CN112857730B - Method for analyzing and processing hypersonic pulse pressure test data - Google Patents
Method for analyzing and processing hypersonic pulse pressure test data Download PDFInfo
- Publication number
- CN112857730B CN112857730B CN202011612459.9A CN202011612459A CN112857730B CN 112857730 B CN112857730 B CN 112857730B CN 202011612459 A CN202011612459 A CN 202011612459A CN 112857730 B CN112857730 B CN 112857730B
- Authority
- CN
- China
- Prior art keywords
- pulsating pressure
- hypersonic
- analyzing
- test data
- processing
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
- G01M9/00—Aerodynamic testing; Arrangements in or on wind tunnels
- G01M9/02—Wind tunnels
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
- G01M9/00—Aerodynamic testing; Arrangements in or on wind tunnels
- G01M9/08—Aerodynamic models
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
- Y02T90/00—Enabling technologies or technologies with a potential or indirect contribution to GHG emissions mitigation
Landscapes
- Physics & Mathematics (AREA)
- Fluid Mechanics (AREA)
- General Physics & Mathematics (AREA)
- Aerodynamic Tests, Hydrodynamic Tests, Wind Tunnels, And Water Tanks (AREA)
Abstract
The invention discloses a method for analyzing and processing hypersonic pulse pressure test data, which is used for analyzing and processing the hypersonic pulse pressure test data based on variational modal decomposition, measuring the pulse pressure on the surface of a hypersonic aerospace vehicle model by using a pulse pressure sensor in a conventional hypersonic wind tunnel, accurately calculating and separating all characteristic waves contained in the pulse pressure test data according to the original test data acquired by wind tunnel operation and the variational modal decomposition, and further analyzing the physical phenomena such as the flow structure, the transition mechanism and the like in the boundary layer of the outer surface of the aerospace vehicle under the hypersonic condition in detail. The invention adopts variation modal decomposition, and solves the problems of false signals, frequency and modal superposition and the like in the process of processing complex hypersonic pulsation pressure signals.
Description
Technical Field
The invention belongs to the technical field of hypersonic velocity wind tunnel tests, and particularly relates to a hypersonic velocity pulsating pressure test data analysis processing method.
Background
When the hypersonic aircraft runs in a near space and an atmosphere for a long time at a high speed, the hypersonic aircraft is subjected to the comprehensive action of multiple physical fields such as severe aerodynamic heat and aerodynamic force, the occurrence and development processes of the flow structure and transition of the boundary layer on the outer surface of the hypersonic aircraft seriously affect the aerodynamic performance of the hypersonic aircraft, and even can become a key factor for judging whether the hypersonic aircraft succeeds or not. Therefore, the flow structure and the transition mechanism of the boundary layer are made clear to be a crucial problem, and the pulsating pressure test is an important means for researching the boundary layer; therefore, the accurate processing and analysis of the pulsating pressure data obtained by the pulsating pressure test are the key problems to be solved finally, the accurate physical information of the model boundary layer is obtained by accurately processing the hypersonic pulsating pressure test data, and the technical support is provided for the development of the hypersonic flight vehicle.
The traditional analysis and processing method for the pulsating pressure test data comprises the conventional Fourier transform and the short-time Fourier transform, and the application of Empirical Mode Decomposition (EMD) to process pulsating pressure signals. The general Fourier change can not give the overall and local characteristics of the time domain and the frequency domain of the pulse pressure signal; the resolution of the short-time fourier transform is heavily dependent on the window size problem, and both analysis processes can appear spurious signals and frequencies. Meanwhile, the empirical mode decomposition method which is superior to the two processing methods also has the defects of lack of selection of mathematical theoretical basis and screening criterion and also has the important disadvantage of incapability of solving the problem of mode aliasing, so that the development and introduction of an applicable method for analyzing and processing the pulsating pressure data is urgently needed, and the technical problem to be solved in the field is urgently needed.
Disclosure of Invention
The technical problem of the invention is solved: the method overcomes the defects of the prior art, provides a method for analyzing and processing hypersonic pulse pressure test data, solves the problem that data obtained by the existing method for analyzing and processing hypersonic pulse pressure data cannot completely reflect correct physical structure information of a surface boundary layer of a hypersonic aircraft, provides a proper method for processing huge and complex pulse pressure signals, and ensures that the data obtained by the pulse pressure test in the hypersonic wind tunnel can finally truly reflect the flow structure and transition mechanism of the surface boundary layer of an aircraft model.
In order to solve the technical problem, the invention discloses a method for analyzing and processing hypersonic pulse pressure test data, which comprises the following steps:
according to the hypersonic wind tunnel test, measuring the pulsating pressure voltage signal value y on the surface of the aerospace craft model through a pulsating pressure sensor i ；
According to the calibrated coefficient of the pulsating pressure sensor, combining the measured pulsating pressure voltage signal value y i And calculating to obtain the pulsating pressure value x on the surface of the aerospace craft model i ；
According to the pulsating pressure value x of the surface of the aerospace vehicle model i Obtaining a pulsating pressure time sequence signal f (t);
decomposing the pulsating pressure timing signal f (t) into a finite number of discrete sub-signals; wherein each sub-signal is an eigenmode function u k (t)；
For intrinsic mode function u k (t) carrying out variational modal decomposition, and resolving to obtain the energy spectrum distribution of the surface pulsating pressure of the aerospace craft model in a frequency domain;
and analyzing the nature of the physical structure of the gas flow on the surface of the aerospace craft model according to the energy spectrum distribution of the surface pulsating pressure of the aerospace craft model on a frequency domain.
In the method for analyzing and processing the hypersonic velocity pulsating pressure test data, the essence of the physical structure of the surface gas flow of the aerospace craft model comprises the following steps: a surface boundary layer flow structure and a transition mechanism of the aerospace craft model.
In the method for analyzing and processing data of the hypersonic velocity pulsating pressure test, the pulsating pressure sensor used in the hypersonic velocity wind tunnel test comprises the following steps: a high-frequency-response PCB sensor and a low-frequency-response Kulite sensor; wherein, the measurable frequency response range of the high-frequency response PCB sensor is 11 KMz-1MHz, and the measurable frequency response range of the Kulite sensor is 0-50 KHz; obtaining the pulsating pressure voltage signal value y in the whole frequency domain range of 0 KHz-1 MHz through a high-frequency-response PCB sensor and a lower-frequency-response Kulite sensor i 。
In the method for analyzing and processing the hypersonic velocity pulsating pressure test data, the pulsating pressure value x on the surface of the aerospace craft model i Is composed of
x i ＝ay i +b···(1)
Wherein, a represents the sensitivity coefficient calibrated by the pulse pressure sensor, and b represents the local standard atmospheric pressure value.
In the method for analyzing and processing the hypersonic velocity pulsating pressure test data, the pulsating pressure value x on the surface of the aerospace craft model is used i Obtaining a pulsating pressure time sequence signal f (t), comprising:
resolving a series of pulse pressure time sequence signals f (x) through a formula (2) i )：
Wherein the content of the first and second substances,
i =1,2, \8230;, n, n represents n consecutive sample values in the pulsating pressure timing signal.
And (3) resolving by adopting a formula (2) to obtain each pulsating pressure time sequence signal to obtain a pulsating pressure time sequence signal f (t).
In the method for analyzing and processing data of hypersonic velocity pulse pressure test, decomposing a pulse pressure time sequence signal f (t) into a finite number of discrete sub-signals comprises:
decomposing the pulsating pressure time sequence signal f (t) into K intrinsic mode functions u k (t)：
Wherein u is k (t) the number of extreme points is equal to the number of zero-crossing points, or the number of extreme points is at most one more than the number of zero-crossing points.
In the method for analyzing and processing the data of the hypersonic velocity pulsation pressure test, the intrinsic mode function u is subjected to k Carrying out variation modal decomposition, and resolving to obtain the energy spectrum distribution of the surface pulsating pressure of the aerospace craft model on a frequency domain, wherein the energy spectrum distribution comprises the following steps:
for intrinsic mode function u k (t) performing a metamorphic modal decomposition to obtain each eigenmode function u k (t) the estimated bandwidth is minimal;
simplifying the calculation of the energy spectrum distribution of the surface pulsating pressure of the aerospace craft model on a frequency domain into the calculation of a minimum nonlinear optimization function with constraint;
and obtaining the energy spectrum distribution of the surface pulsating pressure of the aerospace craft model on a frequency domain according to a solving result of a minimum nonlinear optimization function with constraint.
In the method for analyzing and processing the data of the hypersonic velocity pulsation pressure test, the solving process of a minimum nonlinear optimization function with constraint is as follows:
defining an objective function:
wherein the content of the first and second substances,
is u k Corresponding center frequency, { u } k }＝{u 1 ,u 2 ,…,u K }，
Is u k A corresponding bandwidth;
is u k Corresponding analysis function a k (t)，a k (t)＝u k (t)+iHu k (t), the fourier transform is a single-sided spectrum with only positive frequencies; δ (t) represents a unit pulse function, a k (t) is u k (t) an analytical function of (t),h denotes the Hilbert transform, t denotes the time series, j denotes the imaginary unit, j denotes the time series 2 ＝-1；
Determining enhanced operators
Wherein, lambda represents Lagrange multiplication operator, a represents secondary punishment parameter, and < · > represents inner product operation;
equation (4) is solved according to equation (5).
The invention has the following advantages:
(1) Compared with the traditional pulse pressure data analysis processing method, the method solves the problems that the overall appearance and the local characteristics of a pulse pressure signal time domain and a pulse pressure signal frequency domain cannot be given, and the resolution of the method depends on the selected window function seriously.
(2) The invention adopts variational modal decomposition, thus solving the problems of false signals, frequency and modal superposition and the like in the process of processing complex hypersonic pulsating pressure signals; compared with the traditional pulse pressure data analysis and processing method, the method can avoid introducing false signals and frequencies and noise information.
(3) The method has sufficient mathematical theory support, particularly solves the problem of mode aliasing compared with an EMD method, can clearly separate various waveforms contained in signals and obtain a real frequency spectrum.
(4) The method is not only suitable for analyzing and processing the hypersonic pulse pressure test data, but also suitable for analyzing and processing the pulse pressure test data of the sub-transonic wind tunnel.
Drawings
FIG. 1 is a flow chart illustrating steps of a method for analyzing and processing hypersonic pulse pressure test data according to an embodiment of the present invention;
FIG. 2 is a schematic diagram of a prediction result of processing data of a hypersonic aircraft model pulsating pressure test in the embodiment of the invention;
FIG. 3 is a schematic diagram of a prediction result of processing data of a pulse pressure test of a hypersonic aircraft model in an embodiment of the invention.
Detailed Description
To make the objects, technical solutions and advantages of the present invention more apparent, the embodiments of the present invention will be described in detail with reference to the accompanying drawings.
As shown in fig. 1, in this embodiment, the method for analyzing and processing hypersonic pulse pressure test data is characterized by including:
step 1, measuring a pulsating pressure voltage signal value y on the surface of the aerospace craft model through a pulsating pressure sensor according to a hypersonic wind tunnel test i 。
In the present embodiment, the pulsating pressure sensor used in the hypersonic wind tunnel test includes, but is not limited to: a high frequency response PCB sensor and a low frequency response kulite sensor. Wherein, the measurable frequency response range of the high-frequency response PCB sensor is 11 KMz-1MHz, the measurable frequency response range of the Kulite sensor is 0-50 KHz, namely, the pulsating pressure voltage signal value y in the whole frequency domain range of 0 KHz-1 MHz can be obtained through the high-frequency response PCB sensor and the lower-frequency response Kulite sensor i 。
Step 2, combining the measured pulsating pressure voltage signal value y according to the coefficient calibrated by the pulsating pressure sensor i And calculating to obtain the pulsating pressure value x on the surface of the aerospace craft model i 。
In the embodiment, the pulsating pressure value x of the surface of the aerospace vehicle model i Can be expressed as follows:
x i ＝ay i +b···(1)
wherein, a represents the sensitivity coefficient calibrated by the pulse pressure sensor, and b represents the local standard atmospheric pressure value.
Step 3, according to the pulsation pressure value x of the surface of the aerospace craft model i And obtaining a pulsating pressure time sequence signal f (t).
In the present embodiment, it can be solved by the following formula (2)Calculating to obtain a series of pulse pressure time sequence signals f (x) i )：
Wherein, the first and the second end of the pipe are connected with each other,
i =1,2, \8230;, n, n represents n consecutive sample values in the pulsating pressure timing signal.
And (3) respectively resolving by adopting a formula (2) to obtain each pulsating pressure time sequence signal, and further obtaining a pulsating pressure time sequence signal f (t).
And 4, decomposing the pulsating pressure time sequence signal f (t) into a finite number of discrete sub-signals.
In this embodiment, a complex pulsating pressure timing signal is decomposed into a finite number of discrete sub-signals, each sub-signal being an Intrinsic Mode Function (IMF) u k (t), the linear superposition of all eigenmodes can fully recover the pulsating pressure timing signal.
Preferably, the pulsating pressure time-series signal f (t) is decomposed into K eigenmode functions u k (t)：
Wherein u is k (t) the number of extreme points is equal to the number of zero-crossing points, or the number of extreme points is at most one more than the number of zero-crossing points.
Step 5, for the intrinsic mode function u k And (t) carrying out variation modal decomposition, and resolving to obtain the energy spectrum distribution of the surface pulsating pressure of the aerospace craft model in the frequency domain.
In this embodiment, according to a Variation Mode Decomposition (VMD) algorithm, eigenmodes of each order are sufficiently separated in scale, and the processing of pulse pressure test data is completed by obtaining the energy spectrum distribution of the surface pulse pressure of the hypersonic aerospace vehicle model in the frequency domain. In particular toThe process can be as follows: for intrinsic mode function u k (t) performing a metamorphic modal decomposition to obtain each eigenmode function u k (t) the estimated bandwidth is minimal; simplifying the calculation of the energy spectrum distribution of the surface pulsating pressure of the aerospace craft model on a frequency domain into the calculation of a minimum nonlinear optimization function with constraint; and obtaining the energy spectrum distribution of the surface pulsating pressure of the aerospace craft model on a frequency domain according to a solving result of a minimum nonlinear optimization function with constraints.
Preferably, the solving process for a constrained minimum nonlinear optimization function is as follows:
defining an objective function:
wherein the content of the first and second substances,
is u k Corresponding center frequency, { u { k }＝{u 1 ,u 2 ,…,u K }，
Is u k A corresponding bandwidth;
is u k Corresponding analysis function a k (t)，a k (t)＝u k (t)+iHu k (t) its fourier transform is a single-sided spectrum with only positive frequencies; δ (t) represents a unit pulse function, a k (t) is u k (t) analysis function, H represents Hilbert transform, t represents time series, j represents imaginary unit, j 2 ＝-1。
Determining enhanced operators
Wherein, lambda represents Lagrange multiplier, a represents secondary punishment parameter, and < > represents inner product operation.
And (4) solving the formula (4) according to the formula (5) to obtain a solving result of the minimum nonlinear optimization function with the constraint, and finishing the processing of the pulsating pressure data.
And 6, analyzing the nature of the physical structure of the gas flow on the surface of the aerospace craft model according to the energy spectrum distribution of the surface pulsating pressure of the aerospace craft model on the frequency domain.
In this embodiment, analyzing the physical structure nature of the surface gas flow of the aerospace vehicle model may specifically be to analyze a surface boundary layer flow structure and a transition mechanism of the aerospace vehicle model.
In conclusion, the pulsation pressure of the surface of the hypersonic spacecraft model is measured by a pulsation pressure sensor in a conventional hypersonic wind tunnel, all characteristic waves contained in the pulsation pressure test data are accurately calculated and separated through variational modal decomposition according to the original test data acquired by wind tunnel operation, and the physical phenomena such as the flow structure and transition mechanism in the boundary layer of the outer surface of the hypersonic spacecraft under the hypersonic condition are further analyzed in detail. The invention adopts variation modal decomposition, and solves the problems of false signals, frequency and modal superposition and the like in the process of processing complex hypersonic pulsation pressure signals.
As can be seen from fig. 2 and 3, by using the method for analyzing and processing hypersonic pulse pressure test data, signals with different frequencies and amplitudes contained in pulse pressure signals can be clearly decomposed, and the problems of mode aliasing and the like caused by false signals and noise are effectively solved; for example, various characteristic waves included in the pulsating pressure signal, such as whether the characteristic waves are first mode waves, second mode waves, vortex waves or the like, can be clearly obtained, and then the flow structure and transition mechanism of the surface boundary layer of the aircraft model are analyzed accordingly.
Although the present invention has been described with reference to the preferred embodiments, it is not intended to limit the present invention, and those skilled in the art can make variations and modifications of the present invention without departing from the spirit and scope of the present invention by using the methods and technical contents disclosed above.
Those skilled in the art will appreciate that the invention may be practiced without these specific details.
Claims (6)
1. A method for analyzing and processing hypersonic pulse pressure test data is characterized by comprising the following steps:
according to the hypersonic wind tunnel test, measuring the pulsating pressure voltage signal value y on the surface of the aerospace craft model through a pulsating pressure sensor i ；
According to the calibrated coefficient of the pulsating pressure sensor, combining the measured pulsating pressure voltage signal value y i And calculating to obtain the pulsating pressure value x on the surface of the aerospace craft model i ；
According to the pulsating pressure value x on the surface of the aerospace vehicle model i Obtaining a pulsating pressure time sequence signal f (t);
decomposing the pulsating pressure timing signal f (t) into a finite number of discrete sub-signals; wherein each sub-signal is an eigenmode function u k (t)；
For intrinsic mode function u k (t) carrying out variation modal decomposition, and resolving to obtain the energy spectrum distribution of the surface pulsating pressure of the aerospace craft model in a frequency domain;
analyzing the nature of a physical structure of the gas flow on the surface of the aerospace craft model according to the energy spectrum distribution of the surface pulsating pressure of the aerospace craft model in a frequency domain;
wherein:
space flightPulsating pressure value x of aircraft model surface i Comprises the following steps:
x i ＝ay i +b···(1)
wherein, a represents the sensitivity coefficient calibrated by the pulsating pressure sensor, and b represents the local standard atmospheric pressure value;
according to the pulsating pressure value x on the surface of the aerospace vehicle model i Obtaining a pulsating pressure time sequence signal f (t), comprising:
resolving a series of pulse pressure time sequence signals f (x) through a formula (2) i )：
Wherein the content of the first and second substances,
i =1,2, \8230, n, n represents n consecutive sample values in the pulsating pressure timing signal;
and (3) resolving by adopting a formula (2) to obtain each pulsating pressure time sequence signal to obtain a pulsating pressure time sequence signal f (t).
2. The method for analyzing and processing the hypersonic pulse pressure test data according to claim 1, wherein the nature of the physical structure of the gas flow on the surface of the model of the aerospace vehicle comprises: the surface boundary layer flow structure and transition mechanism of the aerospace craft model.
3. The method for analyzing and processing hypersonic pulse pressure test data according to claim 1, wherein in the hypersonic wind tunnel test, the pulse pressure sensor used comprises: a high-frequency-response PCB sensor and a low-frequency-response Kulite sensor; wherein, the measurable frequency response range of the high-frequency response PCB sensor is 11 kHz-1MHz, and the measurable frequency response range of the Kulite sensor is 0-50 kHz; the pulsating pressure voltage signal value y in the whole frequency domain range of 0 kHz-1 MHz is obtained through a high-frequency-response PCB sensor and a low-frequency-response Kulite sensor i 。
4. The method for analyzing and processing hypersonic pulse pressure test data as claimed in claim 1, wherein decomposing the pulse pressure time series signal f (t) into a finite number of discrete sub-signals comprises:
decomposing the pulse pressure time sequence signal f (t) into K intrinsic mode functions u k (t)：
Wherein u is k (t) the number of extreme points is equal to the number of zero-crossing points, or the number of extreme points is at most one more than the number of zero-crossing points.
5. The method for analyzing and processing hypersonic pulse pressure test data according to claim 4, wherein the intrinsic mode function u is processed k (t) carrying out variation modal decomposition, and resolving to obtain the energy spectrum distribution of the surface pulsating pressure of the aerospace craft model on a frequency domain, wherein the energy spectrum distribution comprises the following steps:
for intrinsic mode function u k (t) performing a metamorphic modal decomposition to obtain each eigenmode function u k (t) the estimated bandwidth is minimal;
simplifying the calculation of the energy spectrum distribution of the surface pulsating pressure of the aerospace craft model on a frequency domain into the calculation of a minimum nonlinear optimization function with constraint;
and obtaining the energy spectrum distribution of the surface pulsating pressure of the aerospace craft model on a frequency domain according to a solving result of a minimum nonlinear optimization function with constraint.
6. The method for analyzing and processing hypersonic pulse pressure test data according to claim 5, wherein the solving process of a minimum nonlinear optimization function with constraints is as follows:
defining an objective function:
wherein, the first and the second end of the pipe are connected with each other,
is u k Corresponding center frequency, { u { k }＝{u 1 ,u 2 ,…,u K }，
Is u k A corresponding bandwidth;
is u k A corresponding analysis function; delta (t) represents a unit pulse function, t represents a time series, j represents an imaginary unit, j represents a unit of an imaginary number 2 ＝-1；
Determining enhanced operators
Wherein, lambda represents Lagrange multiplication operator, a represents secondary punishment parameter, and < > represents inner product operation;
equation (4) is solved according to equation (5).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011612459.9A CN112857730B (en) | 2020-12-30 | 2020-12-30 | Method for analyzing and processing hypersonic pulse pressure test data |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011612459.9A CN112857730B (en) | 2020-12-30 | 2020-12-30 | Method for analyzing and processing hypersonic pulse pressure test data |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN112857730A CN112857730A (en) | 2021-05-28 |
| CN112857730B true CN112857730B (en) | 2023-02-03 |
Family
ID=75998563
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202011612459.9A Active CN112857730B (en) | 2020-12-30 | 2020-12-30 | Method for analyzing and processing hypersonic pulse pressure test data |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112857730B (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113494990B (en) * | 2021-06-28 | 2024-05-03 | 中国航天空气动力技术研究院 | Analysis method for influence of wind tunnel disturbance on thickness of supersonic laminar boundary layer |
| CN114060357B (en) * | 2021-10-20 | 2023-11-07 | 南京航空航天大学 | Hypersonic boundary layer transition control device and hypersonic boundary layer transition control method based on ultrasonic waves |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2003065891A (en) * | 2001-08-24 | 2003-03-05 | National Aerospace Laboratory Of Japan | Pressure fluctuation reducing method in air course and its device in circular stream type supersonic wind tunnel |
| CN107843406A (en) * | 2017-10-31 | 2018-03-27 | 中国空气动力研究与发展中心高速空气动力研究所 | Cavity mode wave motion feature based on fluctuation pressure correlation function determines method |
| CN109977920A (en) * | 2019-04-11 | 2019-07-05 | 福州大学 | Fault Diagnosis of Hydro-generator Set method based on time-frequency spectrum and convolutional neural networks |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5983162A (en) * | 1996-08-12 | 1999-11-09 | The United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration | Computer implemented empirical mode decomposition method, apparatus and article of manufacture |
| CN107832534A (en) * | 2017-11-16 | 2018-03-23 | 中国航天空气动力技术研究院 | For the frequency low-amplitude value signal recognition methods of Pulse Pressure with High Frequency test system |
| CN109813230A (en) * | 2019-01-09 | 2019-05-28 | 上海电力学院 | A kind of optical grating Moire fringe denoising method based on VMD |
| CN110455490B (en) * | 2019-08-21 | 2020-11-17 | 中国人民解放军国防科技大学 | Method and device for calculating supersonic velocity and hypersonic velocity wind tunnel flow field turbulence |
-
2020
- 2020-12-30 CN CN202011612459.9A patent/CN112857730B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2003065891A (en) * | 2001-08-24 | 2003-03-05 | National Aerospace Laboratory Of Japan | Pressure fluctuation reducing method in air course and its device in circular stream type supersonic wind tunnel |
| CN107843406A (en) * | 2017-10-31 | 2018-03-27 | 中国空气动力研究与发展中心高速空气动力研究所 | Cavity mode wave motion feature based on fluctuation pressure correlation function determines method |
| CN109977920A (en) * | 2019-04-11 | 2019-07-05 | 福州大学 | Fault Diagnosis of Hydro-generator Set method based on time-frequency spectrum and convolutional neural networks |
Non-Patent Citations (3)
| Title |
|---|
| 基于VMD和排列熵的水轮机压力脉动信号去噪算法;于晓东等;《水力发电学报》;20170825;第36卷(第08期);第79-74页 * |
| 高超声内外流中若干典型脉动压力问题;黄蓉;《中国优秀博硕士学位论文全文数据库（博士）基础科学辑》;20190815(第8期);全文 * |
| 高超声速条件下7°直圆锥边界层转捩实验研究;刘小林等;《物理学报》;20180814;第67卷(第17期);第174701-2~174701-4页 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN112857730A (en) | 2021-05-28 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN110455490B (en) | Method and device for calculating supersonic velocity and hypersonic velocity wind tunnel flow field turbulence | |
| CN109682561B (en) | Method for automatically detecting free vibration response of high-speed railway bridge to identify mode | |
| CN112857730B (en) | Method for analyzing and processing hypersonic pulse pressure test data | |
| Kegerise et al. | Mode-switching and nonlinear effects in compressible flow over a cavity | |
| CN110333285B (en) | Ultrasonic lamb wave defect signal identification method based on variational modal decomposition | |
| CN102636568B (en) | Finite element ultrasonic imaging method used for detecting defect in concrete | |
| CN111553877B (en) | Damage identification and service life evaluation method based on terahertz ceramic matrix composite blade | |
| CN110596247B (en) | Ultrasonic structure health monitoring method in temperature change environment | |
| CN104020135A (en) | Calibration model establishing method based on near infrared spectrum | |
| CN109870282A (en) | Compressed sensing based blade vibration feature identification method and system | |
| US11768180B1 (en) | Method for ultrasonic guided wave quantitative imaging in form of variable array | |
| Hua et al. | Modified minimum variance imaging of Lamb waves for damage localization in aluminum plates and composite laminates | |
| CN110057918B (en) | Method and system for quantitatively identifying damage of composite material under strong noise background | |
| CN111751070A (en) | Tuned liquid damper performance parameter detection method, system, device and medium | |
| CN114137616B (en) | Method for detecting gas content of reservoir by utilizing quantum mechanics principle | |
| CN105352726A (en) | Fault diagnosis method for gear | |
| CN115718860A (en) | Low-frequency oscillation mode identification method based on mode decomposition and sparse time domain method | |
| CN111427046B (en) | Terahertz pulse echo positioning method for improving detection precision | |
| CN113237951A (en) | Metal plate fatigue damage ultrasonic guided wave detection method based on shape context dynamic time warping | |
| US20240003855A1 (en) | Method for extracting feature path signals of pipeline ultrasonic helical guided waves | |
| CN112131781A (en) | Steel structure damage detection method based on full-connection neural network and transfer rate function | |
| Wu et al. | Statistical significance test of intrinsic mode functions | |
| CN114061848B (en) | Method for identifying leak hole of reinforced sealing structure of spacecraft | |
| CN113156278A (en) | CNN network-based GIS partial discharge positioning method | |
| Zhang et al. | Study on the relationship between bolt anchoring defects and complexity of nondestructive testing signal |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |