Carrier rocket pulsating pressure test data processing method and system

Abstract

The invention relates to a carrier rocket pulsating pressure test data processing method and system, and belongs to the field of carrier rocket pneumatic design. The method comprises the steps of calculating a pressure coefficient, calculating a trend term of the pressure coefficient, calculating a trend term-removed pressure coefficient, calculating power spectral density, identifying non-physical frequency components, eliminating the non-physical frequency components and calculating a root mean square pulsating pressure coefficient. According to the carrier rocket pulsating pressure test data processing method, non-physical pulsating components in the flight process of the carrier rocket can be stripped, the pulsating pressure coefficient used for load design is effectively reduced, the pulsating pressure coefficient can be reduced by more than 20%, and the fine design requirement of the aerodynamic load of the carrier rocket is met.

Description

Technical Field

[0001] The invention relates to a carrier rocket pulsation pressure test data processing method and system, belonging to the field of carrier rocket aerodynamic design. Background Art

[0002] When the rocket passes through the atmosphere, it experiences subsonic, transonic and supersonic flows. In the parts where the cross-section changes sharply, such as the cone-column shoulder, the hammerhead contraction section, and the front of the skirt-column, unsteady flow phenomena such as shock wave-boundary layer interference, shock wave oscillation, detached flow separation, and attached turbulent pulsation occur, which produce unsteady pressure pulsations with strong nonlinear characteristics. Unsteady pulsating pressure is one of the main causes of rocket elastic loads and the dynamic environment of rockets and satellites, affecting the rocket body load, vibration and noise environment, and stimulating the rocket bending mode. It is an important input parameter for the design of load strength, dynamic characteristics, rocket body structure, and elastic stability.

[0003] At present, the main means of obtaining pulsating pressure is to conduct wind tunnel tests on scaled models. In the test, a pulsating sensor is used to measure the time domain signal of the surface pressure of the wind tunnel model, and then the pulsating pressure coefficient required for rocket load design is obtained through data processing methods. The pulsating pressure sensor is small in size and highly sensitive. It uses the piezoelectric effect of piezoelectric crystals to convert the pressure applied to its surface into an electric charge to achieve pressure measurement. In the pulsating pressure wind tunnel test, it is affected by a variety of interference factors, such as: the inherent deviation of the wind tunnel compressor in a specific Ma range, the influence of the inherent frequency of the turbofan drive, etc., which may cause flow phenomena (Comparison of Ares I-X Wind-Tunnel Derived Buffet Environment with Flight Data) or unsteady pressure source items on the surface of the scaled model that do not exist in the rocket flight, so that the pulsating pressure coefficient obtained based on the wind tunnel test results cannot meet the requirements of the refined design of the launch vehicle's aerodynamic load. Therefore, a data processing method for wind tunnel pulsating pressure tests is needed. Summary of the invention

[0004] The purpose of the present invention is to overcome the above-mentioned deficiencies in the prior art and to provide a method and system for processing launch vehicle pulsation pressure test data, which can remove the non-physical pulsation components during the flight of the launch vehicle and effectively reduce the pulsation pressure coefficient used in the load design.

[0005] The above-mentioned purpose of the present invention is mainly achieved through the following technical solutions:

[0006] A launch vehicle pulsation pressure test data processing method, comprising:

[0007] Obtain the original pressure of the wind tunnel test, calculate the time domain data of the pressure coefficient based on the wind tunnel dynamic pressure and the reference pressure, and draw a curve of the time domain data of the pressure coefficient changing with time;

[0008] Smoothing the time domain data of the pressure coefficient to obtain pressure coefficient trend item data;

[0009] Subtract the pressure coefficient trend item data from the time domain data of the pressure coefficient to obtain the pressure coefficient data without trend item;

[0010] According to the detrended item pressure coefficient data, the power spectrum density of the detrended item pressure coefficient is calculated, and a curve of the power spectrum density changing with the circular frequency is plotted;

[0011] Using the curve of power spectrum density changing with circular frequency, the non-physical frequency components in power spectrum density can be identified;

[0012] Designing a band-stop filter for the non-physical frequency components, processing the detrended pressure coefficient data, and obtaining the detrended pressure time domain data with the non-physical frequency components removed;

[0013] The root mean square pulsation pressure coefficient is calculated based on the detrended term and the pressure time domain data with non-physical frequency components removed.

[0014] In the above-mentioned launch vehicle pulsation pressure test data processing method, the original pressure of the wind tunnel test is obtained, and then the time domain data of the pressure coefficient is calculated according to the wind tunnel dynamic pressure and the reference pressure, and the time domain data of the pressure coefficient is plotted over time, including:

[0015]

[0016] in, is the time domain data of the pressure coefficient, is the original pressure, q is the wind tunnel dynamic pressure, P 0 is the reference pressure and t is the time.

[0017] In the above-mentioned carrier rocket pulsation pressure test data processing method, the time domain data of the pressure coefficient is smoothed by a multi-point smoothing method to obtain the pressure coefficient trend item data, including:

[0018]

[0019] in, is the pressure coefficient trend item data, is the time domain data of the pressure coefficient, and t is the time.

[0020] In the above-mentioned carrier rocket pulsation pressure test data processing method, the pressure coefficient trend item data is subtracted from the time domain data of the pressure coefficient to obtain the detrended pressure coefficient data, including:

[0021]

[0022] in, is the detrended pressure coefficient data.

[0023] In the above-mentioned launch vehicle pulsation pressure test data processing method, the power spectrum density of the detrended item pressure coefficient is calculated according to the detrended item pressure coefficient data, including:

[0024]

[0025] Where PSD is the power spectral density, is the detrended pressure coefficient data, T is the sampling signal duration, t is the time, and ω is the circular frequency.

[0026] In the above-mentioned carrier rocket pulsation pressure test data processing method, a band-stop filter is designed for the non-physical frequency components, and the detrended pressure coefficient data is processed to obtain the detrended pressure time domain data and the pressure time domain data with the non-physical frequency components removed.

[0027]

[0028] Among them, C p (t) is the pressure time domain data with trend removed and non-physical frequency components removed, is the detrended pressure coefficient data.

[0029] In the above-mentioned carrier rocket pulsation pressure test data processing method, the root mean square pulsation pressure coefficient is calculated according to the pressure time domain data with the detrended term and non-physical frequency components removed, including:

[0030]

[0031] in, is the root mean square pulsation pressure coefficient, T is the sampling signal duration, t is time, C p (t) is the pressure time domain data after removing the trend term and non-physical frequency components.

[0032] A launch vehicle pulsation pressure test data processing system, comprising:

[0033] The first calculation module obtains the original pressure of the wind tunnel test, calculates the time domain data of the pressure coefficient according to the wind tunnel dynamic pressure and the reference pressure, and plots the change curve of the time domain data of the pressure coefficient over time;

[0034] A first processing module performs smoothing processing on the time domain data of the pressure coefficient to obtain pressure coefficient trend item data;

[0035] A second calculation module, subtracting the pressure coefficient trend item data from the time domain data of the pressure coefficient to obtain the detrended pressure coefficient data;

[0036] A third calculation module calculates the power spectrum density of the detrended item pressure coefficient according to the detrended item pressure coefficient data, and plots a curve of the power spectrum density versus the circular frequency;

[0037] The recognition module uses the curve of power spectrum density changing with circular frequency to identify the non-physical frequency components in the power spectrum density;

[0038] The second processing module designs a band-stop filter for the non-physical frequency components, processes the detrended pressure coefficient data, and obtains the pressure time domain data with detrended items and non-physical frequency components removed;

[0039] The fourth calculation module calculates the root mean square pulsation pressure coefficient according to the detrended item and the pressure time domain data with non-physical frequency components removed.

[0040] A computer device comprises a memory, a processor and a computer program stored in the memory, wherein the processor executes the computer program to implement the steps of the above method.

[0041] A computer program product comprises a computer program, which implements the steps of the above method when executed by a processor.

[0042] Compared with the prior art, the present invention has at least the following beneficial effects:

[0043] (1) The carrier rocket pulsation pressure test data processing method provided by the present invention can remove the non-physical pulsation components during the flight of the carrier rocket and effectively reduce the pulsation pressure coefficient used in the load design.

[0044] (2) The launch vehicle pulsation pressure test data processing method provided by the present invention can obtain a more accurate pulsation pressure coefficient, reduce the pulsation pressure coefficient by more than 20%, and meet the requirements of the refined design of the launch vehicle aerodynamic load. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 This is a flow chart of a method for processing data of a launch vehicle pulsation pressure test in an embodiment of the present invention;

[0046] Figure 2 The original pulsating pressure coefficient and trend item diagram in the embodiment of the present invention;

[0047] Figure 3is the detrended term and the non-physical fairing root mean square pulsation pressure coefficient in the embodiment of the present invention. DETAILED DESCRIPTION

[0048] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments:

[0049] like Figure 1 As shown, the carrier rocket pulsation pressure test data processing method of the present invention comprises the following steps:

[0050] Step 1: Obtain the original pressure of the wind tunnel test According to the wind tunnel dynamic pressure q, reference pressure P 0 Time Domain Data for Calculating Pressure Coefficients And draw the curve of the time domain data of the pressure coefficient changing with time. The specific formula is as follows:

[0051]

[0052] Step 2: Use the multi-point smoothing method to process the pressure coefficient and obtain the pressure coefficient trend item data. The formula is as follows:

[0053]

[0054] in, is the pressure coefficient trend item data, is the time domain data of the pressure coefficient, and t is the time.

[0055] Step 3: Subtract the pressure coefficient trend data from the time domain data of the pressure coefficient to obtain the detrended pressure coefficient data.

[0056]

[0057] in, is the detrended pressure coefficient data.

[0058] Step 4: Calculate the power spectrum density of the detrended pressure coefficient using the following formula based on the detrended pressure coefficient data, and plot the power spectrum density versus circular frequency curve.

[0059]

[0060] Where PSD is the power spectral density, is the detrended pressure coefficient data, T is the sampling signal duration, t is the time, and ω is the circular frequency.

[0061] Step 5: Use the curve of power spectrum density changing with circular frequency to identify the non-physical frequency (ω np1 ,ω np2 ,ω np3,...) components, and specific methods include but are not limited to:

[0062] (1) Analyze historical wind tunnel test results and identify frequencies caused by the test method. For example, high energy frequencies that only appear in the test results of a specific wind tunnel are identified as non-physical frequency components.

[0063] (2) Analyze the flight test results and identify frequencies that do not exist during flight. For example, compare the flight test results with the wind tunnel measurement results. If the frequencies do not exist in the flight test results but exist in the wind tunnel measurement results, identify them as non-physical frequency components.

[0064] Step 6: Design a band-stop filter for non-physical frequency components, process the detrended pressure coefficient data, and obtain the pressure time domain data with detrended items and non-physical frequency components removed. The formula is as follows:

[0065]

[0066] Among them, C p (t) is the pressure time domain data after removing the trend term and non-physical frequency components.

[0067] Step 7: Calculate the root mean square pulsation pressure coefficient based on the detrended term and the pressure time domain data with non-physical frequency components removed. The formula is as follows:

[0068]

[0069] in, is the root mean square pulsation pressure coefficient, T is the sampling signal duration, t is the time,

[0070] The present invention also provides a launch vehicle pulsation pressure test data processing system, comprising:

[0071] The first calculation module obtains the original pressure of the wind tunnel test, calculates the time domain data of the pressure coefficient according to the wind tunnel dynamic pressure and the reference pressure, and plots the change curve of the time domain data of the pressure coefficient over time;

[0072] A first processing module performs smoothing processing on the time domain data of the pressure coefficient to obtain pressure coefficient trend item data;

[0073] A second calculation module, subtracting the pressure coefficient trend item data from the time domain data of the pressure coefficient to obtain the detrended pressure coefficient data;

[0074] A third calculation module calculates the power spectrum density of the detrended item pressure coefficient according to the detrended item pressure coefficient data, and plots a curve of the power spectrum density versus the circular frequency;

[0075] The recognition module uses the curve of power spectrum density changing with circular frequency to identify the non-physical frequency components in the power spectrum density;

[0076] The second processing module designs a band-stop filter for the non-physical frequency components, processes the detrended pressure coefficient data, and obtains the pressure time domain data with detrended items and non-physical frequency components removed;

[0077] The fourth calculation module calculates the root mean square pulsation pressure coefficient according to the detrended item and the pressure time domain data with non-physical frequency components removed.

[0078] The present invention also provides a computer device, comprising a memory, a processor and a computer program stored in the memory, wherein the processor executes the computer program to implement the steps of the above method.

[0079] The present invention also provides a computer program product, comprising a computer program, which implements the steps of the above method when executed by a processor.

[0080] By using the present invention to process the pulsation pressure test data of a carrier rocket, the pulsation pressure coefficient can be reduced by more than 20%.

[0081] Example

[0082] like Figure 2 Shown is a graph of the original pulsating pressure coefficient and trend item in an embodiment of the present invention; Figure 3 The detrended term and the non-physical fairing root mean square pulsation pressure coefficient in the embodiment of the present invention are shown. The original pressure coefficient and the pressure coefficient trend term in this embodiment are shown in FIG. Figure 2 , the directly calculated pulsation pressure coefficient is 9.1%. The pressure coefficient of the detrended term and non-physical frequency component is shown in Figure 3 The root mean square pulsation pressure calculated by the method of the present invention is 6.8%, which is reduced by 25%.

[0083] The above description is only the best specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

[0084] The contents not described in detail in the specification of the present invention belong to the common knowledge of the professionals in this field.

Claims

1. A method for processing data of a launch vehicle pulsation pressure test, characterized in that: include: Obtain the original pressure of the wind tunnel test, calculate the time domain data of the pressure coefficient based on the wind tunnel dynamic pressure and the reference pressure, and draw a curve of the time domain data of the pressure coefficient changing with time; Smoothing the time domain data of the pressure coefficient to obtain pressure coefficient trend item data; Subtract the pressure coefficient trend item data from the time domain data of the pressure coefficient to obtain the pressure coefficient data without trend item; According to the detrended item pressure coefficient data, the power spectrum density of the detrended item pressure coefficient is calculated, and a curve of the power spectrum density changing with the circular frequency is plotted; Using the curve of power spectrum density changing with circular frequency, the non-physical frequency components in power spectrum density can be identified; Designing a band-stop filter for the non-physical frequency components, processing the detrended pressure coefficient data, and obtaining the detrended pressure time domain data with the non-physical frequency components removed; The root mean square pulsation pressure coefficient is calculated based on the detrended term and the pressure time domain data with non-physical frequency components removed.

2. The launch vehicle pulsation pressure test data processing method according to claim 1, characterized in that: Obtain the original pressure of the wind tunnel test, calculate the time domain data of the pressure coefficient based on the wind tunnel dynamic pressure and the reference pressure, and draw a curve of the time domain data of the pressure coefficient changing with time, including: in, is the time domain data of the pressure coefficient, is the original pressure, q is the wind tunnel dynamic pressure, P0 is the reference pressure, and t is the time.

3. The launch vehicle pulsation pressure test data processing method according to claim 1, characterized in that: The time domain data of the pressure coefficient is smoothed by using a multi-point smoothing method to obtain pressure coefficient trend item data, including: in, is the pressure coefficient trend item data, is the time domain data of the pressure coefficient, and t is the time.

4. The launch vehicle pulsation pressure test data processing method according to claim 3 is characterized in that: Subtracting the pressure coefficient trend item data from the time domain data of the pressure coefficient to obtain the detrended pressure coefficient data includes: in, is the detrended pressure coefficient data.

5. The launch vehicle pulsation pressure test data processing method according to claim 1, characterized in that: Calculating the power spectrum density of the detrended item pressure coefficient according to the detrended item pressure coefficient data includes: Where PSD is the power spectral density, is the detrended pressure coefficient data, T is the sampling signal duration, t is the time, and ω is the circular frequency.

6. The launch vehicle pulsation pressure test data processing method according to claim 1, characterized in that: Designing a band-stop filter for the non-physical frequency components, processing the detrended pressure coefficient data, and obtaining the detrended pressure time domain data with the non-physical frequency components removed; Among them, C p (t) is the pressure time domain data with trend removed and non-physical frequency components removed, is the detrended pressure coefficient data.

7. The launch vehicle pulsation pressure test data processing method according to claim 1, characterized in that: Based on the detrended term and the pressure time domain data with non-physical frequency components removed, the root mean square pulsation pressure coefficient is calculated, including: in, is the root mean square pulsation pressure coefficient, T is the sampling signal duration, t is time, C p (t) is the pressure time domain data after removing the trend term and non-physical frequency components.

8. A launch vehicle pulsation pressure test data processing system, characterized in that: include: The first calculation module obtains the original pressure of the wind tunnel test, calculates the time domain data of the pressure coefficient according to the wind tunnel dynamic pressure and the reference pressure, and plots the change curve of the time domain data of the pressure coefficient over time; A first processing module performs smoothing processing on the time domain data of the pressure coefficient to obtain pressure coefficient trend item data; A second calculation module, subtracting the pressure coefficient trend item data from the time domain data of the pressure coefficient to obtain the detrended pressure coefficient data; A third calculation module calculates the power spectrum density of the detrended item pressure coefficient according to the detrended item pressure coefficient data, and plots a curve of the power spectrum density versus the circular frequency; The recognition module uses the curve of power spectrum density changing with circular frequency to identify the non-physical frequency components in the power spectrum density; The second processing module designs a band-stop filter for the non-physical frequency components, processes the detrended pressure coefficient data, and obtains the pressure time domain data with detrended items and non-physical frequency components removed; The fourth calculation module calculates the root mean square pulsation pressure coefficient according to the detrended item and the pressure time domain data with non-physical frequency components removed.

9. A computer device comprising a memory, a processor and a computer program stored in the memory, characterized in that: The processor executes the computer program to implement the steps of the method of claim 1.

10. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the steps of the method according to claim 1 are implemented.

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