Plasma exciter structure and asymmetric vortex control system and method

Abstract

The application relates to a plasma exciter structure and an asymmetric vortex control system and method, wherein the exciter structure comprises a copper public positive electrode, two private positive electrodes and a corresponding electrode, the electrodes are configured as a circular sector, a blocking medium is arranged between the electrodes, and a silicon carbide material is used to modify the region between the positive electrodes. In addition, the application also relates to an asymmetric vortex control system which integrates the above exciter structure, an array type flexible pressure sensor, an elongated body tip top, a control module, a high-voltage direct-current source and an alternating-current source. The flexible pressure sensor is arranged on the elongated body tip top and connected to the control module; the exciter structure is located in the middle of the elongated body tip top, and each electrode is also electrically connected to the control module. A hollow channel and a connecting part groove are arranged in the elongated body tip top, and the hollow channel and the connecting part groove are suitable for different specifications of elongated bodies. The application provides an asymmetric vortex control method and system, and makes up for the deficiency of the existing technology in the low energy consumption and high efficiency of the asymmetric vortex control of the elongated rotary body.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of aerodynamics, plasma physics and flow control, and relates to a plasma exciter structure and an asymmetric vortex control system and method. BACKGROUND

[0002] When the slender spinning body (hereinafter referred to as "slender body") missile flies at a large angle of attack, the flow field around the missile often presents a complex multi-vortex structure. The formation, development and rupture of the vortex in the flow field and the generation of asymmetric vortex lead to the nonlinear, unsteady and asymmetric characteristics of the aerodynamic force and moment of the slender body missile, and finally produce strong and random lateral force and yaw moment in the large angle of attack without sideslip. At this time, the conventional control surfaces such as vertical tail and horizontal tail on the missile body are submerged in the turbulent wake and cannot provide the necessary lateral and directional control force. Once the sideslip phenomenon occurs, complex and unpredictable movements such as lateral / side deviation and roll oscillation will occur.

[0003] The Chinese patent CN108235553 A entitled "Sliding discharge exciter and plasma flow control method thereof for slender body" can control the position and intensity of induced vortex and produce asymmetric induced vortex, but the volume force of the sliding discharge exciter is limited, and there is no effective closed-loop control method to realize real-time control in multiple states. In addition, the imperfection of the control system and the increase of energy consumption also limit the use of the exciter. SUMMARY

[0004] The first aspect of the present application aims to provide a plasma exciter structure to solve the technical problem of limited efficiency improvement of the exciter caused by three parallel strip electrodes in the above-mentioned patent. By optimizing the electrode configuration of the exciter structure to a circular sector and modifying the surface coating, the efficiency of the plasma exciter using the structure is improved.

[0005] The second aspect of the present application aims to provide an asymmetric vortex control system which applies the above-mentioned plasma exciter structure and has the characteristics of high efficiency and precision in controlling the asymmetric vortex of the slender body.

[0006] The third aspect of the present application aims to provide an asymmetric vortex control system method which is based on the above-mentioned asymmetric vortex control system.

[0007] The technical scheme of the first aspect of the application is: a plasma exciter structure, comprising a common positive electrode, two private positive electrodes, a ground electrode and a barrier medium; the common positive electrode, the two private positive electrodes and the ground electrode are made of copper, the common positive electrode and the two private positive electrodes are in the shape of a circular sector, the barrier medium is between the common positive electrode and the two private positive electrodes and the ground electrode, and is made of polyimide; the position of the ground electrode corresponds to the inner circle of each positive electrode; and the area between the common positive electrode and the two private positive electrodes is a material modification zone.

[0008] Further, the number of the common positive electrode and the two private positive electrodes of the plasma exciter structure is 10 respectively, and the number of the ground electrode corresponds to the number and position of the positive electrode; the modification material of the modification zone is silicon carbide material, and thus the plasma exciter structure composed of the silicon carbide material is a wide sector plasma exciter structure modified by silicon carbide material.

[0009] The technical scheme of the second aspect of the application is: an asymmetric vortex control system, which applies the wide sector plasma exciter structure modified by silicon carbide material, and further comprises an array type flexible pressure sensor, an elongated body tip top, a control module, and a high-voltage direct-current source and a high-voltage alternating-current source electrically connected to the control module respectively; the flexible pressure sensor is arranged at the top and tail of the elongated body tip top and is electrically connected to the control module; the wide sector plasma exciter structure modified by silicon carbide material is arranged in the middle of the elongated body tip top, and the common positive electrode, the two private positive electrodes and the ground electrode thereon are electrically connected to the control module respectively; the elongated body tip top is internally provided with a hollow channel, the hollow channel penetrates through a connecting portion on the elongated body tip top, and the connecting portion is provided with a connecting portion groove to adapt to elongated bodies of different specifications.

[0010] The technical scheme of the third aspect of the application is: an asymmetric vortex control method, which is based on the asymmetric vortex control system and uses the array type flexible pressure sensor to capture pressure data of the elongated body tip top to represent the vortex state, and realizes the use of the common positive electrode, the two private positive electrodes, the high-voltage direct-current source and the high-voltage alternating-current source by judging the vortex state.

[0011] The application has the following characteristics:

[0012] The asymmetric vortex control method, the division and selection of the control unit: first, the orientation of the vortex is determined by using the flexible pressure-sensitive sensor 1, and then the control area corresponding to the elongated body is determined by using the orientation, and any positive electrode in the control area is set as the e1 electrode, the clockwise positive electrode is the e2 electrode, and the counterclockwise positive electrode is the e3 electrode, and the above three electrodes form a control unit. The division and selection of the control mode: 1. Low-power excitation mode (mode 1), in this mode, only the e1 electrode is provided with an experimental test pulse voltage, a pulse width and a pulse frequency, and the control module 4 controls the high-voltage alternating current source 6 to provide energy input for the above-mentioned electrode; 2. Positive direct current excitation mode (mode 2), the e1 electrode is provided with an experimental test pulse voltage, a pulse width and a pulse frequency, and the e2 or e3 electrode is provided with a positive direct current voltage, and the control module 4 controls the high-voltage alternating current source 6 to provide energy input for the e1 electrode, and the control module 4 controls the high-voltage direct current source 5 to provide energy input for the e2 or e3 electrode; 3. Negative direct current excitation mode (mode 3), the e1 electrode is provided with an experimental test pulse voltage, a pulse width and a pulse frequency, and the e2 or e3 electrode is provided with a negative direct current voltage, and the control module 4 controls the high-voltage alternating current source 6 to provide energy input for the e1 electrode, and the control module 4 controls the high-voltage direct current source 5 to provide energy input for the e2 or e3 electrode; 4. Dynamic excitation mode (mode 4), the e1 electrode is provided with an experimental test pulse voltage, a pulse width and a pulse frequency, and the e2 and e3 electrodes are dynamically selected in the positive and negative direct current voltages within a certain threshold value. The control module 4 controls the high-voltage alternating current source 6 to provide energy input for the e1 electrode, and the control module 4 controls the high-voltage direct current source 5 to provide energy input for the e2 or e3 electrode.

[0013] The beneficial effects of the present application are:

[0014] 1. The present application provides an asymmetric vortex control method and system of a silicon carbide material modified wide sector plasma exciter, which makes up for the deficiencies of the existing technology in the low energy consumption and high efficiency of the asymmetric vortex control of the elongated body. The method can efficiently control the asymmetric vortex appearing on the back of the elongated body during high-speed flight, and provides an important reference value for the engineering application of the asymmetric vortex control of the elongated body.

[0015] 2. The present application provides an asymmetric vortex control method of a silicon carbide material modified wide sector plasma exciter, which controls the asymmetric vortex in different areas through the selection of the control unit and the control mode, covers all areas of the tip of the elongated body, and ensures the stability of the flight of the elongated body.

[0016] 3. The present application provides an asymmetric vortex control system of a silicon carbide material modified wide sector plasma exciter, which greatly improves the control efficiency of the wide sector plasma exciter after material modification, and all electrodes are realized through a magnetron sputtering process, thereby reducing the manufacturing cost and process complexity.

[0017] 4. The wide sector plasma actuator modified by silicon carbide material asymmetric vortex control system of the present application, through the connection control system, the current back area of the slender body is feedback controlled, and different adaptive control modes are adopted to control the variable attack angle state, so as to achieve the optimal asymmetric vortex control effect. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 is the structural schematic diagram of the asymmetric vortex control system of the present application.

[0019] Figure 2 is the structural schematic diagram of the plasma actuator of the present application.

[0020] Figure 3 is the flow schematic diagram of the asymmetric vortex control method of the silicon carbide material modified wide sector plasma actuator slender body of the present application.

[0021] Figure 4 is the flow schematic diagram of the control module in the asymmetric vortex control system of the silicon carbide material modified wide sector plasma actuator slender body of the present application.

[0022] Figure 5 is the plasma actuator jet state diagram and the asymmetric vortex control state diagram in the asymmetric vortex control system of the silicon carbide material modified wide sector plasma actuator slender body of the present application.

[0023] In the figure: 1.1 / 1.3 flexible pressure sensitive sensor; 2. silicon carbide material modified wide sector plasma actuator structure; 2.1, common positive electrode; 2.2 / 2.3, private positive electrode; 2.4, ground electrode; 2.5, blocking medium; 2.6, modified area; 3, slender body tip top; 3.1, top; 3.2, middle; 3.3, tail; 3.4, connecting part; 3.5, connecting part groove; 4, control module; 5, high voltage DC power supply; 6, high voltage AC power supply. DETAILED DESCRIPTION

[0024] The present application will be described in detail below in combination with the drawings and specific embodiments.

[0025] Referring to Figure 1 and Figure 2 , some embodiments of the present application provide a plasma actuator structure applied to control the asymmetric vortex of a slender body. The configuration plasma actuator structure is as shown in Figure 2As shown, the main components include common positive electrode 2.1, private positive electrode 2.2 / 2.3, ground electrode 2.4 and blocking medium 2.5, the materials of common positive electrode 2.1, private positive electrode 2.2 / 2.3 and one ground electrode 2.4 are copper, the forming mode is magnetron sputtering, the sputtering time is 48 hours, the configuration of common positive electrode 2.1 and private positive electrode 2.2 / 2.3 is circular sector, the angle of circular sector is 240°, the blocking medium 2.5 is between common positive electrode 2.1 and private positive electrode 2.2 / 2.3 and ground electrode 2.4, the material is polyimide, the ground electrode 2.4 is circular sector, the angle of circular sector is 360°, the position corresponds to the inner circle of each positive electrode, the area between common positive electrode 2.1 and private positive electrode 2.2 / 2.3 is material modification area 2.6, the modified material is silicon carbide material, the film forming mode is magnetron sputtering, the sputtering time is 48 hours.

[0026] It should be noted that the number of common positive electrode 2.1 and private positive electrode 2.2, 2.3 of the plasma exciter structure is 10 respectively, the arrangement mode is downstream direction, the number of ground electrode 2.4 corresponds to the number and position of positive electrode. The plasma exciter structure thus formed is a silicon carbide material modified wide sector plasma exciter structure 2.

[0027] In some embodiments, the present application also provides a system of asymmetric vortex. The system is composed of Figure 1 As shown, the system mainly consists of 6 parts: flexible pressure sensor 1, silicon carbide material modified wide sector plasma exciter structure 2 and slender body tip 3 and control module 4, high voltage DC source 5 and high voltage AC source 6. The flexible pressure sensor 1 is an array type flexible pressure sensor 1 made of polyimide, model RX-M0808M, which is arranged at the top 3.1 and tail 3.3 of the slender body tip 3 to collect surface pressure data in real time. The flexible pressure sensor 1 is electrically connected with the control module 4. The silicon carbide material modified wide sector plasma exciter structure 2 is arranged in the middle 3.2 of the slender body tip 3, and the common positive electrode 2.1, private positive electrode 2.2, 2.3 and ground electrode 2.4 thereon are respectively electrically connected with the control module 4; the slender body tip 3 is made of quick replaceable quartz glass, and a hollow channel is arranged in the slender body tip 3, which penetrates through the connecting part 3.4 on the slender body tip 3 for connecting the excitation source and the control module 4. The connecting part 3.4 is provided with a connecting part groove 3.5 to adapt to different specifications of slender bodies.

[0028] The working principle of the asymmetric vortex control system of the present application for controlling the closed loop method of asymmetric vortex of slender body is as follows Figure 3As shown, the array of flexible pressure sensors installed on the tip of the slender body detects the pressure changes caused by the change of angle of attack or environmental changes in real time and sends these data to the asymmetric vortex control module for online monitoring and control. When the control module detects the generation of asymmetric vortex in the leeward area by analyzing the sensor data, the following is performed:

[0029] The data S of the flexible pressure sensor 1 represents the vortex state, then

[0030]

[0031] When S = 0, it represents that the current slender body surface flow field is in normal state, and when S = 1, it represents that the current slender body surface is in asymmetric vortex state. According to the relevant positioning method, the asymmetric vortex position R (X / D, θ) can be determined. X / D is the non-dimensional position of the vortex relative to the starting point of the slender body. θ is the angle between the vortex core position and the starting point of the slender body.

[0032] The asymmetric vortex control system method using silicon carbide material modified circular sector plasma exciter structure 2 includes three positive electrodes and one ground electrode. The electrode number e is determined by calculating the relative position of the three positive electrodes and the asymmetric vortex position R:

[0033]

[0034] Wherein,

[0035]

[0036] The control function under different control modes is defined as V(e n ,k m ), where e n is defined as the electrode number, n takes the value range (1, 2, 3), k m is defined as the control mode, and m control mode is divided into: low-power excitation mode (m = a); positive direct current excitation mode (m = b); negative direct current excitation mode (m = c); and dynamic excitation mode (m = d). Then:

[0037]

[0038] First, the orientation of the vortex is determined by using the positioning method, then the control area corresponding to the orientation is set, any positive electrode in the control area is set as e1 electrode, the positive electrode clockwise is set as e2 electrode, and the positive electrode counterclockwise is set as e3 electrode, and finally the silicon carbide material modified wide sector plasma exciter 3 installed on the tip is activated for control. The specific control method is:

[0039] 1. Select low power excitation mode (Mode 1), in which only the voltage across e1 electrode is raised to the excitation voltage (experimental experience voltage: 14kV). According to the positioning data, if the asymmetric vortex is not controlled, the system will maintain the current excitation state.

[0040]

[0041] 2. If Mode 1 cannot effectively control the asymmetric vortex, the system switches to positive DC excitation mode (Mode 2), raising the voltage across e1 electrode to the excitation voltage (experimental experience voltage: 14kV), while applying a positive DC voltage (experimental experience voltage: 10kV) to e2 or e3 electrode;

[0042]

[0043] If the asymmetric vortex is still not controlled, the system switches to negative DC excitation mode (Mode 3), in which the voltage across e1 electrode is still the experimental experience voltage, while the voltage across e2 or e3 electrode is a negative DC voltage of the experimental experience voltage;

[0044]

[0045] If the above three modes fail, finally dynamic excitation mode (Mode 4) will be adopted, in which the voltage across e1 electrode is fixed at the experimental experience voltage, and the voltage across e2 or e3 electrode is dynamically selected between the threshold voltage (10kV-14kV) positive and negative DC voltage until the asymmetric vortex is effectively controlled. All voltage values and modes of the present invention are based on experimental measurements, which constitute the core of the control method.

[0046]

[0047] Referring to Figure 4 , an asymmetric vortex control system of the present invention is arranged on the tip 3 of the slender body with arrayed flexible pressure sensitive sensors 1, which are responsible for capturing pressure data. These data are processed through digital-to-analog converter and compared with the pressure threshold value in historical experience. Once the data are detected to meet the characteristics of the leeward asymmetric vortex, the system transmits these data to the signal acquisition card. Then, the closed-loop control method selects the current slender body motion state and selects the control mode, adjusts the voltage through the drive control circuit and selects the corresponding electrode for precise control. If the initial control attempt fails, the system will start the process again to try control; if the control is successfully achieved, the system maintains the excitation state until the asymmetric vortex dissipates. In addition, the control system also includes a high-voltage AC source and a high-voltage DC source to meet the needs of different excitation sources, Figure 5 to achieve the asymmetric vortex control effect using the above-mentioned system.

[0048] The experimental method and system have the following advantages: first, it fills the gap in the integration of the tip of the slender body of revolution model and the plasma actuator, and the characteristics of quick replacement and multiple excitation modes help to promote the research and application of various types of slender bodies of revolution; secondly, we propose a method based on material modification to improve the efficiency of the wide sector plasma actuator, which can improve the speed and volume force of the induced jet by reducing the residual charge in the discharge area, thereby improving the control efficiency; thirdly, the application also introduces a new type of wide sector plasma actuator configuration suitable for controlling the asymmetric vortex of the slender body, which solves the limitations of the traditional configuration by covering the tip of the slender body with three positive electrodes; in addition, we also propose a new method to control the asymmetric vortex using the wide sector plasma actuator, which is flexible and convenient, and has high universality and high control efficiency; finally, compared with the traditional configuration, the control device has less interference with the flow field of the slender body, higher efficiency in controlling the asymmetric vortex, and higher reliability.

Claims

1. An asymmetric vortex control method, characterized by, Firstly, the array flexible pressure sensor (1) is used to determine the orientation of the vortex, and secondly, the control area corresponding to the tip of the slender body (3) is determined by using the orientation. Through the selection of the control unit and the control mode, the control of the asymmetric vortex in different areas is adapted, as follows: setting any positive electrode in the control area as the electrode, the clockwise positive electrode as the electrode, and the counterclockwise positive electrode as the electrode, and the above three electrodes form a control unit. Low power consumption excitation mode, in which only The electric parameter between the electrodes is the experimental test pulse voltage, pulse width and pulse frequency, and the control module (4) controls the high-voltage alternating current source (6) to provide energy input for the above electrodes. positive direct current excitation mode, will The electrical parameters between the electrodes are tested by pulse voltage, pulse width and pulse frequency. or The electrode applies a positive direct current voltage, and the control module (4) controls the high-voltage alternating current source (6) to The electrode provides energy input, and the control module (4) controls the high-voltage direct current source (5) to or The electrode provides energy input; negative direct current excitation mode, The electrical parameter between the electrodes is the experimental test pulse voltage, pulse width and pulse frequency. or The voltage between the electrodes is a negative direct current voltage, and the control module (4) controls the high-voltage alternating current source (6) to provide energy input for the electrodes, and the control module (4) controls the high-voltage direct current source (5) to or provide energy input for the electrodes; Dynamic excitation mode, The electrical parameter between the electrodes is the experimental test pulse voltage, pulse width and pulse frequency. With The electrode is dynamically selected in the positive and negative DC voltage within a certain threshold, and the control module (4) controls the high-voltage AC source (6) to provide energy input for the electrode. The control module (4) controls the high-voltage DC source (5) to provide energy input for the electrode. Or The electrode provides energy input.

2. An asymmetric vortex control system for implementing the asymmetric vortex control method of claim 1, characterized by, The array flexible pressure sensor (1), the elongated body tip (3), the control module (4), and the high-voltage direct-current source (5) and the high-voltage alternating-current source (6) electrically connected with the control module (4) respectively; the array flexible pressure sensor (1) is arranged at the top (3.1) and the tail (3.3) of the elongated body tip (3), and is electrically connected with the control module (4); the plasma exciter structure is arranged in the middle (3.2) of the elongated body tip (3), and the hollow channel is arranged in the elongated body tip (3), the hollow channel penetrates through the connecting part (3.4) on the elongated body tip (3), and the connecting part (3.4) is provided with a connecting part groove (3.5) to adapt to different specifications of the elongated body.

3. The asymmetric vortex control system of claim 2, wherein, The plasma exciter structure includes a common positive electrode (2.1), a first private positive electrode (2.2) and a second private positive electrode (2.3), a ground electrode (2.4) and a barrier medium (2.5); the materials of the common positive electrode (2.1), the first private positive electrode (2.2) and the second private positive electrode (2.3), and the ground electrode (2.4) are copper, the common positive electrode (2.1) and the first private positive electrode (2.2) and the second private positive electrode (2.3) are configured as a circular sector, the barrier medium (2.5) is between the common positive electrode (2.1) and the first private positive electrode (2.2) and the second private positive electrode (2.3) and the ground electrode (2.4), and the material is polyimide; the ground electrode (2.4) is located corresponding to the inner circle of each positive electrode, and the area between the common positive electrode (2.1) and the first private positive electrode (2.2) and the second private positive electrode (2.3) is a material modification area (2.6).

4. The asymmetric vortex control system of claim 3, wherein, The number of the common positive electrode (2.1) and the first private positive electrode (2.2) and the second private positive electrode (2.3) of the plasma exciter structure is 10 respectively, and the number of the ground electrode (2.4) corresponds to the number and position of the positive electrode, and the material of the modification area (2.6) is silicon carbide material.

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