Pneumatic vibration analysis method and system

Abstract

The invention belongs to the field of aviation aerodynamic force analysis, and particularly relates to a pneumatic vibration analysis method and system, a calculation model is gridded to obtain a gridded calculation model, so that calculation is simplified; analyzing the gridding calculation model along with time change to form time domain information, and then converting and contrastively analyzing the time domain information to obtain a pneumatic vibration analysis result of the aerodynamic parameters. Quantitative analysis of aerodynamic parameters is achieved, a large amount of calculation and wind tunnel tests are not needed, flow field characteristic analysis which is time-consuming is not needed either, the calculation cost is low, the calculation precision is high, and mass use can be achieved.

Description

Technical Field

[0001] The present application belongs to the field of aviation aerodynamic analysis, and in particular, relates to a method and system for analyzing aerodynamic vibration. Background Art

[0002] Aircraft will vibrate due to airflow disturbance during flight. There are many reasons for airflow disturbance. On the one hand, it is due to the change of airflow in the atmospheric environment, and on the other hand, it is due to the unstable flow phenomenon formed by the aircraft's own components. In the aircraft design stage, designers are mainly concerned about the second situation. At present, the main means used in aircraft aerodynamic design include wind tunnel tests and numerical simulation methods. Among them, wind tunnel tests are relatively more credible, but there are also problems such as insufficient similarity caused by model reduction that affect accuracy. At the same time, due to the high cost, it is not suitable for large-scale use; numerical simulation methods have been widely used in aerodynamic design in recent years, but they are also mainly focused on solving steady aerodynamic problems. The vibration problem caused by aerodynamics is mainly studied through the flow field characteristic analysis of time-averaged results, and there is a lack of clear constant value analysis methods.

[0003] Therefore, finding a method to quantitatively analyze the vibration problem caused by pneumatics has become a technical problem that needs to be solved urgently in this field. Summary of the invention

[0004] The purpose of this application is to provide a pneumatic vibration analysis method and system to solve the problem that the existing pneumatically caused vibration problem is difficult to quantitatively analyze.

[0005] The technical solution of the present application is: a pneumatic vibration analysis method, comprising:

[0006] The calculation grid is divided according to the calculation model of the analysis object to obtain the grid calculation model; the grid calculation model of the selected analysis object is analyzed by using the unsteady numerical calculation method to obtain the data of the aerodynamic parameters of the analysis object changing with time to form time domain information;

[0007] The time domain information of the analysis object is obtained, the time domain information is analyzed and processed, the time domain information is converted into frequency domain information, and then the frequency domain information is compared and analyzed to obtain the aerodynamic vibration analysis result.

[0008] Preferably, the specific method for obtaining the gridded computational model is: obtaining parameters such as the size of the object of the analysis part and the flight speed of the aircraft in the computational model, determining the grid size, density and grid shape of the computational grid, and completing the computational grid division.

[0009] Preferably, a frontier method is used for computational grid division.

[0010] Preferably, the specific method for obtaining time domain information includes:

[0011] a) Select an appropriate calculation model based on the flow field characteristics;

[0012] b) Determine the calculation time parameters according to the grid calculation model size and the grid size;

[0013] c) Design monitoring parameters based on specific issues.

[0014] Preferably, the time parameters include time step and duration; the monitoring parameters include monitoring components or monitoring positions.

[0015] Preferably, the method for converting time domain information includes:

[0016] a) Obtain the data of aerodynamic parameters of the object under analysis varying with time to form time domain information;

[0017] b) obtaining the amplitude, frequency or phase information of each signal in the time domain information at different frequencies, and converting the time domain information into frequency domain data using spectrum analysis method;

[0018] c) Compare and analyze the frequency domain information based on the frequency characteristics of the main structures of the aircraft.

[0019] As a specific implementation, a pneumatic vibration analysis system includes a model gridding module, a time domain information acquisition module and a frequency domain information analysis module;

[0020] The model gridding module is used to divide the computational grid according to the computational model of the analysis object to obtain a gridded computational model;

[0021] The time domain information acquisition module is used to analyze the gridded calculation model of the selected analysis object using an unsteady numerical calculation method, obtain the data of the aerodynamic parameters of the analysis object changing with time, and form time domain information;

[0022] The frequency domain information analysis module is used to obtain the time domain information of the analysis object, analyze and process the time domain information, convert the time domain information into frequency domain information, and then compare and analyze the frequency domain information to obtain the aerodynamic vibration analysis results.

[0023] Preferably, the specific method for obtaining the gridded computational model is: obtaining parameters such as the size of the object of the analysis part and the flight speed of the aircraft in the computational model, determining the grid size, density and grid shape of the computational grid, and completing the computational grid division.

[0024] Preferably, a frontier method is used for computational grid division.

[0025] Preferably, the specific method for obtaining time domain information includes:

[0026] a) Select an appropriate calculation model based on the flow field characteristics;

[0027] b) Determine the calculation time parameters according to the grid calculation model size and the grid size;

[0028] c) Design monitoring parameters based on specific issues.

[0029] Preferably, the time parameters include time step and duration; the monitoring parameters include monitoring components or monitoring positions.

[0030] Preferably, the method for converting time domain information includes:

[0031] a) Obtain the data of aerodynamic parameters of the object under analysis varying with time to form time domain information;

[0032] b) obtaining the amplitude, frequency or phase information of each signal in the time domain information at different frequencies, and converting the time domain information into frequency domain data using spectrum analysis method;

[0033] c) Compare and analyze the frequency domain information based on the frequency characteristics of the main structures of the aircraft.

[0034] The aerodynamic vibration analysis method and system of the present application grids the calculation model to obtain a gridded calculation model, thereby simplifying the calculation; and analyzes the changes of the gridded calculation model over time to form time domain information, and then converts and compares the time domain information to obtain the aerodynamic vibration analysis results of the aerodynamic parameters. The quantitative analysis of aerodynamic parameters is realized, which can be realized without a large amount of calculation and wind tunnel testing, and does not require a relatively time-consuming flow field characteristic analysis. The calculation cost is low, the calculation accuracy is high, and it can be used in large quantities. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solution provided by the present application, the following is a brief introduction to the accompanying drawings. Obviously, the accompanying drawings described below are only some embodiments of the present application.

[0036] Figure 1 This is a schematic diagram of the overall process of this application;

[0037] Figure 2 This is a schematic diagram of typical aerodynamic time domain information for this application;

[0038] Figure 3 This is a schematic diagram of typical aerodynamic frequency domain information for this application. DETAILED DESCRIPTION

[0039] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0040] A method for analyzing aerodynamic vibrations, such as Figure 1 , including the following steps:

[0041] Step S100, performing computational grid division according to the computational model of the analysis object to obtain a gridded computational model;

[0042] The specific method of obtaining the gridded computational model is: obtaining the parameters such as the size of the object to be analyzed and the flight speed of the aircraft in the computational model, determining the grid size, density and grid shape of the computational grid, and completing the computational grid division. For example, the larger the size of the object to be analyzed, the sparser the grid; the smaller the size of the object to be analyzed, the denser the grid. The grid shapes include rectangles and triangles.

[0043] Preferably, a frontier method is used for computational grid division.

[0044] Step S200, the gridded calculation model of the selected analysis object is analyzed by using an unsteady numerical calculation method to obtain the time-varying data of the aerodynamic parameters of the analysis object to form time domain information, such as Figure 2 ;

[0045] The specific methods for obtaining time domain information include:

[0046] a) Select an appropriate calculation model based on the flow field characteristics;

[0047] b) Determine the time parameters such as the calculation time step and duration according to the grid calculation model size and the grid size;

[0048] c) Design monitoring parameters such as monitoring components or monitoring locations based on specific issues.

[0049] Step S300, obtaining the time domain information of the analysis object, analyzing and processing the time domain information, and converting the time domain information into frequency domain information, such as Figure 3 , and then the aerodynamic vibration analysis results are obtained by comparing and analyzing the frequency domain information.

[0050] Methods for converting time domain information include:

[0051] a) Obtain the data of aerodynamic parameters of the object under analysis varying with time to form time domain information;

[0052] b) obtaining information such as the amplitude, frequency or phase of each signal in the time domain information at different frequencies, and converting the time domain information into frequency domain data using spectrum analysis methods;

[0053] c) Compare and analyze the frequency domain information based on the frequency characteristics of the main structures of the aircraft.

[0054] In summary, the present application grids the computational model to obtain a gridded computational model, thereby simplifying the computation; and analyzes the changes of the gridded computational model over time to form time domain information, and then converts and compares the time domain information to obtain the aerodynamic vibration analysis results of the aerodynamic parameters. The quantitative analysis of aerodynamic parameters is achieved, which does not require a large amount of calculations and wind tunnel tests, nor does it require time-consuming flow field feature analysis. The computational cost is low, the computational accuracy is high, and it can be used in large quantities.

[0055] As a specific implementation, it also includes a pneumatic vibration analysis system, which adopts the above design and includes a model gridding module, a time domain information acquisition module and a frequency domain information analysis module. The model gridding module is used to perform computational grid division according to the computational model of the analysis object to obtain a gridded computational model;

[0056] The time domain information acquisition module is used to analyze the gridded calculation model of the selected analysis object using an unsteady numerical calculation method, obtain the data of the aerodynamic parameters of the analysis object changing with time, and form time domain information;

[0057] The frequency domain information analysis module is used to obtain the time domain information of the analysis object, analyze and process the time domain information, convert the time domain information into frequency domain information, and then compare and analyze the frequency domain information to obtain the aerodynamic vibration analysis results.

[0058] Preferably, the specific method for obtaining the gridded computational model is: obtaining parameters such as the size of the object of the analysis part and the flight speed of the aircraft in the computational model, determining the grid size, density and grid shape of the computational grid, and completing the computational grid division.

[0059] Preferably, a frontier method is used for computational grid division.

[0060] Preferably, the specific method for obtaining time domain information includes:

[0061] a) Select an appropriate calculation model based on the flow field characteristics;

[0062] b) Determine the calculation time parameters according to the grid calculation model size and the grid size;

[0063] c) Design monitoring parameters based on specific issues.

[0064] Preferably, the time parameters include time step and duration; the monitoring parameters include monitoring components or monitoring positions.

[0065] Preferably, the method for converting time domain information includes:

[0066] a) Obtain the data of aerodynamic parameters of the object under analysis varying with time to form time domain information;

[0067] b) obtaining the amplitude, frequency or phase information of each signal in the time domain information at different frequencies, and converting the time domain information into frequency domain data using spectrum analysis method;

[0068] c) Compare and analyze the frequency domain information based on the frequency characteristics of the main structures of the aircraft.

[0069] Finally, it should be noted that: the drawings of the embodiments disclosed in the present invention only involve structures related to the embodiments disclosed in the present invention, and other structures can refer to the general design. In the absence of conflict, the same embodiment and different embodiments of the present invention can be combined with each other;

[0070] Finally: The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A pneumatic vibration analysis method, characterized in that: include: Divide the computational grid according to the computational model of the analyzed object to obtain the grid for numerical simulation; The unsteady numerical calculation method is used to simulate and analyze the computational grid of the selected analysis object, and the aerodynamic parameters of the analysis object are obtained over time to form time domain information. The time domain information of the analysis object is obtained, the time domain information is analyzed and processed, the time domain information is converted into frequency domain information, and then the frequency domain information is compared and analyzed to obtain the aerodynamic vibration analysis result.

2. The pneumatic vibration analysis method according to claim 1, characterized in that: The specific method to obtain the gridded computational model is: obtaining the dimensions of the specific analysis components in the computational model and the parameters such as the flight speed of the aircraft, determining the grid topology, grid size, density and grid shape of the computational grid, and completing the computational grid division.

3. The pneumatic vibration analysis method according to claim 1, characterized in that: The computational meshing is performed using cutting-edge methods.

4. The pneumatic vibration analysis method according to claim 1, characterized in that: The specific methods for obtaining time domain information include: a) Select an appropriate calculation model based on the flow field characteristics; b) Determine the calculation time parameters according to the grid calculation model size and the grid size; c) Design monitoring parameters based on specific issues.

5. The pneumatic vibration analysis method according to claim 4, characterized in that: Time parameters include time step and duration; monitoring parameters include monitoring components or monitoring locations.

6. The pneumatic vibration analysis method according to claim 1, characterized in that: Methods for converting time domain information include: a) Obtain the data of aerodynamic parameters of the object under analysis varying with time to form time domain information; b) obtaining the amplitude, frequency or phase information of each signal in the time domain information at different frequencies, and converting the time domain information into frequency domain data using spectrum analysis method; c) Compare and analyze the frequency domain information based on the frequency characteristics of the main structures of the aircraft.

7. A pneumatic vibration analysis system, using the method according to any one of claims 1 to 6, characterized in that: It includes a model gridding module, a time domain information acquisition module and a frequency domain information analysis module; the model gridding module is used to divide the calculation grid according to the calculation model of the analysis object to obtain a gridded calculation model; The time domain information acquisition module is used to analyze the gridded calculation model of the selected analysis object using an unsteady numerical calculation method, obtain the data of the aerodynamic parameters of the analysis object changing with time, and form time domain information; The frequency domain information analysis module is used to obtain the time domain information of the analysis object, analyze and process the time domain information, convert the time domain information into frequency domain information, and then compare and analyze the frequency domain information to obtain the aerodynamic vibration analysis results.

8. The pneumatic vibration analysis system according to claim 7, characterized in that: The specific method for obtaining the gridded computational model is: obtaining parameters such as the size of the object to be analyzed in the computational model and the flight speed of the aircraft, determining the grid size, density and grid shape of the computational grid, and completing the computational grid division.

9. The pneumatic vibration analysis system according to claim 7, characterized in that: The computational meshing is performed using cutting-edge methods.

10. The pneumatic vibration analysis system according to claim 7, characterized in that: The specific methods for obtaining time domain information include: a) Select an appropriate calculation model based on the flow field characteristics; b) Determine the calculation time parameters according to the grid calculation model size and the grid size; c) Design monitoring parameters based on specific issues.

11. The pneumatic vibration analysis system according to claim 10, characterized in that: Time parameters include time step and duration; monitoring parameters include monitoring components or monitoring locations.

12. The pneumatic vibration analysis system according to claim 7, characterized in that: Methods for converting time domain information include: a) Obtain the data of aerodynamic parameters of the object under analysis varying with time to form time domain information; b) obtaining the amplitude, frequency or phase information of each signal in the time domain information at different frequencies, and converting the time domain information into frequency domain data using spectrum analysis method; c) Compare and analyze the frequency domain information based on the frequency characteristics of the main structures of the aircraft.

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