provided by the embodiment of the application; Figure 8 is a structural schematic diagram of the electronic device provided by the embodiment of the application. DETAILED DESCRIPTION

[0019] In order to make the purpose, technical scheme and advantages of the present application clearer, the technical scheme in the present application will be described clearly and completely in combination with the drawings in the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of protection of the present application.

[0020] In order to better understand the embodiments of the present application, the background art is first described in detail: ​​​​In the field of aeroacoustics, the prior art uses three types of methods to suppress the false noise pollution based on the acoustic analogy method, but the effect is very limited. The first type of method suppresses false noise by windowing the volume source term, and the window function includes a multi-permeable surface window, a smooth change area window, a step transition area window and an infinitely thin thickness window. The theoretical basis of the volume source term windowing method is insufficient, and the numerical precision is limited. The second type of method filters the turbulent fluctuations by using the divergence of the perturbation velocity and the material derivative to suppress false noise by modifying the source term of the acoustic control equation. This method requires that there be no obvious pressure and density perturbations induced by turbulent fluctuations at the permeable surface, which is difficult to apply to engineering practical problems. The third type of method discards the patch area of the permeable surface that allows turbulent fluctuations to pass through, and predicts noise by data integration of the non-enclosed permeable surface. The acoustic analogy integral equation requires the permeable surface to be closed, and the mathematical basis of integrating data based on a non-enclosed permeable surface is not established. That is, the above false noise suppression methods are only suitable for acoustic pressure false noise suppression, and the false noise suppression method for acoustic velocity has not been studied, so it is impossible to effectively avoid the false noise radiation phenomenon of the acoustic velocity at the permeable surface.

[0021] In the field of traditional acoustics, the existing sound field reconstruction method is based on the equivalent source assumption, and the sound field in a wide space range is predicted by using the equivalent source principle according to the local sound field information. In theory, if the perturbation flow field of the non-enclosed permeable surface is regarded as a local sound field, the sound field reconstruction method can be used to predict the false-free propagation of the far-field aeroacoustic field. However, the existing sound field reconstruction method is only used to predict the sound pressure, and is not suitable for acoustic velocity extrapolation. More importantly, the existing sound field reconstruction method requires the sound propagation medium to be in a stationary state, while for acoustic problems such as flow around and mixed jet, the aeroacoustic noise propagates in a moving medium, and at this time the influence of the moving medium on the flow effect of the far-field sound field must be considered. Therefore, the existing sound field reconstruction method based on the equivalent source is difficult to apply to the suppression of false noise radiation of the permeable surface.

[0022] To solve the above technical problems, the embodiments of the present application provide an aeroacoustic noise prediction method, which divides a non-enclosed permeable surface to obtain M first grid nodes, and discretizes a corresponding closed equivalent source surface inside the non-enclosed permeable surface to obtain N second grid nodes, each of which is configured with a convective equivalent source, and M and N are integers greater than 1; wherein the position of the first grid node is , , , and the position of the convective equivalent source configured by the second grid node is , , ; according to the first grid node position , the convective equivalent source position and the angular frequency , a first convective transfer function is determined by combining a first function formula ; and according to the first convection transfer function , construct the frequency domain disturbance pressure of the non-closed permeable surface The convection equivalent source position Convective equivalent source intensity at The sound pressure convection equivalent source model between the first grid node position , the convection equivalent source position and the angular frequency , combined with the second function formula, determine the second convection transfer function ; and according to the second convection transfer function , construct the frequency domain perturbation velocity of the non-closed permeable surface The convection equivalent source intensity The acoustic velocity convection equivalent source model between the two; according to the sound pressure convection equivalent source model and the acoustic velocity convection equivalent source model, determining the convection equivalent source position Convective equivalent source intensity at ; According to the position of the far-field observation point , the convection equivalent source position , the angular frequency , and the convective equivalent source intensity , determine the sound pressure at the far-field observation point Harmonic Speed The whole process is based on the pressure and velocity data of non-enclosed permeable surfaces without turbulent pulsation components. By constructing a convective equivalent source model to predict the far-field sound pressure and acoustic velocity, compared with the sound analogy method based on closed permeable surface data, it can effectively avoid the pseudo-sound radiation phenomenon of the permeable surface and realize the prediction of aerodynamic sound field without pseudo-sound pollution. Compared with the sound field reconstruction method based on equivalent source, it takes into account the influence of the convection effect of the moving medium on the sound propagation, and is suitable for the prediction of aerodynamic sound field in the moving medium.

[0023] It should be noted that the aerodynamic noise prediction method provided in the embodiments of the present application can be implemented by an aerodynamic noise prediction device or an electronic device, and is not specifically limited here. The following example illustrates the aerodynamic noise prediction method provided in the embodiments of the present application, using an electronic device as the implementation entity, for the far-field noise prediction process of a two-dimensional cylindrical flow: For example, Figure 1 The figure is a schematic diagram of a two-dimensional cylinder flow far-field noise prediction example provided in the embodiment of the present application. Figure 1 In the figure, 1 represents a two-dimensional uniform flow; 2 represents a two-dimensional cylinder; 3 represents a non-enclosed permeable surface. ; 4 represents a closed equivalent source surface ; 5 represents a closed permeable surface ; 6 represents the position of the far-field observation point ; 7 represents the radius of the far-field observation point ; 8 represents the angle of the far-field observation point .

[0024] Combining Figure 1 : density and pressure Two-dimensional uniform inflow with Mach number around a cylinder with diameter ; the center of the cylinder is located at the coordinate origin, and the Reynolds number based on the diameter of the cylinder is 150; the sound speed in the uniform inflow ; the far-field observation point is located on a circle with the coordinate origin as the center and a radius of . The geometric angle between the far-field observation point measured based on the axis and the coordinate origin is the observation angle . In the two-dimensional rectangular coordinate system, the position of the far-field observation point is , and all represent the coordinate values of the far-field observation point in the two-dimensional Cartesian coordinate system.

[0025] The aerodynamic noise prediction method provided by the embodiments of the present application will be described in detail below: As shown in Figure 2 , it is a flowchart of the aerodynamic noise prediction method provided by the embodiments of the present application. In Figure 2 , the method can include the following steps: 201. Divide the non-closed permeable surface to obtain M first grid nodes, and discretize the corresponding closed equivalent source surface inside the non-closed permeable surface to obtain N second grid nodes, each of which is configured with a convective equivalent source, M and N are integers greater than 1; wherein the position of the first grid node is , , , and the position of the second grid node configured with a convective equivalent source is , , .

[0026] Wherein, the above-mentioned non-closed permeable surface usually refers to a non-physical, non-closed boundary curved surface or plane, which can allow fluid (including sound waves) to pass freely.

[0027] The above-mentioned closed equivalent source surface is a non-physical and closed curved surface or plane discretized by a series of second grid nodes, and by arranging convective equivalent sources (such as monopoles) on all second grid nodes, the thermal field, acoustic field, etc. radiated by these convective equivalent sources can be completely equivalent to the radiation field of the actual complex source (such as a heat source, a sound source) in the far field or a specific area.

[0028] The convection equivalent source refers to an equivalent source considering the convection effect of the uniform incoming flow. If the velocity of the uniform incoming flow is zero, the convection equivalent source can be determined as the equivalent source. The spatial coordinates of the second grid nodes obtained by discretizing the closed equivalent source surface are the positions of the convection equivalent sources disposed at the second grid nodes. It should be noted that the selection of the positions of the convection equivalent sources directly affects the approximation accuracy of the convection equivalent sources to the actual sources.

[0029] The uniform incoming flow refers to a steady-state background flow field formed by the fluid moving at a constant first flow data outside the permeable surface.

[0030] Optionally, the M first grid nodes can be obtained by uniformly dividing the non-closed permeable surface by the electronic device.

[0031] It should be noted that the timing of determining the M first grid nodes and the N second grid nodes by the electronic device is not limited.

[0032] Optionally, before step 201, the method can further include: determining, by the electronic device, a frequency domain disturbance flow field of the non-closed permeable surface according to a first flow data of the uniform incoming flow and a second flow data of the non-closed permeable surface.

[0033] The first flow data is used to represent the basic parameters of the uniform incoming flow. Optionally, the first flow data can include the pressure and velocity of the uniform incoming flow.

[0034] The second flow data is used to represent the time domain motion parameters of the fluid at the non-closed permeable surface. Optionally, the second flow data can include the time domain pressure and time domain velocity of the fluid at the non-closed permeable surface.

[0035] The frequency domain disturbance flow field refers to the frequency domain value of the fluctuation of the non-closed permeable surface transient flow field relative to the uniform incoming flow steady flow field, and the frequency domain disturbance flow field does not contain obvious turbulent fluctuation components. Optionally, the frequency domain disturbance flow field can include the frequency domain disturbance pressure and frequency domain disturbance velocity of the fluid at the non-closed permeable surface.

[0036] It should be noted that the timing of determining the first flow data and the second flow data by the electronic device is not limited.

[0037] In some embodiments, before step 201, the method can further include: determining, by the electronic device, a time domain disturbance pressure according to a disturbance pressure calculation formula, and determining a time domain disturbance velocity ; the electronic device converts the time-domain disturbance pressure into a frequency-domain disturbance pressure , and converts the time-domain disturbance velocity into a frequency-domain disturbance velocity .

[0038] wherein the disturbance pressure calculation formula is: ; the disturbance velocity calculation formula is: ; denotes time; denotes the time-domain pressure of the non-enclosed permeable surface; denotes the pressure of the uniform incoming flow; denotes the time-domain velocity of the non-enclosed permeable surface; the subscript or respectively denote the two-directional components in a two-dimensional rectangular coordinate system or the three-directional components in a three-dimensional rectangular coordinate system.

[0039] It should be noted that the Fourier transform described above refers to a mathematical tool for decomposing a time-domain signal into superimposed sine / cosine waves of different frequencies, for analyzing the frequency spectrum characteristics of the signal.

[0040] In the embodiments of the present application, in the process in which the electronic device determines the frequency-domain disturbance flow field of the non-enclosed permeable surface according to the first flow data of the uniform incoming flow and the second flow data of the non-enclosed permeable surface, the time-domain disturbance pressure may be determined according to the disturbance pressure calculation formula, and then the Fourier transform is used to convert the time-domain disturbance pressure into a frequency-domain disturbance pressure . Meanwhile, the time-domain disturbance velocity may be determined according to the disturbance velocity calculation formula, and then the Fourier transform is used to convert the time-domain disturbance velocity into a frequency-domain disturbance velocity .

[0041] It should be noted that the time sequence of the determination of the time-domain disturbance pressure and the time-domain disturbance velocity by the electronic device is not limited.

[0042] Optionally, the process of constituting the non-enclosed permeable surface is as follows: according to the high-precision numerical results of compressible flow, M first grid nodes in the flow field that do not contain obvious turbulent fluctuation components are selected, and the non-enclosed permeable surface is constituted according to the M first grid nodes.

[0043] The high-precision numerical result of the compressible flow refers to a flow field solution satisfying a high-precision requirement obtained by solving a Navier-Stokes equation or an Euler equation of the compressible flow through a computational fluid dynamics (CFD) method.

[0044] It should be noted that the frequency domain disturbance flow field of the non-closed permeable surface involved in the embodiments of the present application can be regarded as containing only an acoustic component.

[0045] Exemplarily, in combination with Figure 1 , the electronic device can select the upper edge and the lower edge of the rectangle to form the non-closed permeable surface , the vertical distance of the two edges from the coordinate origin is 1.5 m, and the vertical distance of the left side and the right side from the coordinate origin is 1.5 m and 4 m, respectively. Both edges are uniformly discretized by 111 first grid nodes, so that the total number of first grid nodes on the non-closed permeable surface is 222. Based on the fine discrete grid and the high-order space-time discrete format for solving the Navier-Stokes equation of the compressible flow, the two-dimensional circular flow is simulated to obtain a high-precision flow field solution. The flow calculation time step is 0.0001 s, and the transient pressure data and the transient velocity data of the non-closed permeable surface are output after the calculation converges. The electronic device can extract the first grid node position on the non-closed permeable surface and the corresponding time domain disturbance pressure and time domain disturbance velocity , . Then, the electronic device respectively performs Fourier transform on the time domain disturbance pressure and the time domain disturbance velocity to obtain the frequency domain disturbance pressure and the frequency domain disturbance velocity for subsequent construction of the equivalent source model.

[0046] Optionally, the electronic device discretizes the corresponding closed equivalent source surface inside the non-closed permeable surface to obtain N second grid nodes, which can include: the electronic device arranges a closed equivalent source surface surrounding the generation, reflection and refraction of aerodynamic noise inside the non-closed permeable surface according to the shape characteristics of the non-closed permeable surface; and the electronic device discretizes the closed equivalent source surface to obtain N second grid nodes.

[0047] In the embodiments of the present application, the electronic device constructs a closed equivalent source surface inside the non-closed permeable surface surrounding the generation, reflection and refraction of the aerodynamic noise and other main physical processes, and then in the closed equivalent source plane is discretized to obtain N second grid nodes, and each second grid node is configured with a convection equivalent source, and each convection equivalent source corresponds to a convection equivalent source position, based on which the electronic device can determine N equivalent source positions. Specifically, the electronic device determines the non-closed permeable surface , and then arranges a closed equivalent source plane inside the non-closed permeable surface according to the shape characteristics of the non-closed permeable surface ; then the electronic device determines the size of the closed equivalent source plane , which is used to represent the geometric range of the closed equivalent source plane , and based on the size, the closed equivalent source plane is discretized into N second grid nodes, and then one convection equivalent source is arranged at each of the N second grid nodes to obtain N equivalent source positions.

[0048] It should be noted that for two-dimensional aerodynamic noise prediction, ; for three-dimensional aerodynamic noise prediction, , so as to effectively construct a linear matrix equation in the subsequent process.

[0049] Exemplarily, in combination with Figure 1 , the closed equivalent source plane is located inside the non-closed permeable surface , and the closed equivalent source plane is composed of four sides of a rectangle, wherein the vertical distance of the left side and the right side from the coordinate origin is 1m and 3.5m respectively, and the vertical distance of the upper side and the lower side from the coordinate origin is 1m. The closed equivalent source plane is uniformly arranged with 340 convection equivalent sources.

[0050] 202、According to the first grid node position , the convection equivalent source position and the angular frequency , a first convection transfer function is determined in combination with a first function formula, and a sound pressure convection equivalent source model between the frequency domain disturbance pressure of the non-closed permeable surface and the convection equivalent source intensity at the convection equivalent source position is constructed according to the first convection transfer function .

[0051] wherein the first function formula is: ; The sound pressure to the convective equivalent source model is ; denotes an imaginary unit; denotes a frequency domain convective Green function associated with the first grid node position and the convective equivalent source position , and the frequency domain convective Green function is used for two-dimensional aerodynamic noise prediction or three-dimensional aerodynamic noise prediction; denotes the frequency domain convective Green function at the first grid node position .

[0052] wherein the sound pressure to the convective equivalent source model is used to describe the convective transfer relationship between the frequency domain disturbance pressure and the convective equivalent source intensity .

[0053] In the embodiments of the present application, after the electronic device determines the first grid node position , the convective equivalent source position , and the angular frequency , the electronic device determines the first convective transfer function based on the three parameters and in combination with the first function formula, and then constructs the sound pressure to the convective equivalent source model based on the first convective transfer function .

[0054] It should be noted that the frequency domain convective Green function has different expression forms in two-dimensional aerodynamic sound field prediction and three-dimensional aerodynamic sound field prediction; and the gradient of the frequency domain convective Green function at the first grid node position also has different expression forms in two-dimensional aerodynamic sound field prediction and three-dimensional aerodynamic sound field prediction.

[0055] In some embodiments, when the frequency domain convective Green function is used for two-dimensional aerodynamic noise prediction, a uniform flow moves along the axis in the positive direction at a speed , and the expression form of the frequency domain convective Green function is as follows: .

[0056] wherein , denotes the Mach number of the uniform flow moving along the axis in the positive direction; denotes the sound speed in the uniform flow; denotes a zero-order second-type Hankel function; , denotes an acoustic radius; , represents the relative position vector between the first grid node position and the convective equivalent source position ; , represents the distance between the first grid node position and the convective equivalent source position ; , represents the acoustic wave number; , represents the convective amplification factor of the uniform incoming flow.

[0057] In some embodiments, when the frequency-domain convective Green function is used for three-dimensional aeroacoustic noise prediction, the expression of the above-mentioned frequency-domain convective Green function is as follows: .

[0058] wherein, , represents the first acoustic radius; , represents the second acoustic radius; , represents the relative position vector between the first grid node position and the convective equivalent source position ; , represents the distance between the first grid node position and the convective equivalent source position ; , represents the Mach number vector of the uniform incoming flow; , represents the sound speed in the uniform incoming flow; , represents the acoustic wave number; , represents the convective amplification factor of the uniform incoming flow.

[0059] Optionally, when the frequency-domain convective Green function is used for two-dimensional aeroacoustic noise prediction, the gradient calculation formula of the above-mentioned frequency-domain convective Green function in the direction of is as follows: .

[0060] wherein, , represents the gradient parameter; , represents the first component of the first grid node position .

[0061] Optionally, when the frequency-domain convective Green function is used for two-dimensional aeroacoustic noise prediction, the gradient calculation formula of the above-mentioned frequency-domain convective Green function in the direction of is as follows: .

[0062] wherein, , represents the first-order second kind Hankel function; Indicates the position of the first grid node The second component is different from the first component.

[0063] Optionally, the above gradient parameters The calculation formula is: .

[0064] in, represents the first-order second-kind Hankel function.

[0065] 203. According to the first grid node position , convection equivalent source position and angular frequency , combined with the second function formula, determine the second convection transfer function ; and according to the second convection transfer function , construct the frequency domain perturbation velocity of the non-closed permeable surface Equivalent source intensity to convection Acoustic velocity convection equivalent source model between.

[0066] Among them, the second function formula is: ; The equivalent source model of acoustic velocity convection is: .

[0067] Among them, the above acoustic velocity convection equivalent source model is used to describe the frequency domain disturbance velocity Equivalent source intensity to convection The convection transfer relationship between them.

[0068] In the embodiment of the present application, the electronic device determines the position of the first grid node. , convection equivalent source position , and angular frequency After these three parameters, based on these three parameters and combined with the second function formula, the second convection transfer function is determined , and then the second convection transfer function Based on this, an acoustic velocity convection equivalent source model is constructed.

[0069] 204. Determine the location of the convection equivalent source based on the sound pressure convection equivalent source model and the acoustic velocity convection equivalent source model Convective equivalent source intensity at .

[0070] Among them, the above convective equivalent source intensity It includes the amplitude and phase of the convection equivalent source, which is used to reflect the ability of the convection equivalent source to generate the sound field.

[0071] Next, we determine the location of the convection equivalent source for electronic equipment based on the sound pressure convection equivalent source model and the acoustic velocity convection equivalent source model. Convective equivalent source intensity at To elaborate: In some embodiments, the electronic device determines the convection equivalent source position according to the sound pressure convection equivalent source model and the acoustic velocity convection equivalent source model. Convective equivalent source intensity at , which may include: the electronic device converting the first convection transfer function and the second convection transfer function The transfer matrix composed of The electronic device constructs an intensity matrix based on the column vector composed of N convection equivalent source intensities The electronic device constructs a frequency domain matrix based on the column vectors of M frequency domain disturbance pressures and M frequency domain disturbance velocities. ; The electronic device uses numerical methods to solve the coefficient matrix , intensity matrix and frequency domain matrix The linear matrix equation constructed is used to obtain the convection equivalent source intensity .

[0072] Among them, the linear matrix equation is .

[0073] Specifically, the intensity matrix ; Coefficient matrix ; Frequency domain matrix .

[0074] Among them, the coefficient matrix The specific forms of each sub-matrix in are as follows: =1,2; ; .

[0075] Among them, the frequency domain matrix The specific forms of each sub-matrix in are as follows: =1,2; ; .

[0076] In some embodiments, the electronic device uses a numerical method to solve the coefficient matrix , intensity matrix and frequency domain matrix The linear matrix equation constructed is used to obtain the convection equivalent source intensity The electronic device can perform singular value decomposition on the coefficient matrix to obtain a left singular vector matrix, a right singular vector matrix, and a singular value matrix. The electronic device can construct a minimum empirical Bayes regularization function based on the left singular vector matrix, the right singular vector matrix, and the singular value matrix. The electronic device can determine a target regularization parameter based on the minimum empirical Bayes regularization function. The electronic device can solve the linear matrix equation based on the target regularization parameter to obtain the equivalent source strength of the flow. .

[0077] In the embodiments of the present application, the electronic device can first perform singular value decomposition on the coefficient matrix to obtain a left singular vector matrix , a right singular vector matrix , and a singular value matrix . Wherein, , H represents conjugate transpose. Then, the electronic device can construct a minimum empirical Bayes regularization function based on the left singular vector matrix , the right singular vector matrix , and the singular value matrix . At this time, the expression of the minimum empirical Bayes regularization function is: .

[0078] Wherein, represents the minimum empirical Bayes regularization function, represents the regularization parameter; represents the number of rows of the coefficient matrix , in the embodiments of the present application, ; represents the summation index; represents the singular value in the singular value matrix ; represents the Fourier parameter. Optionally, the Fourier parameter can be calculated by using a first parameter formula, wherein the first parameter formula is: ; represents the conjugate transpose of the column in the left singular vector matrix .

[0079] Then, the electronic device can determine a target regularization parameter based on the minimum empirical Bayes regularization function. Optionally, the target regularization parameter can be calculated by using a second parameter formula, wherein the second parameter formula is: .

[0080] ​​Finally, the electronic device solves the linear matrix equation based on the target regularization parameter to obtain the convection equivalent source intensity. Optionally, the electronic device uses the target formula to solve the linear matrix equation to obtain the convection equivalent source intensity , where the target formula is: ; Represents the identity matrix.

[0081] 205. According to the position of the far-field observation point , convection equivalent source position , angular frequency , and the convection equivalent source intensity , determine the sound pressure at the far-field observation point Harmonic Speed .

[0082] Among them, the above sound pressure Represents the portion of pressure fluctuation caused by acoustic disturbance.

[0083] The above acoustic velocity It represents the vibration velocity of fluid medium particles caused by sound wave disturbance.

[0084] The following is the position of the electronic device according to the far field observation point , convection equivalent source position , angular frequency , and the convection equivalent source intensity , determine the sound pressure at the far-field observation point Harmonic Speed To elaborate: In some embodiments, the electronic device is based on the position of the far-field observation point. , convection equivalent source position , angular frequency , and the convection equivalent source intensity , determine the sound pressure at the far-field observation point Harmonic Speed , which may include: electronic equipment obtains sound pressure according to the sound pressure formula ; The electronic device obtains the acoustic velocity according to the acoustic velocity formula .

[0085] The sound pressure formula is: ; The formula for acoustic velocity is: ; represents an imaginary unit; represents the third convection transfer function, represents the velocity vector of the uniform incoming flow, Indicates the associated location and the location of the convective equivalent source the frequency-domain convective Green's function, denotes the frequency-domain convective Green's function the gradient at the location . denotes the fourth convective transfer function It should be noted that the frequency-domain convective Green's function has different expressions in the two-dimensional aerodynamic sound field prediction and the three-dimensional aerodynamic sound field prediction; the gradient of the frequency-domain convective Green's function at the location also has different expressions in the two-dimensional aerodynamic sound field prediction and the three-dimensional aerodynamic sound field prediction.

[0086] Specifically, when the frequency-domain convective Green's function is used for two-dimensional aerodynamic noise prediction, the uniform flow moves forward along the axis at a speed , and the expression of the frequency-domain convective Green's function is: .

[0087] wherein, denotes the Mach number of the uniform flow moving forward along the axis; denotes the sound speed in the uniform flow; denotes the zero-order second-type Hankel function; denotes the acoustic radius; denotes the relative position vector between the location and the location of the convective equivalent source ; denotes the distance between the location and the location of the convective equivalent source ; denotes the acoustic wave number; denotes the convective amplification coefficient of the uniform flow.

[0088] Specifically, when the frequency-domain convective Green's function is used for three-dimensional aerodynamic noise prediction, the expression of the frequency-domain convective Green's function is: .

[0089] wherein, denotes the first acoustic radius; denotes the second acoustic radius; denotes the relative position vector between the location and the location of the convective equivalent source ; denotes the distance between the location Convection equivalent source position the distance between them; , represents the Mach number vector of the uniform incoming flow; represents the speed of sound in uniform incoming flow; , represents the acoustic wave number; , which represents the convection amplification coefficient of the uniform incoming flow.

[0090] Optionally, when the frequency domain convective Green's function is used to predict two-dimensional aerodynamic noise, the frequency domain convective Green's function along The formula for calculating the directional gradient is: .

[0091] Optionally, when the frequency domain convective Green's function is used to predict two-dimensional aerodynamic noise, the frequency domain convective Green's function along The formula for calculating the directional gradient is: .

[0092] In summary, in order to verify the reliability of the aerodynamic noise prediction method provided in the embodiment of the present application in suppressing the pseudo-noise of the permeable surface, for the two-dimensional aeroacoustic process, Figure 1 In the scenario shown, the aerodynamic noise prediction method provided in the embodiment of the present application is verified, and the specific verification results can be shown as follows: Figure 3-6 shown.

[0093] Specifically, if Figure 3 As shown, the different aerodynamic noise prediction methods provided in the embodiment of the present application are calculated. Comparison of the sound pressure directivity distribution results at . Figure 3 In the figure, curve 9 represents the calculation result of the high-precision CFD method for the sound pressure directivity distribution; curve 10 represents the numerical solution of the closed permeable surface acoustic analogy method for the sound pressure directivity distribution; curve 11 represents the numerical solution of the traditional equivalent source sound field reconstruction method for the sound pressure directivity distribution; curve 12 represents the numerical solution of the aerodynamic noise prediction method provided by the embodiment of the present application for the sound pressure directivity distribution. As a supplement, Figure 4 As shown, the different aerodynamic noise prediction methods provided in the embodiment of the present application are calculated. Comparison of the sound pressure time history results at . Figure 4 In the figure, curve 13 represents the calculation result of the high-precision CFD method of the sound pressure time history; curve 14 represents the numerical solution of the closed permeable surface acoustic analogy method of the sound pressure time history; curve 15 represents the numerical solution of the traditional equivalent source sound field reconstruction method of the sound pressure time history; curve 16 represents the numerical solution of the aerodynamic noise prediction method provided by the embodiment of the present application of the sound pressure time history.

[0094] For example, Figure 5As shown, the different aerodynamic noise prediction methods provided in the embodiment of the present application are calculated. Comparison of acoustic velocity directivity distribution results at . Figure 5 In the figure, curve 17 represents The high-precision CFD calculation results of the directional acoustic velocity directivity distribution; Curve 18 shows The numerical solution of the aerodynamic noise prediction method provided by the embodiment of the present application for the directional acoustic velocity directivity distribution; Curve 19 represents The high-precision CFD calculation results of the directional acoustic velocity directivity distribution; Curve 20 shows The numerical solution of the aerodynamic noise prediction method provided by the embodiment of the present application for the directional acoustic velocity directivity distribution. As a supplement, Figure 6 As shown, the different aerodynamic noise prediction methods provided in the embodiment of the present application are calculated. Comparison of acoustic velocity time history results at . Figure 6 In the figure, curve 21 represents The high-precision CFD calculation results of the directional acoustic velocity time history; Curve 22 shows The numerical solution of the aerodynamic noise prediction method provided by the embodiment of the present application for the directional acoustic velocity time history; Curve 23 represents The high-precision CFD calculation results of the directional acoustic velocity time history; Curve 24 shows The embodiment of the present application provides a numerical solution of the aerodynamic noise prediction method for the directional acoustic velocity time history.

[0095] The sound pressure and acoustic velocity calculation results of the high-precision CFD method are used as reference benchmark solutions. Figure 3 and Figure 4 It shows that due to the turbulent pulsation passing through the permeable surface downstream of the flow, the numerical solution of the sound pressure directivity distribution and time history of the closed permeable surface acoustic analogy method has serious pseudo-sound pollution; because the traditional equivalent source sound field reconstruction method does not take into account the convection effect, the predicted results of the sound pressure directivity distribution and time history have obvious deviations; the numerical solution of the sound pressure directivity distribution and time history of the aerodynamic noise prediction method provided in the embodiment of the present application is basically consistent with the calculation results of the high-precision CFD method.

[0096] The closed permeable surface acoustic analogy method and the traditional equivalent source sound field reconstruction method are both unable to predict the acoustic velocity propagation. Therefore, only the numerical solution of the acoustic velocity directivity distribution and time history of the aerodynamic noise prediction method provided in the embodiment of the present application is compared with the calculation results of the high-precision CFD method. Figure 5 and Figure 6 It can be seen that the aerodynamic noise prediction method provided in the embodiment of the present application can obtain prediction results consistent with the high-precision CFD method.

[0097] Figure 3-6 The comparison result shown not only proves the correctness of the aerodynamic noise prediction method provided in the embodiments of the present application, but also embodies the superiority of the aerodynamic noise prediction method provided in the embodiments of the present application.

[0098] In the embodiments of the present application, the technical solutions provided in steps 201-205 are based on the non-enclosed permeable surface pressure and velocity data without the turbulent fluctuation component, and the far-field sound pressure and acoustic velocity are predicted by constructing a convection equivalent source model. Compared with the acoustic analogy method based on the enclosed permeable surface data, the convection equivalent source model can effectively avoid the phenomenon of false sound radiation of the permeable surface and realize the prediction of the aerodynamic sound field without false sound pollution. Compared with the sound field reconstruction method based on the equivalent source, the influence of the convection effect of the moving medium on sound propagation is considered, and the method is suitable for the prediction of the aerodynamic sound field in the moving medium.

[0099] The aerodynamic noise prediction device provided in the embodiments of the present application is described below. The aerodynamic noise prediction device described below can be referred to in conjunction with the aerodynamic noise prediction method described above.

[0100] As shown in FIG. 7, it is a structure schematic diagram of the aerodynamic noise prediction device provided in the embodiments of the present application. The device can include a grid node determination module 701, a convection equivalent source model construction module 702, a convection equivalent source intensity calculation module 703, and a far-field noise propagation prediction module 704. Figure 7 The grid node determination module 701 is configured to divide the non-enclosed permeable surface to obtain M first grid nodes, and discretize the corresponding enclosed equivalent source surface inside the non-enclosed permeable surface to obtain N second grid nodes, each second grid node is configured with a convection equivalent source, and M and N are integers greater than 1; wherein the position of the first grid node is

[0101] The convection equivalent source model construction module 702 is configured to determine a first convection transfer function according to the first grid node position , the convection equivalent source position , and the angular frequency in combination with a first function formula; and construct an acoustic pressure convection equivalent source model between the frequency domain disturbance pressure of the non-enclosed permeable surface and the convection equivalent source intensity at the convection equivalent source position according to the first convection transfer function ; and determine the first grid node position​​​​​​​ , the location of the convective equivalent source , and the angular frequency , in combination with a second function formula, to determine a second convective transfer function ; and according to the second convective transfer function , to construct a frequency-domain perturbation velocity of the non-enclosed permeable surface and an acoustic velocity-to-convective equivalent source model between the intensity of the convective equivalent source a convective equivalent source intensity calculation module 703, configured to determine, according to the sound pressure-to-convective equivalent source model and the acoustic velocity-to-convective equivalent source model, the intensity of the convective equivalent source at the location of the convective equivalent source ; a far-field noise propagation prediction module 704, configured to determine, according to the location of a far-field observation point , the location of the convective equivalent source , the angular frequency , and the intensity of the convective equivalent source , a sound pressure and an acoustic velocity of the far-field observation point; wherein the first function formula is: ; the sound pressure-to-convective equivalent source model is ; denotes an imaginary unit; denotes a frequency-domain convective Green's function associated with the location of the first grid node and the location of the convective equivalent source , the frequency-domain convective Green's function being used for two-dimensional aerodynamic noise prediction or three-dimensional aerodynamic noise prediction; denotes a gradient of the frequency-domain convective Green's function at the location of the first grid node ; the second function formula is: ; the acoustic velocity-to-convective equivalent source model is: .

[0102] Optionally, when the frequency-domain convective Green's function is used for two-dimensional aerodynamic noise prediction, a uniform flow moves along the axis in a positive direction at a speed , and an expression form of the frequency-domain convective Green's function is: ; wherein denotes a Mach number of the uniform flow moving along the axis in a positive direction; denotes a sound speed in the uniform flow; ​denotes the zeroth order second kind Hankel function; denotes the acoustic radius; denotes the relative position vector between the first grid node position and the convective equivalent source position ; denotes the distance between the first grid node position and the convective equivalent source position ; denotes the acoustic wavenumber; denotes the convective amplification factor of the uniform incoming flow.

[0103] Optionally, when the frequency-domain convective Green function is used for three-dimensional aerodynamic noise prediction, the expression form of the frequency-domain convective Green function is: ; wherein, denotes the first acoustic radius; denotes the second acoustic radius; denotes the relative position vector between the first grid node position and the convective equivalent source position ; denotes the distance between the first grid node position and the convective equivalent source position ; denotes the Mach number vector of the uniform incoming flow; denotes the sound speed in the uniform incoming flow; denotes the acoustic wavenumber; denotes the convective amplification factor of the uniform incoming flow.

[0104] Optionally, the convective equivalent source intensity calculation module 703 is specifically configured to: determine a transfer matrix composed of the first convective transfer function and the second convective transfer function as a coefficient matrix ; construct an intensity matrix according to a column vector composed of N convective equivalent source intensities; construct a frequency-domain matrix according to column vectors of M frequency-domain disturbance pressures and M frequency-domain disturbance velocities; and solve a linear matrix equation constructed by the coefficient matrix , the intensity matrix , and the frequency-domain matrix to obtain the convective equivalent source intensity ; wherein the linear matrix equation is .

[0105] Optionally, the far-field noise propagation prediction module 704 is specifically configured to obtain the sound pressure ; according to the acoustic velocity formula, the acoustic velocity ; wherein the sound pressure formula is: ; the acoustic velocity formula is: ; denotes an imaginary unit; denotes a third convective transfer function, denotes a velocity vector of a uniform incoming flow, denotes a frequency-domain convective Green's function associated with the position and the convective equivalent source position ; denotes a gradient of the frequency-domain convective Green's function at the position ; denotes a fourth convective transfer function.

[0106] Optionally, the apparatus can further include a frequency-domain parameter determination module, configured to determine a time-domain perturbation pressure according to a perturbation pressure calculation formula, and determine a time-domain perturbation velocity according to a perturbation velocity calculation formula; convert the time-domain perturbation pressure into the frequency-domain perturbation pressure , and convert the time-domain perturbation velocity into the frequency-domain perturbation velocity ; wherein the perturbation pressure calculation formula is: ; the perturbation velocity calculation formula is: ; denotes time; denotes a time-domain pressure of the non-enclosed permeable surface; denotes a pressure of the uniform incoming flow; denotes a time-domain velocity of the non-enclosed permeable surface; subscripts or denote components in two directions in a two-dimensional rectangular coordinate system or components in three directions in a three-dimensional rectangular coordinate system, respectively.

[0107] Optionally, the convective equivalent source intensity calculation module 703 is specifically configured to perform singular value decomposition on the coefficient matrix to obtain a left singular vector matrix, a right singular vector matrix, and a singular value matrix; construct a minimum empirical Bayes regularization function based on the left singular vector matrix, the right singular vector matrix, and the singular value matrix; determine a target regularization parameter based on the minimum empirical Bayes regularization function; and solve the linear matrix equation based on the target regularization parameter to obtain the convective equivalent source intensity .

[0108] As Figure 8, is a schematic diagram of the structure of an electronic device provided by an embodiment of the present application, the electronic device may include: a processor (processor) 810, a communication interface (Communications Interface) 820, a memory (memory) 830 and a communication bus 840, wherein the processor 810, the communication interface 820, and the memory 830 communicate with each other through the communication bus 840. The processor 810 can call the logic instructions in the memory 830 to execute the aerodynamic noise prediction method, which includes: dividing the non-closed permeable surface to obtain M first grid nodes, and discretizing the closed equivalent source surface corresponding to the inside of the non-closed permeable surface to obtain N second grid nodes, each second grid node is configured with a convection equivalent source, M and N are integers greater than 1; wherein, the first The first grid node position is , , No. The convection equivalent source position of the second grid node configuration is , ; According to the first grid node position , convection equivalent source position and angular frequency , combined with the first function formula, determine the first convection transfer function ; and according to the first convection transfer function , construct the frequency domain disturbance pressure of the non-closed permeable surface The convection equivalent source position Convective equivalent source intensity at The sound pressure convection equivalent source model between the first grid node position , the convection equivalent source position and the angular frequency , combined with the second function formula, determine the second convection transfer function ; and according to the second convection transfer function , construct the frequency domain perturbation velocity of the non-closed permeable surface The convection equivalent source intensity The acoustic velocity convection equivalent source model between the two; according to the sound pressure convection equivalent source model and the acoustic velocity convection equivalent source model, determining the convection equivalent source position Convective equivalent source intensity at ; According to the position of the far-field observation point , the convection equivalent source position , the angular frequency , and the convective equivalent source intensity , determine the sound pressure of the far-field observation point Harmonic Speed ; wherein the first function formula is: ; the acoustic pressure convective source model is ; denotes the imaginary unit; denotes a frequency domain convective Green's function associated with the first grid node position and the convective source position , the frequency domain convective Green's function being used for two-dimensional or three-dimensional aeroacoustic noise prediction; denotes a gradient of the frequency domain convective Green's function at the first grid node position ; the second function formula is: ; the acoustic velocity convective source model is: .

[0109] In addition, the logic instructions in the memory 830 described above can be implemented in the form of a software function unit and sold or used as an independent product, and can be stored in a computer readable storage medium. Based on this understanding, the technical solutions of the present application essentially or the parts that contribute to the prior art or parts of the technical solutions can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a plurality of instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the method described in the various embodiments of the present application. The aforementioned storage medium includes: a U disk, a mobile hard disk, a read-only memory (Read-Only Memory, ROM), a random access memory (Random Access Memory, RAM), a magnetic disk or an optical disk, and various media that can store program codes.

[0110] In yet another aspect, the present application also provides a non-transitory computer readable storage medium having computer instructions (i.e. software instructions) stored thereon, which are executed by a processor to implement the aeroacoustic noise prediction method provided by the above-mentioned methods.

[0111] In another aspect, the present application also provides a computer instruction product, which includes computer instructions, the computer instructions being stored on a non-transitory computer readable storage medium, and the computer instructions being executed by a processor to enable a computer to execute the aeroacoustic noise prediction method provided by the above-mentioned methods.

[0112] The device embodiments described above are merely illustrative, wherein the units described as separate components can or can not be physically separate, and the components displayed as units can or can not be physical units, i.e., can be located in one place, or can be distributed to multiple network units. Part or all of the modules can be selected to achieve the purposes of the embodiments according to actual needs. Those skilled in the art can understand and implement without creative labor.

[0113] Through the description of the above embodiments, those skilled in the art can clearly understand that the embodiments can be realized by means of software and the necessary general hardware platform, and of course can also be realized by hardware. Based on such understanding, the above technical solutions can be embodied in the form of software products, and the computer software products can be stored in a computer readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and include a plurality of instructions to make a computer device (which can be a personal computer, a server, or a network device, etc.) execute the methods described in each embodiment or some parts of the embodiments.

[0114] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for predicting aerodynamic noise, characterized in that: include: The non-closed permeable surface is divided to obtain M first grid nodes, and the closed equivalent source surface corresponding to the non-closed permeable surface is discretized to obtain N second grid nodes, each of which is configured with a convection equivalent source, where M and N are integers greater than 1; wherein, The first grid node position is , , No. The convection equivalent source position of the second grid node configuration is , ; According to the first grid node position , convection equivalent source position and angular frequency , combined with the first function formula, determine the first convection transfer function ; and according to the first convection transfer function , construct the frequency domain disturbance pressure of the non-closed permeable surface The convection equivalent source position Convective equivalent source intensity at The sound pressure convection equivalent source model between them; According to the first grid node position , the convection equivalent source position and the angular frequency , combined with the second function formula, determine the second convection transfer function ; and according to the second convection transfer function , construct the frequency domain perturbation velocity of the non-closed permeable surface The convection equivalent source intensity Acoustic velocity convection equivalent source model between; Determine the position of the convection equivalent source according to the sound pressure convection equivalent source model and the acoustic velocity convection equivalent source model Convective equivalent source intensity at ; According to the position of the far-field observation point , the convection equivalent source position , the angular frequency , and the convective equivalent source intensity , determine the sound pressure of the far-field observation point Harmonic Speed ; The first function formula is: ; The sound pressure convection equivalent source model is: ; represents an imaginary unit; Indicates the location of the first grid node associated with and the convection equivalent source position A frequency domain convective Green's function, wherein the frequency domain convective Green's function is used to perform two-dimensional aerodynamic noise prediction or three-dimensional aerodynamic noise prediction; represents the frequency domain convection Green's function At the first grid node position The gradient at The second function formula is: ; The acoustic velocity convection equivalent source model is: .

2. The aerodynamic noise prediction method according to claim 1, characterized in that: When the frequency domain convective Green's function is used to predict two-dimensional aerodynamic noise, the uniform incoming flow along Axis positive direction at speed Motion, the frequency domain convection Green's function is expressed as: ; in, , indicating uniform incoming flow along Mach number of the axis in the positive direction; It represents the speed of sound in uniform incoming flow; represents the zero-order second-kind Hankel function; , represents the acoustic radius; , represents the position of the first grid node and the convection equivalent source position The relative position vector between them; , represents the position of the first grid node and the convection equivalent source position the distance between them; , represents the acoustic wave number; , which represents the convection amplification coefficient of the uniform incoming flow.

3. The aerodynamic noise prediction method according to claim 1, characterized in that: When the frequency domain convective Green's function is used to predict three-dimensional aerodynamic noise, the frequency domain convective Green's function is expressed as: ; in, , represents the first acoustic radius; , represents the second acoustic radius; , represents the position of the first grid node and the convection equivalent source position The relative position vector between them; , represents the position of the first grid node and the convection equivalent source position the distance between them; , represents the Mach number vector of the uniform incoming flow; It represents the speed of sound in uniform incoming flow; , represents the acoustic wave number; , which represents the convection amplification coefficient of the uniform incoming flow.

4. The aerodynamic noise prediction method according to any one of claims 1 to 3, characterized in that: The position of the convection equivalent source is determined according to the sound pressure convection equivalent source model and the acoustic velocity convection equivalent source model. Convective equivalent source intensity at ,include: The first convection transfer function and the second convection transfer function The transfer matrix composed of ; According to the column vector composed of N convection equivalent source intensities, the intensity matrix is ​​constructed ; According to the column vectors of M frequency domain disturbance pressures and M frequency domain disturbance velocities, the frequency domain matrix is ​​constructed. ; Use numerical methods to solve the coefficient matrix , the intensity matrix and the frequency domain matrix The linear matrix equation constructed to obtain the convection equivalent source intensity ; Among them, the linear matrix equation is .

5. The aerodynamic noise prediction method according to any one of claims 1 to 3, characterized in that: According to the position of the far-field observation point , the convection equivalent source position , the angular frequency , and the convective equivalent source intensity , determine the sound pressure of the far-field observation point Harmonic Speed ,include: According to the sound pressure formula, the sound pressure is obtained ; According to the acoustic velocity formula, the acoustic velocity is obtained ; Wherein, the sound pressure formula is: ; The acoustic velocity formula is: ; represents an imaginary unit; represents the third convection transfer function, represents the velocity vector of the uniform incoming flow, Indicates the association of the location and the convection equivalent source position The frequency domain convection Green's function, represents the frequency domain convection Green's function At the stated location The gradient at represents the fourth convection transfer function.

6. The aerodynamic noise prediction method according to any one of claims 1 to 3, characterized in that: The method further comprises: According to the disturbance pressure calculation formula, determine the time domain disturbance pressure , and according to the disturbance velocity calculation formula, determine the time domain disturbance velocity ; Using Fourier transform, the time domain disturbance pressure Converted into the frequency domain disturbance pressure , and the time domain perturbation speed Converted into the frequency domain disturbance velocity ; The disturbance pressure calculation formula is: ; The disturbance velocity calculation formula is: ; Indicates time; represents the time domain pressure of the non-closed permeable surface; represents the pressure of the uniform incoming flow; represents the time domain velocity of the non-enclosed permeable surface; or , respectively represent the components of two directions in a two-dimensional rectangular coordinate system or the components of three directions in a three-dimensional rectangular coordinate system.

7. The aerodynamic noise prediction method according to claim 4, characterized in that: The numerical method is used to solve the coefficient matrix , the intensity matrix and the frequency domain matrix The linear matrix equation constructed to obtain the convection equivalent source intensity ,include: For the coefficient matrix Perform singular value decomposition to obtain the left singular vector matrix, the right singular vector matrix and the singular value matrix; Constructing a minimized empirical Bayes regularization function based on the left singular vector matrix, the right singular vector matrix, and the singular value matrix; Determining a target regularization parameter based on the minimized empirical Bayesian regularization function; Solve the linear matrix equation based on the target regularization parameter to obtain the convection equivalent source intensity .

8. An aerodynamic noise prediction device, characterized in that: include: The grid node determination module is used to divide the non-closed permeable surface to obtain M first grid nodes, and discretize the closed equivalent source surface corresponding to the non-closed permeable surface to obtain N second grid nodes, each second grid node is configured with a convection equivalent source, and M and N are integers greater than 1; wherein, the first The first grid node position is , , No. The convection equivalent source position of the second grid node configuration is , ; Convection equivalent source model building module, used to calculate the convection equivalent source model based on the first grid node position. , convection equivalent source position and angular frequency , combined with the first function formula, determine the first convection transfer function ; and according to the first convection transfer function , construct the frequency domain disturbance pressure of the non-closed permeable surface The convection equivalent source position Convective equivalent source intensity at The sound pressure convection equivalent source model between the first grid node position , the convection equivalent source position and the angular frequency , combined with the second function formula, determine the second convection transfer function ; and according to the second convection transfer function , construct the frequency domain perturbation velocity of the non-closed permeable surface The convection equivalent source intensity Acoustic velocity convection equivalent source model between; A convection equivalent source intensity calculation module is used to determine the convection equivalent source position according to the sound pressure convection equivalent source model and the acoustic velocity convection equivalent source model. Convective equivalent source intensity at ; Far-field noise propagation prediction module is used to predict the noise propagation based on the position of the far-field observation point. , the convection equivalent source position , the angular frequency , and the convective equivalent source intensity , determine the sound pressure of the far-field observation point Harmonic Speed ; The first function formula is: ; The sound pressure convection equivalent source model is: ; represents an imaginary unit; Indicates the location of the first grid node associated with and the convection equivalent source position A frequency domain convective Green's function, wherein the frequency domain convective Green's function is used to perform two-dimensional aerodynamic noise prediction or three-dimensional aerodynamic noise prediction; represents the frequency domain convection Green's function At the first grid node position The gradient at The second function formula is: ; The acoustic velocity convection equivalent source model is: .

9. An electronic device, characterized in that: The electronic device comprises a processor and a memory, wherein the memory stores computer instructions, and the processor is used to execute the computer instructions stored in the memory. When the computer instructions are executed by the processor, the electronic device implements the aerodynamic noise prediction method according to any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that The computer-readable storage medium stores computer-executable instructions, and when the computer-executable instructions are executed, the aerodynamic noise prediction method according to any one of claims 1 to 7 is implemented.

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