Aero-engine stress application oscillation combustion characteristic parameter database and construction method

Abstract

The invention belongs to the technical field of electric data processing, and particularly relates to an aero-engine stress application oscillation combustion characteristic parameter database and a construction method, and the method comprises the steps: 1, automatically reading dynamic pressure data and steady-state parameter data in a segmented circulation manner; 2, verifying data validity and correcting time axis alignment of the dynamic pressure data and the steady state data; 3, determining stress application data positioning in the dynamic pressure data and the steady state data on the basis that the angle of the throttle lever is larger than 65 degrees; 4, frequency domain analysis is conducted on the stress application data, and parameters include the sampling rate of 51200 Hz and the sample duration of 1 second; the FFT step length is 0.2 second, Butterworth low-pass filtering is carried out, and the cut-off frequency is 3000Hz; a Hanning window function without an average peak mode; 5, extracting the maximum amplitude H, the frequency value F, the oscillation mode average amplitude H0, the continuity evaluation parameter C, the dynamic pressure pulsation peak Hmax and the maximum pulsation peak data set of each oscillation mode; and 6, inputting a calculation result into a database file according to a format.

Description

Technical Field

[0001] This application belongs to the technical field of electrical data processing, and particularly relates to a database of afterburning oscillating combustion characteristic parameters for an aeroengine and a construction method thereof. Background Art

[0002] During the development of modern aeroengines, afterburning combustion stability has always been an important factor restricting the progress of aeroengine technology. The most common and most destructive combustion instability phenomenon is oscillating combustion. To monitor the occurrence and development process of oscillating combustion, the most effective method currently is to conduct dynamic pressure tests on the afterburner. However, during the data analysis process, although it can truly reflect the main characteristics of oscillating combustion, the data volume is huge, resulting in difficult and inefficient data analysis. More importantly, it cannot be associated with basic parameters such as the throttle lever angle, each fuel circuit, and nozzle area, leading to single information and possible omission of some detailed information. Summary of the Invention

[0003] To solve the above problems, this application provides a method for constructing a database of afterburning oscillating combustion characteristic parameters for an aeroengine, including:

[0004] Step 1: Segmentally and circularly read the automatically read dynamic pressure data and steady-state parameter data;

[0005] Step 2: Verify the data validity and correct the time-axis alignment of the dynamic pressure data and the steady-state data;

[0006] Step 3: Determine the afterburning data location in the dynamic pressure data and the steady-state data based on the throttle lever angle being greater than 65°;

[0007] Step 4: Conduct frequency-domain analysis on the afterburning data, with parameters including: sampling rate 51200Hz, sample duration 1 second; FFT step 0.2 second, Butterworth low-pass filter, cut-off frequency 3000Hz; Hanning window function, no average peak mode;

[0008] Step 5: Extract the maximum amplitude H, frequency value F, average amplitude H0 of the oscillation mode, continuity evaluation parameter C, and the peak value H of the dynamic pressure pulsation max and the maximum pulsation peak data group;

[0009] Step 6: Enter the calculation results into the database file in a formatted manner.

[0010] Preferably, the frequency band range of the oscillation mode includes:

[0011] Mode 1: 200Hz to 300Hz;

[0012] Mode 2: 400Hz to 500Hz;

[0013] Mode 3: 810 Hz to 1010 Hz;

[0014] Mode 4: 1250 Hz to 1450 Hz.

[0015] Preferably, the calculation formula of the continuity evaluation parameter C is as follows:

[0016]

[0017] In the formula, N H represents the number of points where the amplitude of a modal characteristic frequency is greater than H C ;

[0018] N s represents the total number of points obtained by calculating the amplitude of a modal characteristic frequency;

[0019] wherein, H C The calculation formula is as follows:

[0020]

[0021]

[0022] H2 = 5.

[0023] Preferably, in the frequency domain analysis, the amplitude of the characteristic frequency within the preset oscillation modal frequency band is extracted in real time, and the maximum amplitude and the corresponding frequency of each mode are determined by comparison.

[0024] Preferably, the maximum pulsation peak data group includes:

[0025] Dynamic pressure amplitude H max ; Dynamic pressure frequency value F max ; Time t; Throttle lever angle Pd; Afterburner 1-way oil pressure Py1; Afterburner 2-way oil pressure Py2; Afterburner 3-way oil pressure Py3; Afterburner 4-way oil pressure Py4; Nozzle area Ap.

[0026] Preferably, the extraction method of the maximum pulsation peak data group is: identifying the peak moment of the dynamic pressure amplitude in the full frequency band, and synchronously recording the throttle lever angle, oil pressure, nozzle area and time parameters.

[0027] An afterburner oscillation combustion characteristic parameter database for an aeroengine, comprising: A data reading module: used to automatically read dynamic pressure data and steady-state parameter data by means of segmented cyclic reading;

[0028] A data integration module: used to verify the data validity and correct the time axis alignment of the dynamic pressure data and the steady-state data;

[0029] Afterburner data positioning module: Determine the afterburner data position in the dynamic pressure data and steady-state data based on the throttle lever angle being greater than 65°;

[0030] Frequency domain analysis module: Used to perform frequency domain analysis on the afterburner data. The parameters include: sampling rate 51200Hz, sample duration 1 second; FFT step size 0.2 seconds, Butterworth low-pass filter, cut-off frequency 3000Hz; Hanning window function, no average peak mode;

[0031] Frequency domain analysis extraction module: Used to extract the maximum amplitude H, frequency value F, average amplitude H0 of the oscillation mode, continuity evaluation parameter C, and dynamic pressure pulsation peak H max and the maximum pulsation peak data set;

[0032] Input module: Used to input the calculation results into the database file in a specific format.

[0033] The advantages of this application include: This solution designs an intelligent data analysis algorithm, which improves the automation degree of the afterburner oscillating combustion data analysis work. While greatly improving work efficiency, it reduces the manual occupancy rate of oscillating combustion data processing and saves the cost of model development. In addition, the database designed and constructed by the present invention can comprehensively reflect the main characteristics of afterburner oscillating combustion, facilitating the comparison and analysis of front and back data, and improving the comprehensiveness and operability of oscillating combustion data analysis. Brief Description of the Drawings

[0034] Figure 1 It is the main logic flow chart of the method for constructing the aero-engine oscillating combustion characteristic parameter database. Detailed Embodiment

[0035] To make the technical solution and its advantages of this application clearer, the technical solution of this application will be further clearly and completely described in detail below in conjunction with the drawings. It can be understood that the specific embodiments described here are only partial embodiments of this application, which are only used to explain this application and not to limit this application. It should be noted that for the convenience of description, only the parts related to this application are shown in the drawings, and other related parts can refer to the normal design. Without conflict, the embodiments and the technical features in the embodiments of this application can be combined with each other to obtain new embodiments.

[0036] In addition, it should be noted that unless otherwise clearly specified and defined, the similar terms such as "installed", "connected", and "linked" used in the description of this application should be understood in a broad sense. For example, the connection can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can also be the communication inside two components. Those skilled in the art can understand its specific meaning in this application according to the specific situation.

[0037] Contents included in the database:

[0038] Afterburning time (t_jl): The total time of the entire afterburning process, including the process of turning on afterburning, the process of maintaining afterburning, and the process of exiting afterburning;

[0039] Maximum throttle lever angle (Pd max ): The maximum angle of the actual movement of the throttle lever during the entire afterburning process;

[0040] Maximum amplitude (H) and frequency value (F) of the oscillation mode: During the entire afterburning process, within the set frequency bandwidth range of each oscillation mode, the maximum value of the dynamic pressure characteristic frequency amplitude of each oscillation mode captured and its corresponding characteristic frequency value;

[0041] Average amplitude (H0) of the oscillation mode: During the process of maintaining afterburning, the average value of the amplitudes of the characteristic frequency signals corresponding to each oscillation mode;

[0042] Continuity evaluation parameter (C): Used to evaluate the continuity of the characteristic frequency signals corresponding to each oscillation mode during the entire afterburning process;

[0043] Maximum pulsation peak data group: During the entire afterburning process, within the full frequency band range, at the moment when the dynamic pressure characteristic frequency amplitude of the afterburner reaches the maximum, the set of each system parameter and dynamic parameter, including the following parameters:

[0044] Dynamic pressure amplitude (H max ); Dynamic pressure frequency value (F max ); Time (t); Throttle lever angle (Pd); Oil pressure of afterburning circuit 1 (Py1); Oil pressure of afterburning circuit 2 (Py2); Oil pressure of afterburning circuit 3 (Py3); Oil pressure of afterburning circuit 4 (Py4); Nozzle area (Ap).

[0045] Database construction process:

[0046] Algorithm logic

[0047] The main logic of the algorithm for constructing the database of the aero-engine oscillation combustion characteristic parameters designed by the present invention is shown in the following figure.

[0048] Step 1: Data reading. The main function is to automatically read the dynamic pressure data and steady-state parameter data of the same test run. To speed up the calculation and reduce the error rate of the program, the method of segmented loop reading is adopted for reading the dynamic pressure test data;

[0049] Step 2: Data integration. The main functions are to implement the validity check and data alignment of the two types of data. Once special situations such as the dynamic pressure data not changing with the rotational speed or large-scale irregular fluctuations in some test parameters occur, it is determined that the data is invalid, and the calculation returns to the next set of data. In the case of valid data, by comparing the rotational speed data of the two test systems, the relative time difference between the dynamic pressure data and the steady-state data is calculated, and then the time axis of the steady-state data is corrected, ultimately making the time axes of the two sets of data coincide;

[0050] Step 3: Afterburner data positioning. The main function is to locate the time position of each afterburner (from the start of afterburner activation to the end of afterburner deactivation). Based on the throttle lever angle, the data range where Pd > 65° is located as the time range of the entire afterburner. To ensure the data integrity of the frequency domain analysis, 2 s of data is extended before and after this range, and this is used as the complete data segment for the subsequent frequency domain analysis.

[0051] Calculation of t_jl, the total afterburner time. Taking 65° as the standard, the entire continuous data range where the throttle lever angle is greater than 65° is intercepted as the occurrence range of the afterburner, and its time length is t_jl;

[0052] Pd max , Determination of the maximum throttle lever angle. That is, within the entire determined afterburner data range, the maximum value of the engine throttle lever angle is found;

[0053] Step 4: Frequency domain analysis. The main function is to perform frequency domain analysis on the dynamic pressure data during the entire afterburner process. The means used is short-time Fourier calculation, and its basic settings are as follows:

[0054] a) Sampling rate (data points per second): 51200

[0055] b) Sample time length: 1 s

[0056] c) FFT calculation step size: 0.2 s

[0057] d) Data filtering method: Butterworth low-pass filtering

[0058] e) Filter cut-off frequency: 3000 Hz

[0059] f) Window type: Hanning

[0060] g) Peak averaging method: No averaging

[0061] In order to effectively monitor the peak value changes of each oscillation mode, it is necessary to extract the peak value of the characteristic frequency of each mode in real time during the calculation process. Therefore, it is necessary to define the characteristic frequency range of each oscillation mode before the calculation starts, and the default settings are as follows:

[0062] Table 1 Characteristic frequency band ranges corresponding to each oscillation mode

[0063] Starting frequency / Hz Cut-off frequency / Hz Mode 1 200 300 Mode 2 400 500 Mode 3 810 1010 Mode 4 1250 1450

[0064] Step 5: For modes F and H, calculate the maximum amplitude and frequency value of the characteristic frequency of each mode. During the frequency-domain analysis of the entire afterburning process, extract the amplitude and frequency value of the characteristic frequency of each mode in real time, and obtain the maximum amplitude value of the characteristic frequency of each mode and the corresponding frequency value through one-by-one comparison;

[0065] C, calculation of the continuity evaluation parameter. This parameter is used to evaluate the continuity of the characteristic frequency during the entire afterburning process. The closer the C value is to 1, the better the continuity of the characteristic frequency. The calculation formula is as follows:

[0066]

[0067] In the formula, N H represents the number of points where the amplitude of the characteristic frequency of a certain mode is greater than H C ;

[0068] N S represents the total number of points obtained by calculating the amplitude of the characteristic frequency of a certain mode;

[0069] Among them, the calculation formula of H C is as follows:

[0070]

[0071]

[0072] H2 = 5

[0073] H0, calculation of the average amplitude of the oscillation mode. When the throttle lever angle reaches the maximum, that is, Pd = Pd max , calculate the average amplitude of the characteristic frequency of each mode;

[0074] H max and its data set, calculate the peak value of the dynamic pressure pulsation in the full frequency band range of the entire afterburning process, and record the relevant steady-state parameter information at this moment;

[0075] Step 6: Write to the file and add remarks. After the above calculations are completed, write the calculation results into the database file in a certain format, and enter the remarks text according to the requirements.

[0076] When the above steps are completed in sequence, it means that the analysis and recording of the afterburning oscillation combustion characteristic parameters of this test run have been completed, and the analysis of the next test run data can be started or the program can be ended according to the program settings.

[0077] Based on the above process, a database of afterburning oscillation combustion characteristic parameters for an aeroengine is obtained, including: A data reading module: used to automatically read dynamic pressure data and steady-state parameter data by means of segmented loop reading;

[0078] A data integration module: used to verify the data validity and correct the time axis alignment of the dynamic pressure data and the steady-state data;

[0079] An afterburning data positioning module: based on the throttle lever angle being greater than 65°, determine the afterburning data positioning in the dynamic pressure data and the steady-state data;

[0080] A frequency domain analysis module: used to perform frequency domain analysis on the afterburning data, and the parameters include: sampling rate 51200Hz, sample duration 1 second; FFT step 0.2 second, Butterworth low-pass filter, cut-off frequency 3000Hz; Hanning window function, no average peak mode;

[0081] A frequency domain analysis extraction module: used to extract the maximum amplitude H, frequency value F, average amplitude H0 of the oscillation mode, continuity evaluation parameter C and the peak value H of the dynamic pressure pulsation of each oscillation mode max and the maximum pulsation peak data group;

[0082] An input module: used to input the calculation results into the database file in a format.

[0083] Among them, the time axis alignment method for step 2 specifically includes:

[0084] Step S1: Generate discrete time series for the test parameters measured by each system through different sampling methods, and use the test parameters common to each system as the reference parameters for aligning the time axis;

[0085] Step S2: Determine the inflection point sequences of the dynamic pressure data and the steady-state data;

[0086] Step S3: Determine the characteristic time point sequences of the dynamic pressure data and the steady-state data;

[0087] Step S4: Align the dynamic pressure data and the steady-state data one by one with the aligned inflection point sequences and characteristic time point sequences respectively.

[0088] As described above, it is only the specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed in the present application should be covered within the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claimed rights.

Claims

1. A method for constructing a characteristic parameter database of afterburning oscillating combustion of an aeroengine, characterized in that Including: Step 1: Read the dynamic pressure data and steady-state parameter data automatically in a segmented loop; Step 2: Verify the data validity and correct the time-axis alignment of the dynamic pressure data and the steady-state data; Step 3: Determine the afterburner data location in the dynamic pressure data and the steady-state data based on the throttle lever angle being greater than 65°; Step 4: Conduct a frequency-domain analysis on the afterburner data, with parameters including: sampling rate 51200Hz, sample duration 1 second; FFT step size 0.2 seconds, Butterworth low-pass filtering, cut-off frequency 3000Hz; Hanning window function, no average peak mode; Step 5: Extract the maximum amplitude H, frequency value F, average amplitude H0 of each oscillation mode, continuity evaluation parameter C, and peak value H of dynamic pressure pulsation max and the maximum pulsation peak value data set; Step 6: Enter the calculation results into the database file in a specific format.

2. The method for constructing the afterburning oscillation combustion characteristic parameter database of an aero-engine according to claim 1, wherein, The frequency band range of the oscillation mode includes: Mode 1: 200Hz to 300Hz; Mode 2: 400Hz to 500Hz; Mode 3: 810Hz to 1010Hz; Mode 4: 1250Hz to 1450Hz.

3. The method for constructing the afterburning oscillating combustion characteristic parameter database of an aeroengine according to claim 1, characterized in that, The calculation formula for the continuity evaluation parameter C is as follows: Where N H represents the number of points where the amplitude of a certain modal characteristic frequency is greater than H C ; N S represents the total number of points obtained by calculating the modal characteristic frequency amplitude; Among them, H C The calculation formula is as follows: H2＝5。 4. The method for constructing the afterburning oscillation combustion characteristic parameter database of an aeroengine according to claim 1, characterized in that In the said frequency-domain analysis, the characteristic frequency amplitudes within the preset oscillation mode frequency band range are extracted in real time, and the maximum amplitude and the corresponding frequency of each mode are determined by comparison.

5. The method for constructing the afterburning oscillating combustion characteristic parameter database of an aeroengine according to claim 1, characterized in that The maximum pulsation peak data group includes: Dynamic pressure amplitude H max ; Dynamic pressure frequency value F max ; Time t; Throttle lever angle Pd; Afterburner 1-way oil pressure Py1; Afterburner 2-way oil pressure Py2; Afterburner 3-way oil pressure Py3; Afterburner 4-way oil pressure Py4; Nozzle area Ap.

6. The method for constructing the afterburning oscillating combustion characteristic parameter database of an aeroengine according to claim 5, characterized in that, The extraction method of the said maximum pulsation peak data group is: Identify the dynamic pressure amplitude peak moment within the full frequency band range, and synchronously record the throttle lever angle, oil pressure, nozzle area, and time parameters.

7. An afterburning oscillating combustion characteristic parameter database for an aeroengine, characterized in that, Including: Data reading module: Used to read the dynamic pressure data and steady-state parameter data automatically in a segmented loop; Data integration module: Used to verify the data validity and correct the time-axis alignment of the dynamic pressure data and the steady-state data; Afterburner data location module: Determine the afterburner data location in the dynamic pressure data and the steady-state data based on the throttle lever angle being greater than 65°; Frequency-domain analysis module: Used to conduct a frequency-domain analysis on the afterburner data, with parameters including: sampling rate 51200Hz, sample duration 1 second; FFT step size 0.2 seconds, Butterworth low-pass filtering, cut-off frequency 3000Hz; Hanning window function, no average peak mode; Frequency domain analysis extraction module: used to extract the maximum amplitude H, frequency value F, average amplitude H0 of the oscillation mode, continuity evaluation parameter C, and the peak value H of the dynamic pressure pulsation of each oscillation mode max and the maximum pulsation peak value data group; Entry module: Used to enter the calculation results into the database file in a specific format.

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