High-speed rail tunnel transient pressure wave efficient generator based on harmonic synthesis method

Abstract

The invention relates to the field of high-speed railway tunnel aerodynamics, in particular to a high-speed railway tunnel transient pressure wave efficient generator based on a harmonic synthesis method, which comprises a transient pressure wave generation module, a data pre-processing module, a core processing module, a transient pressure wave output module and a target experiment model, the transient pressure wave generation module generates a positive pressure waveform and a negative pressure waveform; the data pre-processing module is used for calculating characteristic data of field test pressure waves; the core processing module adopts a harmonic synthesis method to reconstruct pressure wave data, and sends pressure wave time history data to the transient pressure wave output module to generate positive pressure waves and negative pressure waves; and the transient pressure wave output module is connected with the core processing module and is used for outputting the positive pressure wave and the negative pressure wave to a target test model. The generator can efficiently simulate pressure waves under various driving conditions, and time-frequency information of actual pressure waves is reserved, so that the test efficiency and precision are improved.

Description

Technical Field

[0001] The invention relates to the field of aerodynamics of high-speed railway tunnels, in particular to a high-speed railway tunnel transient pressure wave efficient generator based on a harmonic synthesis method. Background Art

[0002] With the rapid expansion of high-speed railway networks, the problem of pressure waves generated by trains running in tunnels has gradually attracted attention. Tunnel pressure waves are mainly caused by the pressure change phenomenon caused by the interaction between high-speed trains and the air in the tunnel when they are running in the tunnel. When the train enters the tunnel at high speed, the air in front of it is compressed, resulting in an increase in air density and the formation of positive pressure waves; correspondingly, when the train leaves the tunnel, the air in the tunnel generates negative pressure waves due to the expansion of the rear of the train. These pressure waves propagate in the tunnel in the form of waves, and their propagation speed depends on the physical properties of the air and the geometric characteristics of the tunnel. The hazards of tunnel pressure waves involve multiple aspects such as train operation safety, tunnel structural stability, environmental impact and passenger comfort. Therefore, the study and control of tunnel pressure waves are of great practical significance.

[0003] Due to the difficulty, high cost and poor repeatability of field testing, experimental methods are usually used to study the impact of pressure waves in high-speed railway tunnels on tunnel structures, passengers and the surrounding environment. The accurate simulation and use of pressure waves in the test can better predict and evaluate the stress conditions of the tunnel structure in actual operation, thereby optimizing the design of tunnels, ancillary facilities or train structures, and improving structural safety and durability. In order to evaluate the impact of pressure waves on the above aspects, it is necessary to accurately simulate them in a laboratory environment. Traditional experimental methods use harmonics or rectangular waves to simulate pressure waves in tunnels. Such methods often cannot accurately capture and simulate dynamically changing pressure wave phenomena in real time, which limits the in-depth understanding and effective control of complex airflow behavior in tunnels. Summary of the invention

[0004] The method of the present invention simulates pressure waves under various driving conditions and retains the time-frequency information of actual pressure waves. It proposes an efficient generator of transient pressure waves in high-speed railway tunnels based on the harmonic synthesis method, which can more accurately predict and evaluate the impact of pressure waves on tunnel structures and provide a scientific basis for tunnel design.

[0005] In order to achieve the above objectives, the following technical solutions are proposed:

[0006] A high-speed railway tunnel transient pressure wave efficient generator based on harmonic synthesis method, including a transient pressure wave generation module, a data pre-processing module, a core processing module, a transient pressure wave output module and a target test model;

[0007] The transient pressure wave generating module generates an initial positive pressure waveform and a negative pressure waveform for simulating the pressure change generated when a high-speed train passes through a tunnel;

[0008] The data pre-processing module is connected to the transient pressure wave generating module, and the data pre-processing module is used to calculate the characteristic data of the pressure wave of the tunnel field test;

[0009] The core processing module is connected to the data pre-processing module, and uses the harmonic synthesis method to reconstruct the pressure wave data, generates pressure wave time history data that retains the actual transient pressure wave spectrum characteristics according to the characteristic data of the pressure wave, and sends the pressure wave time history data to the transient pressure wave output module to generate positive pressure waves and negative pressure waves;

[0010] The transient pressure wave output module is connected to the core processing module and is used to output positive pressure waves and negative pressure waves to the target test model.

[0011] Preferably, the positive pressure waveform and the negative pressure waveform range from -10000Pa to 10000Pa, and the main frequency and spectrum peak of the pressure wave are obtained according to the positive pressure waveform and the negative pressure waveform. The characteristic data of the pressure wave includes the average value and standard deviation of the pressure wave.

[0012] Preferably, the main frequency peak and the spectrum peak are calculated according to the Fourier transform formula, and the calculation formula of the Fourier transform is:

[0013]

[0014] Among them, p n ={p0,…,p n-1} is the field test pressure wave sequence; e -i2π / N is the original n-square root of 1; k represents the frequency domain index, ranging from 0 to N-1; n is the number of segments of the field test pressure wave sequence, and N is a positive integer greater than 1.

[0015] Preferably, the positive pressure wave is generated by an air compressor, and the positive pressure waveform is generated by adjusting the output air pressure of the air compressor; the negative pressure wave is generated by a vacuum machine, and the negative pressure waveform is generated by adjusting the suction rate of the vacuum machine; the air compressor and the vacuum machine work together to simulate the pressure changes when a high-speed train passes through a tunnel.

[0016] Preferably, the positive pressure wave and the negative pressure wave are transmitted to the target test model by a pressure waveguide.

[0017] Preferably, the core processing module further includes a processor and a memory, and the processor is used to read the characteristic data of the pressure wave provided by the data pre-processing module.

[0018] Preferably, the harmonic synthesis method retains the time-frequency information of the actual pressure wave, so as to make the reconstructed pressure wave close to the actual pressure wave, and the target test model is used to simulate the stress state of the field facility under the influence of the pressure wave.

[0019] Preferably, the core formula of the harmonic synthesis method is:

[0020]

[0021] Where j represents any point in space, j = 1, 2, 3, ..., n; P j (t) is the reconstructed pressure wave time history, in Pa; t represents time; m represents a continuous integer value in the range [1, j]; l represents a continuous integer value in the range [1, N]; N is the number of frequency segments, Δω=ω max / N is the frequency increment, ω max is the upper cutoff frequency; φ ml is an independent random phase angle uniformly distributed in the interval [0,2π]; ω ml is the double index frequency; H jm (ω ml ) is a complex matrix, θ jm (ω ml ) is H jm (ω ml )'s complex angle;

[0022] θ jm (ω ml ) is calculated as:

[0023]

[0024] Where n is a point in space, Im[H jm (ω ml )] is the complex matrix H jm (ω ml ) is the imaginary part, Re[H jm (ω ml )] is the complex matrix H jm (ω ml ) is the real part of .

[0025] Compared with the prior art, the present invention has the following beneficial effects: the present invention can efficiently simulate pressure waves under various driving conditions and retain the time-frequency information of actual pressure waves, thereby improving the efficiency and accuracy of the test. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 is a flow chart of a high-speed railway tunnel transient pressure wave efficient generator based on harmonic synthesis method in Example 1;

[0027] Figure 2is a connection diagram of the high-speed railway tunnel transient pressure wave efficient generator based on the harmonic synthesis method in Example 1;

[0028] Figure 3 is a schematic diagram of the transient pressure wave generation process in Example 1;

[0029] Figure 4 This is the time history diagram of the transient pressure wave generated in the experiment. DETAILED DESCRIPTION

[0030] The present invention is further described in detail below in conjunction with test examples and specific implementation methods. However, this should not be understood as the scope of the above subject matter of the present invention being limited to the following embodiments, and all technologies realized based on the content of the present invention belong to the scope of the present invention.

[0031] In addition, in the description of the technical solution of the present invention, unless otherwise clearly specified / defined / restricted, the terms "set", "install", "connect", "connected", "provided with", "laid", and "arranged" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection, and can be welding, riveting, bolting, threading, and other commonly used connection means in the field. This connection can be a mechanical connection, an electrical connection, or a communication connection; it can be a direct connection, or an indirect connection through an intermediate medium, and it can be the internal connection of two elements.

[0032] Example 1

[0033] An efficient generator of transient pressure waves in high-speed railway tunnels based on harmonic synthesis method, such as Figure 1 As shown, it includes a transient pressure wave generation module, a data pre-processing module, a core processing module, a transient pressure wave output module and a target test model;

[0034] The transient pressure wave generating module generates an initial positive pressure waveform and a negative pressure waveform to simulate the pressure change generated when a high-speed train passes through a tunnel;

[0035] The data pre-processing module is connected to the transient pressure wave generating module, and the data pre-processing module is used to calculate the characteristic data of the pressure wave of the tunnel field test;

[0036] The core processing module is connected to the data pre-processing module, and uses the harmonic synthesis method to reconstruct the pressure wave data, generates pressure wave time history data that retains the actual transient pressure wave spectrum characteristics according to the characteristic data of the pressure wave, and sends the pressure wave time history data to the transient pressure wave output module to generate positive pressure waves and negative pressure waves;

[0037] The transient pressure wave output module is connected to the core processing module and is used to output positive pressure waves and negative pressure waves to the target test model.

[0038] The present invention aims to provide a device that can efficiently simulate transient pressure waves in high-speed railway tunnels during experiments, and can repeatedly output pressure waves in high-speed railway tunnels in a cycle to analyze the stress characteristics of the structure under the action of cyclic pressure waves, so as to improve the efficiency and accuracy of aerodynamic test research in high-speed railway tunnels. The device is based on the harmonic synthesis method and integrates a transient pressure wave generation module, a data pre-processing module, a core processing module, and a transient pressure wave output module. The target test model may include, but is not limited to: tunnel lining structure, train structure, and tunnel ancillary facilities. The transient pressure wave generation module can generate positive and negative pressure waveforms in the range of about -10000 to 10000Pa, and generate pressure waves when simulating a train passing through a tunnel through the coordinated work of an air compressor and a vacuum machine; the data pre-processing module is used to calculate the characteristic data of the field test pressure wave data input by the user, including the average value and standard deviation, as well as the main frequency and spectrum peak of the pressure wave obtained based on Fourier transform analysis; the core processing module is used to read the pressure wave characteristic data and reconstruct the pressure wave data using the harmonic synthesis method; the transient pressure wave output module is responsible for outputting the pressure wave time history data generated by the core processing module to the test model, which is used to simulate the stress state of ancillary facilities such as tunnel lining, trains or distribution boxes under the influence of pressure waves. The present invention realizes the rapid processing and precise control of pressure wave data through real-time harmonic synthesis analysis, and improves the automation and intelligence level of the test; the self-developed algorithm combines the actual field data for spectrum analysis, so that the device can adapt to a variety of tunnel-related structures and working conditions, and has wide applicability and high practicality.

[0039] As a specific embodiment, test preparation: Before the test begins, the various modules of the device need to be connected. The connection method is as follows: Figure 2 As shown. First, according to the specific design parameters of the high-speed railway tunnel, such as tunnel length, train design speed and actual running speed, prepare the field test pressure wave data and prepare to input it into the processor of the core processing module. At the same time, prepare the transient pressure wave generation module, data pre-processing module, core processing module and transient pressure wave output module, and ensure that the size, material and performance of all modules and test models meet the design requirements.

[0040] Installation of transient pressure wave generator module: Install air compressors and vacuum machines at appropriate locations in the indoor test site to ensure that they have a stable power supply and are not interfered by external factors. By adjusting the output pressure of the air compressor and the air extraction rate of the vacuum machine, positive and negative pressure waveforms caused by simulated train operation are generated.

[0041] Data pre-processing module setting: A data pre-processing module is set near the transient pressure wave generation module, including a user input panel and a Fourier transform program. The user input panel is used to receive the field test pressure wave data input by the user, and the Fourier transform program is used to analyze the input pressure wave data, obtain the main frequency and spectrum peak of the pressure wave, and calculate the characteristic data of the pressure wave data, such as the mean value and standard deviation. The core formula of Fourier transform is as follows:

[0042]

[0043] In the formula, p n ={p0,…,p n-1} is the field test pressure wave sequence input by the user; e -i2π / N is the primitive nth root of 1.

[0044] Core processing module configuration: connect the data pre-processing module and the core processing module. The core processing module contains a processor and a memory, which is used to read the pressure wave characteristic data provided by the data pre-processing module, reconstruct the pressure wave data using the harmonic synthesis method, and generate pressure wave time history data that matches the actual transient pressure wave. The specific generation process of transient pressure waves in the tunnel is as follows: Figure 3 shown.

[0045] Based on the main frequency and spectrum peak of the input pressure wave, multiple sine waves are synthesized by harmonic synthesis method and mixed together in a certain proportion to reconstruct a new pressure wave waveform. Figure 4 Specific embodiments are given. Figure 4 As shown, the user inputs the field test pressure wave data through the data pre-processing module, the Fourier transform analyzes the main frequency and spectrum peak of the pressure wave and generates multiple sine waves (about 40), and the harmonic synthesis method synthesizes the sine waves to reconstruct a new pressure wave waveform.

[0046] During the reconstruction process, users can adjust the mean and standard deviation of the pressure wave according to the actual train speed and whether the trains are crossing each other, so as to generate pressure waves under different driving conditions. The core formula of the harmonic synthesis method is as follows:

[0047]

[0048] Where P j (t) is the reconstructed pressure wave time history, in Pa; N is the number of frequency segments; Δω=ω max / N is the frequency increment, where ω max is the upper cutoff frequency; φ ml is an independent random phase angle uniformly distributed in the interval [0,2π]; ω ml is the double index frequency; θ jm (ω ml ) is Hjm (ω ml ) is calculated as follows:

[0049]

[0050] In the formula, Im[H jm (ω ml )] and Re[H jm (ω ml )] represent the complex matrix H jm (ω ml )’s imaginary and real parts.

[0051] Transient pressure wave output module installation: Connect the core processing module with the transient pressure wave output module, including the installation of the pressure waveguide and pressure sensor. The pressure waveguide is used to transmit the generated pressure wave to the target test model, and the pressure sensor is used to monitor the transmission status and intensity of the pressure wave.

[0052] Target test model layout: A simulated tunnel lining structure, train carriage structure or tunnel ancillary facilities are installed at the output end of the transient pressure wave output module, and stress sensors and displacement sensors are installed on them to record and analyze the impact of pressure waves on these structures.

[0053] Test and debugging: Conduct a series of tests to simulate the pressure waves generated when a train passes through a tunnel under different driving conditions, as well as the stress state of different tunnel structures under the action of pressure waves. Adjust the parameters of each module according to the test results until the expected simulation effect is achieved.

[0054] Through the above steps, the effective operation of the high-speed railway tunnel transient pressure wave efficient generator based on the harmonic synthesis method can be ensured, providing strong technical support for the aerodynamic research, structural design optimization and safety assessment of high-speed railway tunnels.

[0055] The invention can efficiently generate transient pressure waves generated by high-speed trains passing through tunnels under various driving conditions in indoor tests by means of user input and reconstruction by harmonic synthesis method, and fully retain the time-frequency information of the actual pressure waves, thereby improving the efficiency and accuracy of aerodynamic tests in high-speed railway tunnels. The device consists of a transient pressure wave generation module, a data pre-processing module, a core processing module and a transient pressure wave output module. The transient pressure wave generation module generates positive and negative pressures through an air compressor and a vacuum machine; the data pre-processing module is used to calculate the characteristic data of the field test pressure wave data input by the user, including the mean value and standard deviation, as well as the main frequency and spectrum peak of the pressure wave obtained based on Fourier transform analysis; the core processing module is used to read the pressure wave characteristic data and reconstruct the pressure wave data by using the harmonic synthesis method; the transient pressure wave output module is responsible for outputting the pressure wave time history data generated by the core processing module to the test model. The device has the characteristics of high efficiency, strong versatility and high reliability. It retains the time-frequency characteristics of the real pressure wave while efficiently generating transient pressure waves, and provides effective test support data for the stress characteristics and service performance of high-speed railway tunnels and related structures under the action of pressure waves. Through the generator of the present invention, researchers can more accurately predict and evaluate the impact of pressure waves on tunnel structures, provide a scientific basis for tunnel design, and also help improve the safety of train operation and the comfort of passengers. In addition, the efficiency and versatility of the device make it have important application value in scientific research and engineering practice.

[0056] Finally, it should be noted that the embodiments described in detail above are only the best practices of the invention and cannot be used to limit the scope of rights of the invention. Equivalent replacement of the technical solutions recorded in the aforementioned embodiments does not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the invention, and they should all be included in the scope of the claims and description of the invention.

Claims

1. An efficient generator of transient pressure waves in high-speed railway tunnels based on harmonic synthesis method, characterized in that: It includes a transient pressure wave generation module, a data pre-processing module, a core processing module, a transient pressure wave output module and a target test model; The transient pressure wave generating module generates an initial positive pressure waveform and a negative pressure waveform for simulating the pressure change generated when a high-speed train passes through a tunnel; The data pre-processing module is connected to the transient pressure wave generating module, and the data pre-processing module is used to calculate the characteristic data of the pressure wave of the tunnel field test; The core processing module is connected to the data pre-processing module, and uses the harmonic synthesis method to reconstruct the pressure wave data, generates pressure wave time history data that retains the actual transient pressure wave spectrum characteristics according to the characteristic data of the pressure wave, and sends the pressure wave time history data to the transient pressure wave output module to generate positive pressure waves and negative pressure waves; The transient pressure wave output module is connected to the core processing module and is used to output positive pressure waves and negative pressure waves to the target test model.

2. The high-speed railway tunnel transient pressure wave efficient generator based on harmonic synthesis method as claimed in claim 1, characterized in that: The positive pressure waveform and the negative pressure waveform have a range of -10000Pa to 10000Pa. The main frequency and spectrum peak of the pressure wave are obtained according to the positive pressure waveform and the negative pressure waveform. The characteristic data of the pressure wave include the average value and standard deviation of the pressure wave.

3. The high-speed railway tunnel transient pressure wave efficient generator based on harmonic synthesis method as claimed in claim 2, characterized in that: The main frequency peak and the spectrum peak are calculated according to the Fourier transform formula. The calculation formula of Fourier transform is: Among them, p n ={p0,···,p n-1 } is the field test pressure wave sequence; e -i2πN is the original n-square root of 1; k represents the frequency domain index, ranging from 0 to N-1; n is the number of segments of the field test pressure wave sequence, and N is a positive integer greater than 1.

4. The high-speed railway tunnel transient pressure wave efficient generator based on harmonic synthesis method as claimed in claim 1, characterized in that: The positive pressure wave is generated by an air compressor, and the positive pressure waveform is generated by adjusting the output air pressure of the air compressor; The negative pressure wave is generated by a vacuum machine, and the negative pressure waveform is generated by adjusting the suction rate of the vacuum machine; the air compressor and the vacuum machine work together to simulate the pressure change when a high-speed train passes through a tunnel.

5. The high-speed railway tunnel transient pressure wave efficient generator based on harmonic synthesis method as claimed in claim 4, characterized in that: The positive pressure wave and the negative pressure wave are transmitted to the target test model by the pressure waveguide of the transient pressure wave output module.

6. The high-speed railway tunnel transient pressure wave efficient generator based on harmonic synthesis method as claimed in claim 1, characterized in that: The core processing module also includes a processor and a memory, and the processor is used to read the characteristic data of the pressure wave provided by the data pre-processing module.

7. The high-speed railway tunnel transient pressure wave efficient generator based on harmonic synthesis method as claimed in claim 6, characterized in that: The harmonic synthesis method retains the time-frequency information of the actual pressure wave and is used to make the reconstructed pressure wave close to the actual pressure wave. The target test model is used to simulate the stress state of the field facility under the influence of the pressure wave.

8. The high-speed railway tunnel transient pressure wave efficient generator based on harmonic synthesis method as claimed in claim 7, characterized in that: The core formula of the harmonic synthesis method is: Among them, P j (t) is the reconstructed pressure wave time history, j represents any point in space, j = 1, 2, 3, ..., n; P j (t) is the pressure time history at point j, in Pa; t is time; m is a continuous integer value in the range [1, j]; l is a continuous integer value in the range [1, N]; N is the number of frequency segments, Δω=ω max / N is the frequency increment, ω max is the upper cutoff frequency; φ ml is an independent random phase angle uniformly distributed in the interval [0,2π]; ω ml is the double index frequency; H jm (ω ml ) is a complex matrix, θ jm (ω ml ) is H jm (ω ml )'s complex angle; θ jm (ω ml ) is calculated as: Where n is a point in space, Im[H jm (ω ml )] is the complex matrix H jm (ω ml ) is the imaginary part, Re[H jm (ω ml )] is the complex matrix H jm (ω ml ) is the real part of .

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