Plasma exciter structure and asymmetric vortex control system and method

Abstract

The invention relates to a plasma exciter structure and an asymmetric vortex control system and method, the exciter structure comprises a copper public positive electrode, two private positive electrodes and a corresponding ground electrode, the electrode configuration is in a circular fan shape, a blocking medium is arranged between the electrodes, and the area between the positive electrodes is modified by adopting a silicon carbide material. In addition, the invention further relates to an asymmetric vortex control system, and the system integrates the exciter structure, an array type flexible pressure-sensitive sensor, a slender body pinnacle part, a control module, a high-voltage direct current source and an alternating current source. The flexible pressure-sensitive sensor is arranged at the tip of the slender body and is connected with the control module; the exciter structure is located in the middle of the tip of the slender body, and the electrodes are electrically connected with the control module. A hollow channel and a connecting part groove are arranged in the tip part of the slender body to adapt to slender bodies of different specifications. According to the asymmetric vortex control method and system, the defects of low energy consumption and high efficiency of asymmetric vortex control of a slender revolution body in the prior art are overcome.

Description

Technical Field

[0001] The invention belongs to the technical fields of aerodynamics, plasma physics and flow control, and relates to a plasma actuator structure and an asymmetric vortex control system and method. Background Art

[0002] When a slender spiral body (hereinafter referred to as "slender body") missile maneuvers at a high angle of attack, its flow field often presents a complex multi-vortex structure. The formation, development and rupture of the vortex in the flow field and the generation of asymmetric vortices lead to severe nonlinear, unsteady and asymmetric characteristics of the aerodynamic force and torque of the slender body missile, and ultimately generate strong and random lateral forces and yaw moments in the state of no sideslip at a high angle of attack. At this time, conventional control surfaces such as the vertical tail and horizontal tail on the missile body are submerged in the turbulent wake and cannot provide the necessary lateral and lateral control forces. Once the sideslip phenomenon occurs, complex and unpredictable movements such as lateral / lateral deviation and rock oscillation will quickly occur.

[0003] The invention is named Sliding Discharge Exciter and Method for Controlling Plasma Flow of Slender Body Thereof, and the patent number is CN108235553 A in China. Although the sliding discharge exciter can also control the position and strength of the induced vortex and generate an asymmetric induced vortex, the volume force of the sliding discharge exciter is limited, and there is no effective closed-loop control method to achieve real-time control of multiple states. In addition, the incompleteness of the control system and the increased energy consumption also limit the use of the exciter of this configuration. Summary of the invention

[0004] The first aspect of the present invention aims to provide a plasma actuator structure to solve the technical problem in the above-mentioned patent that the three parallel strip electrodes have limited effect on improving the actuator efficiency. By optimizing the electrode configuration of the actuator structure into a circular sector shape and modifying the surface coating, the efficiency of the plasma actuator using the structure is improved.

[0005] The second aspect of the present invention aims to provide an asymmetric vortex control system, which uses the above-mentioned plasma actuator structure and has the characteristics of efficiently and accurately controlling the asymmetric vortex of a slender body.

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

[0007] The technical solution of the first aspect of the present invention is: a plasma exciter structure, including a common positive electrode, two private positive electrodes, a ground electrode and a blocking medium; the material of the common positive electrode, the two private positive electrodes and the ground electrode is copper, the configuration of the common positive electrode and the two private positive electrodes is a circular sector, the blocking medium is between the common positive electrode and the two private positive electrodes and the ground electrode, and the material is 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 area.

[0008] Furthermore, the number of the common positive electrode and the two private positive electrodes of the plasma exciter structure are 10 each, and the number of ground electrodes corresponds to the number and position of the positive electrodes. The modified material of the modified zone is silicon carbide material, and the plasma exciter structure thus constructed is a wide-sector plasma exciter structure modified with silicon carbide material.

[0009] The technical solution of the second aspect of the present invention is: an asymmetric vortex control system, which applies the wide sector plasma actuator structure modified by the above-mentioned silicon carbide material, and also includes an array-type flexible pressure-sensitive sensor, a slender body tip top, a control module, and a high-voltage DC source and a high-voltage AC source electrically connected to the control module respectively; the flexible pressure-sensitive sensor is arranged at the top and tail of the slender body tip top, and is electrically connected to the control module, the wide sector plasma actuator structure modified by the silicon carbide material is arranged in the middle of the slender body tip top, and the common positive electrode, two private positive electrodes and the ground electrode thereon are electrically connected to the control module respectively; a hollow channel is provided inside the slender body tip top, and the hollow channel runs through the connecting part on the slender body tip top, and the connecting part is provided with a connecting part groove to adapt to slender bodies of different specifications.

[0010] The technical solution of the third aspect of the present invention is: an asymmetric vortex control method, based on the above-mentioned asymmetric vortex control system, using an array of flexible pressure-sensitive sensors to capture the pressure data at the top of the slender body tip to represent the vortex state, and through the judgment of the vortex state, the use of a common positive electrode, two private positive electrodes, and a high-voltage DC source and a high-voltage AC source is realized.

[0011] The present invention is also characterized in that:

[0012] Asymmetric vortex closed-loop control method, division and selection of control units: first, use the flexible pressure-sensitive sensor 1 to determine the orientation of the vortex, and then use the orientation to determine the control area corresponding to the slender body, set any positive electrode in the control area as the e1 electrode, its clockwise positive electrode as the e2 electrode, and its counterclockwise positive electrode as the e3 electrode, and the above three electrodes constitute the control unit. Division and selection of control modes: 1. Low-power excitation mode (mode 1), in this mode, only the electrical parameters at both ends of the e1 electrode are experimental test pulse voltage, pulse width and pulse frequency, and the control module 4 controls the high-voltage AC source 6 to provide energy input for the above electrodes; 2. Positive DC excitation mode (mode 2), the electrical parameters at both ends of the e1 electrode are experimental test pulse voltage, pulse width and pulse frequency, and a positive DC voltage is applied to the e2 or e3 electrode. The control module 4 controls the high-voltage AC source 6 to provide energy input for the e1 electrode, and the control module 4 controls the high-voltage DC source 5 to be the e2 or e3 electrode. 1. Negative DC excitation mode (mode 3), the electrical parameters at both ends of the e1 electrode are the experimental test pulse voltage, pulse width and pulse frequency, the voltage at both ends of the e2 or e3 electrode is a negative DC voltage, the control module 4 controls the high-voltage AC source 6 to provide energy input for the e1 electrode, and the control module 4 controls the high-voltage DC source 5 to provide energy input for the e2 or e3 electrode; 2. Dynamic excitation mode (mode 4), the electrical parameters at both ends of the e1 electrode are the experimental test pulse voltage, pulse width and pulse frequency, and the e2 and e3 electrodes are dynamically selected from the positive and negative DC voltages within a certain threshold. The control module 4 controls the high-voltage AC source 6 to provide energy input for the e1 electrode, and the control module 4 controls the high-voltage DC source 5 to provide energy input for the e2 or e3 electrode.

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

[0014] 1. The present invention provides an asymmetric vortex control method and system for a wide-sector plasma actuator modified with silicon carbide material, which makes up for the shortcomings of asymmetric vortex control of slender rotating bodies in the prior art in terms of low energy consumption and high efficiency. This method can efficiently control the asymmetric vortex appearing on the back of a slender rotating body during high-speed flight, and provides important reference value for the engineering application of asymmetric vortex control of slender rotating bodies.

[0015] 2. The present invention provides an asymmetric vortex control method for a wide-sector plasma actuator modified with silicon carbide material. By selecting a control unit and a control mode, the control of asymmetric vortices in different regions is adapted, covering the entire area of ​​the tip of the slender body, thereby ensuring the stability of the flight of the slender body.

[0016] 3. The present invention discloses an asymmetric vortex control system for a wide-sector plasma actuator modified with silicon carbide material. The wide-sector plasma actuator with material modification greatly improves the control efficiency, and all electrodes are realized through a magnetron sputtering process, thereby reducing manufacturing costs and process complexity.

[0017] 4. The asymmetric vortex control system of a wide-sector plasma actuator modified with silicon carbide material of the present invention realizes feedback control of the vortex state of the current back area of ​​the slender rotating body by connecting the control system, and can adopt different adaptive control modes under variable angle of attack to achieve the optimal asymmetric vortex control effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the structure of the asymmetric vortex control system of the present invention.

[0019] Figure 2 It is a schematic diagram of the structure of the plasma actuator of the present invention.

[0020] Figure 3 It is a schematic flow chart of the asymmetric vortex control method of the slender body of a wide-sector plasma actuator modified with silicon carbide material of the present invention.

[0021] Figure 4 It is a flow chart of a control module in an asymmetric vortex control system of a wide sector plasma actuator slender body modified with silicon carbide material according to the present invention.

[0022] Figure 5 The present invention discloses a plasma actuator jet state diagram and an asymmetric vortex control state diagram in an asymmetric vortex control system of a wide-sector plasma actuator slender body modified with silicon carbide material.

[0023] In the figure: 1.1 / 1.3 flexible pressure-sensitive sensor; 2. Silicon carbide material modified wide-sector plasma actuator structure; 2.1, public 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 invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0025] See also Figure 1 and Figure 2 Some embodiments of the present invention provide a plasma actuator structure for controlling asymmetric vortex in a slender body. Figure 2As shown, it mainly includes a public positive electrode 2.1, a private positive electrode 2.2 / 2.3, a ground electrode 2.4 and a blocking medium 2.5. The public positive electrode 2.1, the private positive electrode 2.2 / 2.3 and a ground electrode 2.4 are made of copper, and the molding method is magnetron sputtering. The sputtering time is 48 hours. The configuration of the public positive electrode 2.1 and the private positive electrode 2.2 / 2.3 is a circular sector, and the circular sector angle is 240°. The blocking medium The material 2.5 is polyimide and located between the common positive electrode 2.1, the private positive electrode 2.2 / 2.3 and the ground electrode 2.4. The ground electrode 2.4 is in the shape of a circular sector with an angle of 360°. The position corresponds to the inner circle of each positive electrode. The area between the common positive electrode 2.1 and the private positive electrode 2.2 / 2.3 is the material modification area 2.6. The modified material is silicon carbide. The film formation method is magnetron sputtering and the sputtering time is 48 hours.

[0026] It should be noted that the number of the public positive electrodes 2.1 and the private positive electrodes 2.2 and 2.3 of the plasma actuator structure are both 10, and the arrangement is in the downstream direction, and the number of the ground electrodes 2.4 corresponds to the number and position of the positive electrodes. The plasma actuator structure thus constructed is a wide-sector plasma actuator structure 2 modified by silicon carbide material.

[0027] In some embodiments, the present invention also provides an asymmetric vortex system. The system is composed of Figure 1 As shown, the system mainly consists of 6 parts: a flexible pressure-sensitive sensor 1, a silicon carbide material modified wide-sector plasma actuator structure 2, a slender body tip top 3, a control module 4, a high-voltage DC source 5, and a high-voltage AC source 6. The flexible pressure-sensitive sensor 1 is an array-type flexible pressure-sensitive sensor 1, which is made of polyimide and has a model of RX-M0808M. The array-type flexible pressure-sensitive sensor 1 is arranged at the top 3.1 and the tail 3.3 of the slender body tip top 3 to collect surface pressure data in real time. The flexible pressure-sensitive sensor 1 is electrically connected to 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 public positive electrode 2.1, private positive electrodes 2.2, 2.3 and ground electrode 2.4 thereon are electrically connected to the control module 4 respectively; the slender body tip 3 is made of quickly replaceable quartz glass, and a hollow channel is provided inside thereof, and the hollow channel runs 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 slender bodies of different specifications.

[0028] The working principle of the closed-loop method for controlling the asymmetric vortex of a slender body is as follows: Figure 3As shown, the array-type flexible pressure-sensitive sensor installed on the top 3 of the slender body tip detects the pressure changes caused by the change of the angle of attack or the change of the environment in real time, and sends these data to the asymmetric vortex control module for online monitoring and control. When the control module detects that an asymmetric vortex is generated in the leeward area by analyzing the sensor data, the following contents are executed:

[0029] The data S of the flexible pressure-sensitive sensor 1 indicates the eddy current state, then

[0030]

[0031] When S=0, it means that the current flow field on the surface of the slender body is in a normal state. When S=1, it means that the current surface of the slender body is in an asymmetric vortex state. The asymmetric vortex position R(X / D,θ) can be determined according to the relevant positioning method. 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] An asymmetric vortex control system method using a circular sector plasma exciter structure 2 modified by silicon carbide material includes three positive electrodes and a ground electrode, and the electrode number e is determined by calculating the relative positions of the three positive electrodes and the asymmetric vortex position R:

[0033]

[0034] in,

[0035]

[0036] Define the control function in different control modes as V(e n ,k m ), where e n Defined as the electrode number, n ranges from (1, 2, 3), k m Defined as control mode, m control mode is divided into: low power excitation mode (m = a); positive DC excitation mode (m = b); negative DC excitation mode (m = c) and dynamic excitation mode (m = d). Then:

[0037]

[0038] First, the orientation of the eddy current is determined by the positioning method. Then, the control area corresponding to the orientation is used to set any positive electrode in the control area as the e1 electrode, its clockwise positive electrode as the e2 electrode, and its counterclockwise positive electrode as the e3 electrode. Finally, the silicon carbide material modified wide-sector plasma exciter 3 installed on the top of 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 the e1 electrode is raised to the excitation voltage (experimental experience voltage: 14kV). According to the positioning data, if the asymmetric eddy current is controlled, the system will maintain the current excitation state.

[0040]

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

[0042]

[0043] If the asymmetric eddy current is still not controlled, the system switches to the negative DC excitation mode (mode 3). At this time, the voltage across the e1 electrode is still the experimental experience voltage, while the voltage across the e2 or e3 electrode is a negative DC voltage of the experimental experience voltage.

[0044]

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

[0046]

[0047] See also Figure 4 , a control system for asymmetric vortices of the present invention, an array of flexible pressure-sensitive sensors 1 are arranged on the tip 3 of the slender body, and these sensors are responsible for capturing pressure data. These data are processed by a digital-to-analog converter and compared with the pressure threshold in historical experience. Once it is detected that the data meets the characteristics of the asymmetric vortex in the leeward area, the system transmits the data to the signal acquisition card. Then, the closed-loop control method will screen the current motion state of the slender body and select the control mode, and adjust the voltage and select the corresponding electrode for precise control by driving the control circuit. If the initial control attempt fails, the system will start the process again to try control; if control is successfully achieved, the system will maintain 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 utilize the asymmetric vortex control effect achieved by the above system.

[0048] The experimental method and system of the present invention have the following advantages: first, it fills the current gap in the integration of the tip of the slender rotating body model and the plasma actuator, and its characteristics of rapid replacement and multi-excitation mode are helpful to promote the research and development and application of various types of slender rotating bodies; second, we propose a method based on material modification to improve the performance of wide-sector plasma actuators, which improves the speed and volume force of the induced jet by reducing the residual charge in the discharge area, thereby improving the control efficiency; third, the present invention also introduces a new wide-sector plasma actuator configuration, which is suitable for controlling the asymmetric vortex of a slender body. This configuration solves the limitations of the traditional configuration by circumferentially covering the tip of the slender body with three positive electrodes; in addition, we also propose a new method by which a wide-sector plasma actuator is used to control the asymmetric vortex. This method is flexible and convenient, and has high universality and high control efficiency; finally, compared with the traditional configuration, the control components of the present invention have less interference with the flow field of the slender body, higher efficiency in controlling the asymmetric vortex, and higher reliability.

Claims

1. A plasma actuator structure, characterized in that: The invention comprises a common positive electrode (2.1), a private positive electrode (2.2, 2.3), a ground electrode (2.4) and a blocking medium (2.5); the common positive electrode (2.1), the private positive electrode (2.2, 2.3) and the ground electrode (2.4) are made of copper; the common positive electrode (2.1) and the private positive electrode (2.2, 2.3) are in the shape of a circular sector; the blocking medium (2.5) is located between the common positive electrode (2.1), the private positive electrode (2.2, 2.3) and the ground electrode (2.4) and is made of polyimide; the position of the ground electrode (2.4) corresponds to the inner circle of each positive electrode; the area between the common positive electrode (2.1) and the private positive electrode (2.2, 2.3) is a material modification area (2.6).

2. A plasma actuator structure according to claim 1, characterized in that: The number of the public positive electrodes (2.1) and the private positive electrodes (2.2, 2.3) of the plasma actuator structure is 10 each, and the number of the ground electrodes (2.4) corresponds to the number and position of the positive electrodes. The modified material of the modified area (2.6) is silicon carbide material. The plasma actuator structure thus constructed is a wide-sector plasma actuator structure (2) modified with silicon carbide material.

3. An asymmetric vortex control system, using the wide sector plasma actuator structure (2) modified by silicon carbide material as claimed in claim 2, characterized in that: The invention also comprises an array-type flexible pressure-sensitive sensor (1), a slender body tip (3), a control module (4), and a high-voltage direct current source (5) and a high-voltage alternating current source (6) electrically connected to the control module (4) respectively; the flexible pressure-sensitive sensor (1) is arranged at the top (3.1) and the tail (3.3) of the slender body tip (3), and is electrically connected to the control module (4); the wide-sector plasma exciter structure (2) modified by silicon carbide material is arranged at the middle (3.2) of the slender body tip (3), and the public positive electrode (2.1), the private positive electrode (2.2, 2.3) and the ground electrode (2.4) thereon are electrically connected to the control module (4) respectively; the slender body tip (3) is provided with a hollow channel inside, the hollow channel passes through the connecting portion (3.4) on the slender body tip (3), and the connecting portion (3.4) is provided with a connecting portion groove (3.5) to adapt to slender bodies of different specifications.

4. An asymmetric vortex control method, based on the asymmetric vortex control system according to claim 3, characterized in that: An array-type flexible pressure-sensitive sensor (1) is used to capture pressure data at the top of the slender body tip (3) to represent the eddy current state, and the use of a common positive electrode (2.1), two private positive electrodes (2.2, 2.3) and a high-voltage direct current source (5) and a high-voltage alternating current source (6) is achieved by judging the eddy current state.

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