A large-scale pulsed arc plasma actuator matrix with real-time variable formation

Abstract

A large-scale pulsed arc plasma exciter matrix with real-time variable formation is described. Based on a pulsed surface arc plasma exciter, individual arc plasma exciters are expanded in both row and column directions to form an arc plasma exciter matrix. A power supply circuit is provided, with each exciter having its own independent power supply unit. A method for achieving real-time variable control of the exciter matrix formation using a shift register is also provided. This invention facilitates expansion of the number of discharge circuits, with no electrical connections between the exciters, resulting in no interference and strong robustness. The discharge circuit eliminates reliance on a high-voltage trigger power supply, enabling dozens or hundreds of pulsed arc discharge plasma excitations. By introducing a shift register circuit, this matrix achieves real-time variable excitation formation, significantly improving the arc plasma exciter matrix's adaptability to complex and changing flight conditions and potentially achieving higher flow control efficiency.

Description

Technical Field

[0001] The present invention relates to the field of active flow control, and in particular to a large-scale pulse arc plasma exciter matrix with real-time variable formation. Background Art

[0002] In aviation, pulsed surface arc plasma actuators (PAPs) are commonly used to control supersonic shock wave flows. These actuators offer the advantages of fast response and high excitation intensity. They can quickly inject a large amount of thermal energy into the flow field through arc heating. This heat blockage alters the original shock wave structure or promotes momentum mixing within the boundary layer, thereby suppressing flow separation and reducing shock wave intensity. Structurally, these actuators consist of a pair of tungsten needle electrodes (anode and cathode) and an insulating substrate. Limited by the output voltage of existing high-voltage pulse power supplies (10kV-20kV), the typical discharge spacing is 2-5mm. Therefore, in practical engineering applications, achieving flow control in full-scale inlets (typically 500mm wide) for high-speed aircraft requires a matrix of dozens or even hundreds of PAPs to achieve a wider range of flow field manipulation capabilities. On the one hand, the increasing number of PAPs poses significant challenges to power supply and circuit design. According to public literature, the number of arc plasma exciter discharge circuits that can be achieved by a single power supply is 31 (【1】Zhang, Z.-B., Wu, Y., Jia, M., Song, H.-M., Sun, Z.-Z., & Li, Y.-H. (2017). Modeling and optimization of the multichannel spark discharge. Chinese Physics B, 26(6). doi: 10.1088 / 1674-1056 / 26 / 6 / 065204). On the other hand, due to the variable flight state of the aircraft, the formation of the large-scale arc plasma exciter matrix is ​​required to be able to perform real-time intelligent adaptive adjustment according to the incoming flow state in order to achieve the best flow control effect.In the existing research on supersonic shock wave control, the circuit connection mode of the arc plasma excitation matrix is ​​mostly the end-to-end connection form of "anode-cathode-anode-cathode". All actuators can only be turned on or off at the same time, and it is impossible to achieve real-time rapid adjustment of the array by selective opening and closing (【2】Zhang, Z., Zhang, X., Wu, Y., Jia, M., Jin, D., Sun, Z., & Li, Y. (2020). Experimental research on the shock wave control based on one power supply driven plasma synthetic jet actuator array. ActaAstronautica, 171, 359-368. doi: 10.1016 / j.actaastro.2020.03.035. 【3】Tang, M., Wu, Y., Guo, S., Sun, Z., & Luo, Z. (2020). Effect of the streamwise pulsed arc discharge array on shock wave / boundary layer interaction control. Physics of Fluids, 32(7).doi:10.1063 / 5.0011040). Summary of the Invention

[0003] To address the problems existing in the prior art, the present invention proposes a large-scale pulsed arc plasma exciter matrix with real-time variable formation. The matrix is ​​based on a pulsed surface arc plasma exciter, which consists of an insulating substrate, an anode, and a cathode. The anode and cathode are needle-shaped and vertically inserted from the back to the front of the insulating substrate. The tops of the anode and cathode are flush with the upper surface of the insulating substrate, and the top and bottom of the anode and cathode are exposed. The area below the insulating plate is sealed. The electrode gap between the anode and cathode is determined by the breakdown voltage of the external power supply and the ambient air pressure. The matrix is ​​characterized by expanding a single arc plasma exciter in both row and column directions to obtain an arc plasma exciter matrix.

[0004] In one embodiment of the present invention,

[0005] The electrode gap between the anode and cathode of the pulsed surface arc plasma exciter is 0.5-5 mm; the thickness of the insulating substrate plate is 3 mm-20 mm;

[0006] The arrangement spacing of the rows and columns of the arc plasma exciter matrix ranges from 5 to 30 mm;

[0007] The exciters of the matrix are numbered 1, 2, ..., n in order from left to right and from top to bottom.

[0008] In a specific embodiment of the present invention,

[0009] The electrode gap between the anode and cathode of the pulsed surface arc plasma exciter is 2 mm; the thickness of the insulating substrate plate is 10 mm;

[0010] The arrangement spacing of the rows and columns of the arc plasma exciter matrix is ​​in the range of 10 mm;

[0011] The layout of the arc plasma exciter matrix is ​​a square array, a triangle array or a diamond array.

[0012] Provided is a power supply circuit for a large-scale pulse arc plasma exciter matrix with real-time variable formation, which supplies power to the large-scale pulse arc plasma exciter matrix with real-time variable formation; wherein,

[0013] Use G1, G2, ..., G n Refers to exciter 1, 2, ..., n; each exciter has its own independent power supply unit, each power supply unit has the same structure, and each exciter is connected to each other through a diode Da i Isolation, i = 1, 2, ..., n, the discharge is turned on and off by the trigger signal Q i control;

[0014] The power supply unit of the exciter G2 is specifically as follows: the inductor L, the second isolation diode Da2, the second capacitor discharge diode Db2, and the second exciter G2 are connected in series in sequence between the output terminal of the DC power supply DC and the ground according to the conventional connection method; the second energy storage capacitor C2 is connected between the node between the second isolation diode Da2 and the second capacitor discharge diode Db2 and the ground; the gate of the second switch tube S2 inputs the trigger signal Q2, its drain is connected to the node between the second isolation diode Da2 and the second capacitor discharge diode Db2, and its source is connected to the positive terminal of the primary coil of the second transformer T2; the negative terminal of the second trigger discharge diode Dc2 is connected to the node between the second capacitor discharge diode Db2 and the second exciter G2, and its positive terminal is connected to the positive terminal of the secondary coil of the second transformer T2; the negative terminal of the primary coil and the negative terminal of the secondary coil of the second transformer T2 are grounded.

[0015] In another embodiment of the present invention, the second switch tube S2 is a transistor, a metal oxide semiconductor field effect tube MOSFET or other power electronic switches.

[0016] The specific working principle of the power supply circuit of the above-mentioned large-scale pulse arc plasma exciter matrix with real-time variable formation is as follows:

[0017] (1) The DC power supply DC, the inductor L, the first isolation diode Da1 and the first energy storage capacitor C1 form a voltage doubling charging circuit; after the voltage doubling charging is completed, the voltage across the first energy storage capacitor C1 is twice the output voltage U0 of the DC power supply DC; to ensure that the gas gap does not automatically break down during the charging process, the output voltage U0 of the DC power supply DC should be less than the breakdown voltage U across the first exciter G1. b Half of the maximum output power of the DC power supply P max The output voltage U0 of the DC power supply, the total number of actuators n, and the maximum operating frequency F of the actuator are max And the first energy storage capacitor C1 is determined by the following formula:

[0018] P max =2nF max C1U0 2 (1)

[0019] During the charging process, the inductor L plays the role of limiting the charging current and storing electrical energy; since the maximum output current I max =P max / U0, so the minimum inductance value of the inductor is L min By solving the second-order differential equation of the voltage-doubling charging circuit, we can obtain:

[0020]

[0021] When the inductance value is too small, that is, L <L min When the inductance is too high, the charging current of the circuit will exceed the maximum output current of the DC power supply, causing the DC power supply DC output to be overloaded; on the contrary, when the inductance value is too large, it will cause the charging time to be too long, affecting the maximum discharge operating frequency of the exciter; the withstand voltage of the first diode Da1 should be higher than twice the DC power supply DC output voltage, and the rated current should be greater than the maximum output current I of the DC power supply DC. max The withstand voltage of the first energy storage capacitor C1 should be greater than twice the DC power supply DC output voltage;

[0022] (2) The first energy storage capacitor C1, the first switch tube S1 and the first transformer T1 form a pulse boost circuit; when the first trigger signal Q1 is at a high level, the first switch tube S1 is quickly turned on, and the voltage across the first energy storage capacitor C1 is quickly loaded on the primary coil of the first pulse transformer T1; due to electromagnetic induction, a high-voltage pulse will be generated on the secondary coil of the first pulse transformer T1, and its amplitude is determined by the turns ratio k of the first pulse transformer T1; the switching time of the first switch tube S1 can reach the order of 0, and the withstand voltage value is more than twice the energy storage capacitor voltage;

[0023] (3) The first transformer T1, the first diode Dc1, and the first exciter G1 form a trigger discharge circuit; the high-voltage pulse generated by the secondary coil of the first pulse transformer T1 passes through the first diode Dc1 and is applied to the first exciter G1; when the voltage exceeds the breakdown voltage of the gas gap, a discharge plasma channel is generated between the two electrodes of the first exciter G1; since the output current of the secondary coil is very small, the arc discharge at this time is relatively weak, belonging to a high-voltage, low-current triggered discharge; after the triggered discharge is formed, the first switch tube S1 is closed;

[0024] (4) The first energy storage capacitor C1, the first diode Db1 and the first exciter G1 form a capacitor discharge circuit; before the high-voltage triggered discharge, since the voltage across the first energy storage capacitor C1 is less than the gas gap breakdown voltage of the first exciter G1, no current flows through the circuit; during the high-voltage triggered discharge, the gas gap is broken down, forming a conductive plasma channel between the anode and the cathode; therefore, a large amount of electrical energy stored in the first energy storage capacitor C1 is rapidly injected into the gas gap between the anode and the cathode through the first diode Db1, forming a strong arc discharge; when the electrical energy in the energy storage capacitor is completely released, the discharge channel is extinguished, and a working cycle ends.

[0025] In yet another embodiment of the present invention,

[0026] Choose a DC power supply below 1kV;

[0027] The capacitance value of the second energy storage capacitor C2 ranges from 0.1uF to 10uF;

[0028] In order to be able to break through the gas gap of 2-5 mm, the amplitude range of the high voltage pulse is 10-30 kV; the turn ratio value of the first pulse transformer T1 is 5-20.

[0029] In another specific embodiment of the present invention, the capacitance value of the second energy storage capacitor C2 is 1uF;

[0030] In order to penetrate the gas gap of 2-5 mm, the amplitude of the high-voltage pulse is 20 kV; the turn ratio of the first pulse transformer T1 is 10.

[0031] The present invention also provides a method for realizing real-time variable control of an actuator matrix array using a shift register, which is based on the large-scale pulse arc plasma actuator matrix with real-time variable array, wherein:

[0032] The control chip can provide three high-speed digital signal output ports DO1, DO2, and DO3;

[0033] A real-time variable control circuit is realized by using m shift registers, wherein the number of registers m satisfies m≥n / 8; each shift register has a plurality of bit output ports; the register also includes the following ports: a signal input port DS (1), a power supply port VCC (10), a ground port GND (11), a clear port CLR (12), and a clock signal port CLK (13);

[0034] Multiple groups of registers are connected end to end to ensure that the sum of the output bits of all registers is greater than the total number of trigger signal channels required by the exciter matrix;

[0035] Power the shift register and control chip; the negative pole of the power supply is connected to the GND port of each shift register module; the positive pole of the power supply is directly connected to the VCC port of each shift register module, and then connected to the CLR port of each shift register module through a NOT gate; the DO1 port of the control chip outputs the clock signal, which is connected to the clock port CLK of each shift register; the DO3 port of the control chip is the output enable signal ENB, which is used as the actual trigger signal Q of the exciter discharge circuit after the logic AND operation with the output signal of each shift register. i Output, i = 1, 2, ..., n; DO2 port is connected to the signal input port DS of shift register 1, the highest bit output signal Q8 of shift register 1 is connected to the signal input port DS of shift register 2, and so on. By connecting the highest bit output signal of the previous shift register to the signal input port DS of the next shift register, all shift registers are connected in series.

[0036] In yet another embodiment of the present invention,

[0037] A complete working cycle of the variable array plasma actuator matrix includes four stages: the excitation array setting stage, the high-voltage trigger discharge stage, the capacitor discharge stage, and the capacitor charging stage; the details are as follows:

[0038] (1) Incentive formation setting stage, 0≤t <t A ;

[0039] The control chip sets the ENB enable signal of the DO1 channel to a low level to ensure that there will be no discharge trigger instruction Q iOutput from the AND gate; DO3 channel sends a series of clock signals CLK, and DO2 channel outputs the discharge information of each actuator in the arc plasma actuator matrix in the form of high and low levels in reverse order to the DS port of shift register 1; since the shift register shifts at the rising edge of the clock signal, the total number of rising edges of the clock signal should be equal to the sum of the number of bits of all shift registers; when the clock signal CLK ends, the shift register completes the conversion from serial array input to parallel array output, and the high and low levels of each output port represent the working information of the corresponding actuator;

[0040] (2) High voltage trigger stage, t A ≤t <t B ;

[0041] The DO1 channel of the control chip sets the enable signal ENB to a high level; the exciter matrix trigger signal stored in the shift register passes through the AND gate and is loaded into the switch tube S at the same time. i Each trigger channel Q i On, i=1,2,…,n; when Q i =1, the corresponding switch tube S i Open, exciter G i The voltage across the two ends is U d Rapidly rise from the capacitor voltage to the breakdown voltage, forming a high-voltage trigger discharge channel in the gas gap; on the contrary, if Q i = 0, the exciter G i When the discharge trigger is completed, the control chip sets the ENB enable signal to a low level, and the switch tube S i In the closed state, preparing for the next step of capacitor charging;

[0042] (3) Capacitor discharge stage, t B ≤t <t C ;

[0043] For the actuator G that has triggered discharge i , energy storage capacitor C i The stored electrical energy is rapidly injected into the gas gap to form a pulsed arc plasma discharge of a specified formation; in this process, the discharge current I d First it increases and then decreases; when the capacitor energy is exhausted, the arc goes out and the discharge current becomes 0;

[0044] (4) Capacitor charging stage, t C ≤t <T0;

[0045] The DC power supply DC passes through the inductor L and the diode Da i , for the energy storage capacitor C i Charging; the voltage U across the exciter dKeeping consistent with the capacitor voltage, both start from zero and gradually increase to twice the DC power supply output voltage.

[0046] The advantages of the present invention are as follows:

[0047] 1. Traditional arc plasma actuator matrices can only be turned on and off simultaneously, unable to change formations, making them poorly adaptable to complex and changing flight conditions. The pulsed arc plasma actuator matrix of the present invention allows each channel to be independently controlled, enabling the overall matrix to be capable of real-time variable formations, making it highly adaptable to complex flight environments.

[0048] 2. Traditional single-power-driven arc plasma actuator matrices are limited to approximately 30 simultaneous discharges due to energy loss during the "relay triggering" process. The present invention theoretically allows for unlimited number of arc plasma actuators within the matrix, enabling large-scale actuator matrices with hundreds of actuators, meeting the control requirements of large-scale aviation flows.

[0049] 3. The arc plasma exciter matrix of the present invention only requires a medium voltage DC source during operation, and does not require an additional high voltage pulse trigger power supply. The overall structure of the power supply system is simple and economical.

[0050] 4. The arc plasma exciter matrix of the present invention has good scalability. When increasing the number of exciters, it is only necessary to increase the number of power supply units and the number of output channels of the shift register accordingly, without the need to re-topologically design and expand the original power supply circuit.

[0051] 5. The real-time variable formation control of the large-scale plasma actuator matrix in the present invention can be realized by occupying only three output ports of the controller chip, and has low requirements for the hardware system. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 (a) shows the structure of a single arc plasma exciter; Figure 1 (b) shows the surface arc plasma exciter matrix;

[0053] Figure 2 Shows the power supply circuit of the arc plasma exciter matrix;

[0054] Figure 3 The invention shows that the real-time variable control of the actuator matrix formation can be realized by using a shift register;

[0055] Figure 4 Shows the timing changes of each signal within a complete working cycle. DETAILED DESCRIPTION

[0056] Figure 1(a) shows a schematic diagram of a typical pulsed surface arc plasma exciter structure. The exciter consists of an insulating substrate, an anode, and a cathode. The anode and cathode are needle-shaped and inserted vertically from the back to the front of the insulating substrate. The tops of the anode and cathode are flush with the upper surface of the insulating substrate to ensure that the geometric protrusions do not adversely interfere with external airflow. The top and bottom of the anode and cathode are exposed for welding high-voltage wires. Both the anode and cathode are made of conductive metal materials, preferably high-temperature resistant tungsten needles (pure tungsten or tungsten alloy), but copper or iron with good conductivity can also be used. The electrode gap between the anode and cathode is determined by the breakdown voltage of the external power supply and the ambient pressure, and under typical conditions ranges from 0.5 to 5 mm (preferably 2 mm). The insulating substrate is made of a high-voltage resistant insulating material, preferably ceramic, but can also be made of polyimide sheet, PEEK sheet, or nylon. The insulating substrate serves to secure the anode and cathode and provides insulation. The thickness of the sheet needs to match the flow control experimental model and is not limited here. Under typical conditions, it is approximately 3 mm to 20 mm (preferably 10 mm). When the voltage applied between the two electrodes is higher than the breakdown voltage of the gas gap, an arc discharge plasma will be formed between the anode and cathode on the upper surface of the insulating substrate. At the same time, in order to prevent the cathode and anode from creeping under the insulating plate, silicone, potting glue or other similar glues are required to seal the area under the insulating plate. The choice of insulating glue and how to seal it are common sense for those skilled in the art, so the present invention does not include any specific details. Figure 1 (a) is marked.

[0057] Will Figure 1 The single arc plasma exciter in (a) is expanded along the row and column directions to obtain Figure 1 (b) The arc plasma actuator matrix shown. Figure 1 In the embodiment shown in (b), the arc plasma actuator matrix consists of 8 rows (R-1, R-2, ..., R-8) and 4 columns (C-1, C-2, C-3, C-4), for a total of 32 actuators. In actual engineering applications, the matrix can contain any number of rows and columns of plasma actuators. The arrangement spacing of rows and columns needs to be analyzed based on the flow field to be controlled, and the typical range is 5-30mm. The larger the spacing, the fewer the total number of actuators required for the same flow field to be controlled. However, excessive spacing between actuators will cause problems with the control efficiency being unable to connect left and right and relay front and back. Therefore, after comprehensive consideration, it is recommended that the spacing between rows and columns in the actuator matrix be 10mm. Figure 1 The layout of the actuator matrix in (b) is a square array, which can be adaptively modified to a triangular array or a diamond array for three-dimensional flow control applications. Figure 1The exciters in the matrix shown in (b) are numbered 1, 2, ..., n in order from left to right and from top to bottom. In the above embodiment, n=32.

[0058] Figure 2 This is the power supply circuit of the pulse arc plasma exciter matrix. From the perspective of circuit load, each arc plasma exciter is essentially a gas gap load, so the sharp discharge symbols G1, G2, ..., G n Refers to exciter 1, 2, ..., n. Each exciter has its own independent power supply unit, each power supply unit has the same structure, and each exciter is connected to each other through a diode Da i (i=1,2,…,n) for isolation, the discharge is turned on and off by the trigger signal Q i (i=1,2,…,n) control.

[0059] The power supply unit structure of the exciter G2 is described below using the power supply unit of the exciter G2 as an example. The inductor L, the second isolation diode Da2, the second capacitor discharge diode Db2, and the second exciter G2 are connected in series, in a conventional manner, between the output terminal of the DC power supply DC and ground. The second energy storage capacitor C2 is connected between the node between the second isolation diode Da2 and the second capacitor discharge diode Db2 and ground. The second switch S2 can be a transistor, a metal oxide semiconductor field effect transistor (MOSFET), or other power electronic switch. For ease of control, a voltage-controlled MOSFET is preferred. The gate of the second switch S2 is used to input the trigger signal Q2. Its drain is connected to the node between the second isolation diode Da2 and the second capacitor discharge diode Db2, and its source is connected to the positive terminal of the primary winding of the second transformer T2. The negative terminal of the second trigger discharge diode Dc2 is connected to the node between the second capacitor discharge diode Db2 and the exciter G2, and its positive terminal is connected to the positive terminal of the secondary winding of the second transformer T2. The negative terminal of the primary winding and the negative terminal of the secondary winding of the second transformer T2 are grounded.

[0060] The specific working principle of the power supply circuit is described below in detail by taking the exciter G1 as an example.

[0061] (1) The DC power supply DC, the inductor L, the first isolation diode Da1 and the first energy storage capacitor C1 form a voltage doubling charging circuit. Unlike ordinary RC charging circuits, after the voltage doubling charging is completed, the voltage across the first energy storage capacitor C1 is twice the output voltage U0 of the DC power supply DC. Therefore, in order to ensure that the gas gap does not automatically break down during the charging process, the output voltage U0 of the DC power supply DC should be less than the breakdown voltage U across the first exciter G1. bTaking the 2mm actuator electrode spacing under atmospheric pressure as an example, the theoretical breakdown voltage is 6kV, and the output range of the DC power supply can be selected to be 0-3kV (ensuring a double margin). In the present invention, from the perspective of technical maturity and power-to-weight ratio, a DC power supply below 1kV is preferred. The maximum output power P of the DC power supply is max The output voltage U0 of the DC power supply, the total number of actuators n, and the maximum operating frequency F of the actuator are max And the first energy storage capacitor C1 is determined by the following formula:

[0062] P max =2nF max C1U0 2 (1)

[0063] The derivation of this formula is not difficult for those skilled in the art, so it will not be described in detail. Once the above parameters are determined, the DC power supply can be selected. During the charging process, the inductor L plays the role of limiting the charging current and storing electrical energy. Since the maximum output current I max =P max / U0, so the minimum inductance value of the inductor is L min It can be obtained by solving the second-order differential equation of the voltage doubler charging circuit:

[0064]

[0065] When the inductance value is too small (i.e. L <L min ), the charging current of the circuit will exceed the maximum output current of the DC power supply, causing the DC power supply DC output to overload. On the contrary, when the inductance value is too large, it will cause the charging time to be too long, affecting the maximum discharge operating frequency of the exciter. The main function of the first diode Da1 is to prevent the electric energy stored in the first energy storage capacitor C1 from flowing back to the DC power supply DC. Therefore, its withstand voltage should be higher than twice the DC power supply DC output voltage, and the rated current should be greater than the maximum output current I of the DC power supply DC. max The withstand voltage of the first energy storage capacitor C1 should also be greater than twice the DC power supply DC output voltage, and the typical capacitance value range is 0.1uF-10uF, preferably 1uF.

[0066] (2) The first energy storage capacitor C1, the first switch tube S1 and the first transformer T1 form a pulse boost circuit, the main function of which is to generate a high-voltage pulse. Specifically, when the first trigger signal Q1 is at a high level, the first switch tube S1 is quickly turned on, and the voltage across the first energy storage capacitor C1 is quickly loaded on the primary coil of the first pulse transformer T1. Due to electromagnetic induction, a high-voltage pulse will be generated on the secondary coil of the first pulse transformer T1, and its amplitude is determined by the turns ratio k of the first pulse transformer T1. Under typical conditions, in order to be able to break through a gas gap of 2-5mm, the amplitude range of the high-voltage pulse is 10-30kV, preferably 20kV. Correspondingly, the typical value of the turns ratio of the first pulse transformer T1 is 5-20, and the preferred value is 10. The first switch tube S1 can be a MOSFET, an IGBT or other power electronic switching device, as long as the switching time can reach the order of O (1us) and the withstand voltage value is more than twice the voltage of the energy storage capacitor.

[0067] (3) The first transformer T1, the first diode Dc1, and the first exciter G1 form a trigger discharge circuit. The high-voltage pulse generated by the secondary coil of the first pulse transformer T1 is applied to the first exciter G1 after passing through the first diode Dc1. When the voltage exceeds the breakdown voltage of the gas gap, a discharge plasma channel is generated between the two electrodes of the first exciter G1. Since the output current of the secondary coil is very small, the arc discharge at this time is relatively weak (the current is in the mA level), which is a high-voltage, low-current triggered discharge. After the trigger discharge is formed, the first switch tube S1 can be closed.

[0068] (4) The first energy storage capacitor C1, the first diode Db1 and the first exciter G1 form a capacitor discharge circuit. Before the high-voltage triggered discharge, since the voltage across the first energy storage capacitor C1 is less than the gas gap breakdown voltage of the first exciter G1, no current flows through the circuit. During the high-voltage triggered discharge process, the gas gap is broken down, forming a conductive plasma channel between the anode and the cathode. Therefore, the large amount of electrical energy stored in the first energy storage capacitor C1 can be quickly injected into the gas gap between the anode and the cathode through the first diode Db1, forming a strong arc discharge, and the typical discharge current can reach hundreds of amperes to thousands of amperes. When the electrical energy inside the energy storage capacitor is released, the discharge channel is extinguished, and a working cycle ends.

[0069] From the above description, it can be seen that in each discharge cycle, the pulse arc plasma exciter G i (i=1,2,…,n) Whether the work is completed is determined by the corresponding trigger signal Q i (i=1,2,…,n) control. Therefore, to realize real-time variable formation, it is only necessary to control the trigger signal Q in each discharge cycle. i You can set the high and low levels respectively.

[0070] Figure 3 A method for implementing real-time variable control of the actuator matrix array using shift registers is presented. The control chip can be a single-chip microcomputer, a computer equipped with a high-speed data acquisition card, or an FPGA, as long as it can provide three high-speed output ports (DO1, DO2, DO3) of digital signals. In view of the requirements of supersonic flow control, the refresh frequency of the digital signal output port is required to be above 10MHz. The real-time variable control circuit is implemented using m shift registers, where the number of registers m should meet the following conditions: m≥n / 8. Each shift register has a number of output ports (8 bits in the figure, Q a ,Q b ,…,Q h ). In addition, the register also includes the following ports: signal input port DS (numbered 1 in the figure), power supply port VCC (numbered 10), ground port GND (numbered 11), clear port CLR (numbered 12), clock signal port CLK (numbered 13). In order to achieve real-time adjustment of the trigger signal of a large-scale arc exciter matrix, multiple groups of registers are connected end to end. In similar implementation cases, the output bit number of a single shift register can also be 4 bits, 16 bits or other bits, as long as the sum of the output bit numbers of all registers is greater than the total number of trigger signal channels required by the exciter matrix. In order to avoid the influence of strong electromagnetic interference during arc discharge Figure 3 The trigger circuit in the chip works, and the battery BT is used to power the shift register and the control chip. The power supply port of the control chip is not shown in the figure, and the power supply connection method is well known to people in this field. The negative pole of the battery is connected to the GND port of each shift register module. After the positive pole of the battery is directly connected to the VCC port of each shift register module, it is connected to the CLR port of each shift register module through a NOT gate to ensure that the output signal of the shift register is low after an accidental power failure. The DO1 port of the control chip outputs a clock signal, which is connected to the clock port CLK of each shift register. The DO3 port of the control chip is the output enable signal ENB. This signal and the output signal of each shift register are logically ANDed together to serve as the actual trigger signal Q of the exciter discharge circuit. i (i=1,2,…,n) output. DO2 port is connected to the signal input port DS of shift register 1, and the highest bit output signal Q8 of shift register 1 is connected to the signal input port DS of shift register 2. And so on. By connecting the highest bit output signal of the previous shift register to the signal input port DS of the next shift register, all shift registers are connected in series.

[0071] like Figure 4As shown, a complete working cycle of the variable array plasma actuator matrix includes four stages: the excitation array setting stage, the high voltage trigger discharge stage, the capacitor discharge stage and the capacitor charging stage.

[0072] (1) Incentive formation setting stage (0≤t <t A ). First, the control chip sets the ENB enable signal of the DO1 channel to a low level to ensure that there will be no discharge trigger instruction Q i Output from the AND gate. Subsequently, the DO3 channel sends out a series of clock signals CLK, and at the same time, the DO2 channel outputs the discharge or not information (i.e., formation) of each exciter in the arc plasma exciter matrix in the form of high and low levels in reverse serial order to the DS port of the shift register 1. Since the shift of the shift register occurs on the rising edge of the clock signal, the total number of rising edges of the clock signal should be equal to the sum of the number of bits of all shift registers (8m). When the clock signal CLK ends, the shift register completes the conversion from serial formation input to parallel formation output, and the high and low levels of each output port represent the working or not information of the corresponding exciter. Figure 4 Taking the first cycle in the example, the signal input to the DS port of each shift register is always high, so the excitation array is set to "full open array". The total time of the excitation array setting is determined by the clock frequency and the total number of bits of all shift registers. Figure 1 Taking the excitation matrix (32 exciters) in (b) as an example, when the clock frequency is 10 MHz, it only takes 3.2 μs to complete the setting of the exciter matrix array.

[0073] (2) High voltage trigger stage (t A ≤t <t B ). In this stage, the DO1 channel of the control chip sets the enable signal ENB to a high level. The exciter matrix trigger signal stored in the shift register passes through the AND gate and is loaded into the switch tube S at the same time. i Each trigger channel Q i (i=1,2,…,n). When Q i =1, the corresponding switch tube S i Open, exciter G i The voltage across the two ends is U d Rapidly rise from the capacitor voltage to the breakdown voltage, forming a high-voltage trigger discharge channel in the gas gap. On the contrary, if Q i = 0, the exciter G i When the discharge trigger is completed, the control chip sets the ENB enable signal to a low level, and the switch tube S i In the closed state, preparing for the next step of capacitor charging.

[0074] (3) Capacitor discharge stage (t B ≤t <tC )。At this stage, for the actuator G that has undergone trigger discharge i , the energy storage capacitor C i quickly injects the stored electrical energy into the gas gap, forming a pulsed arc plasma discharge in a specified formation. During this process, the discharge current I d first increases and then decreases. When the capacitor's electrical energy is exhausted, the arc extinguishes and the discharge current becomes 0.

[0075] (4) Capacitor charging stage (t C ≤ t < T0). At this stage, the DC power supply DC charges the energy storage capacitor C i through the inductor L and the diode Da i . The voltage U d across the actuator is consistent with the capacitor voltage and gradually increases from zero to twice the output voltage of the DC power supply.

[0076] Repeating the above process can achieve the continuous operation of the plasma actuator matrix. Since the excitation formation can be set within each working cycle, the surface arc plasma actuator matrix of the present invention can achieve a real-time variable formation. In addition, Figure 3 the shift register set therein greatly reduces the demand for the output ports of the control chip. Only three digital ports are required to complete the adjustment of the formation of a large-scale plasma actuator matrix, greatly saving the hardware deployment cost. In practical engineering applications, when the number of plasma actuators inside the matrix needs to be increased, only the number of power supply units in Figure 2 and the number of output channels of the shift register in Figure 3 need to be correspondingly expanded, and there is no need to redesign the circuit.

[0077] Compared with the traditional scheme, the present invention can conveniently expand the number of discharge circuits. There is no electrical connection between each actuator, and they do not interfere with each other and have strong robustness. The redesigned discharge circuit gets rid of the dependence on the high-voltage trigger power supply. The number of discharge circuits is theoretically unlimited, and pulsed arc discharge plasma excitation of dozens or hundreds of channels can be achieved. In addition, the matrix realizes the real-time variability of the excitation formation by introducing a shift register circuit, greatly improving the adaptability of the arc plasma actuator matrix to complex and variable flight conditions, and is expected to achieve higher flow control efficiency.

Claims

1. A large-scale pulsed arc plasma exciter matrix with real-time variable formation, based on a pulsed surface arc plasma exciter, comprising an insulating substrate, an anode, and a cathode; the anode and cathode are needle-shaped and vertically inserted from the back to the front of the insulating substrate; the tops of the anode and cathode are flush with the upper surface of the insulating substrate; the tops and bottoms of the anode and cathode are exposed; the area below the insulating plate is sealed; the electrode gap between the anode and cathode is determined by the breakdown voltage of the external power supply and the ambient pressure; and the invention is characterized by: Expanding the single arc plasma actuator along the row and column directions to obtain an arc plasma actuator matrix; A real-time variable control circuit is implemented using m shift registers, where the number of registers m satisfies: m≥n / 8, and n is the total number of actuators; each shift register has several bit output ports, and the register also includes the following ports: signal input port DS, power supply port VCC, ground port GND, clear port CLR, and clock signal port CLK; multiple groups of registers are connected end to end.

2. The large-scale pulse arc plasma exciter matrix with real-time variable formation according to claim 1, characterized in that: The electrode gap between the anode and cathode of the pulsed surface arc plasma exciter is 0.5-5 mm; the thickness of the insulating substrate plate is 3 mm-20 mm; The arrangement spacing of the rows and columns of the arc plasma exciter matrix ranges from 5 to 30 mm; The exciters of the matrix are numbered 1, 2, ..., n in order from left to right and from top to bottom.

3. The large-scale pulse arc plasma exciter matrix with real-time variable formation according to claim 2, characterized in that: The electrode gap between the anode and cathode of the pulsed surface arc plasma exciter is 2 mm; The thickness of the insulating substrate sheet is 10 mm; The arrangement spacing of the rows and columns of the arc plasma exciter matrix is ​​in the range of 10 mm; The layout of the arc plasma exciter matrix is ​​a square array, a triangle array or a diamond array.

4. A power supply circuit for a large-scale pulse arc plasma exciter matrix with real-time variable formation, which supplies power to the large-scale pulse arc plasma exciter matrix with real-time variable formation as claimed in any one of claims 1 to 3; characterized in that: Use G1, G2, ..., G n Refers to the exciter 1, 2, ..., n; Each actuator has its own independent power supply unit, and each power supply unit has the same structure. Each actuator is connected to each other through a diode Da i Isolation is performed, i=1,2,…,n, and the discharge is turned on and off by the trigger signal Q i control; The power supply unit of the exciter G2 is specifically as follows: the inductor L, the second isolation diode Da2, the second capacitor discharge diode Db2, and the second exciter G2 are connected in series in sequence between the output terminal of the DC power supply DC and the ground according to the conventional connection method; the second energy storage capacitor C2 is connected between the node between the second isolation diode Da2 and the second capacitor discharge diode Db2 and the ground; the gate of the second switch tube S2 inputs the trigger signal Q2, its drain is connected to the node between the second isolation diode Da2 and the second capacitor discharge diode Db2, and its source is connected to the positive terminal of the primary coil of the second transformer T2; the negative terminal of the second trigger discharge diode Dc2 is connected to the node between the second capacitor discharge diode Db2 and the second exciter G2, and its positive terminal is connected to the positive terminal of the secondary coil of the second transformer T2; the negative terminal of the primary coil and the negative terminal of the secondary coil of the second transformer T2 are grounded.

5. The power supply circuit of the large-scale pulse arc plasma exciter matrix with real-time variable formation according to claim 4, characterized in that: The second switch tube S2 is a transistor, a metal oxide semiconductor field effect tube MOSFET or other power electronic switches.

6. The power supply circuit of the large-scale pulse arc plasma exciter matrix with real-time variable formation according to claim 4, characterized in that: The specific working principle of the power supply circuit is as follows: (1) The DC power supply DC, the inductor L, the first isolation diode Da1 and the first energy storage capacitor C1 form a voltage doubling charging circuit; after the voltage doubling charging is completed, the voltage across the first energy storage capacitor C1 is twice the output voltage U0 of the DC power supply DC; to ensure that the gas gap does not automatically break down during the charging process, the output voltage U0 of the DC power supply DC should be less than the breakdown voltage U across the first exciter G1. b Half of the maximum output power of the DC power supply P max The output voltage U0 of the DC power supply, the total number of actuators n, and the maximum operating frequency F of the actuator are max And the first energy storage capacitor C1 is determined by the following formula: P max =2nF max C1U0 2 (1) During the charging process, the inductor L plays the role of limiting the charging current and storing electrical energy; since the maximum output current I max =P max / U0, so the minimum inductance value of the inductor is L min By solving the second-order differential equation of the voltage-doubling charging circuit, we can obtain: When the inductance value is too small, that is, L <L min When the inductance is too high, the charging current of the circuit will exceed the maximum output current of the DC power supply, causing the DC power supply DC output to be overloaded; on the contrary, when the inductance value is too large, it will cause the charging time to be too long, affecting the maximum discharge operating frequency of the exciter; the withstand voltage of the first diode Da1 should be higher than twice the DC power supply DC output voltage, and the rated current should be greater than the maximum output current I of the DC power supply DC. max The withstand voltage of the first energy storage capacitor C1 should be greater than twice the DC power supply DC output voltage; (2) The first energy storage capacitor C1, the first switch tube S1 and the first transformer T1 form a pulse boost circuit; when the first trigger signal Q1 is at a high level, the first switch tube S1 is quickly turned on, and the voltage across the first energy storage capacitor C1 is quickly loaded on the primary coil of the first pulse transformer T1; due to electromagnetic induction, a high-voltage pulse will be generated on the secondary coil of the first pulse transformer T1, and its amplitude is determined by the turns ratio k of the first pulse transformer T1; the switching time of the first switch tube S1 can reach the order of 0, and the withstand voltage value is more than twice the energy storage capacitor voltage; (3) The first transformer T1, the first diode Dc1, and the first exciter G1 form a trigger discharge circuit; the high-voltage pulse generated by the secondary coil of the first pulse transformer T1 passes through the first diode Dc1 and is applied to the first exciter G1; when the voltage exceeds the breakdown voltage of the gas gap, a discharge plasma channel is generated between the two electrodes of the first exciter G1; since the output current of the secondary coil is very small, the arc discharge at this time is relatively weak, belonging to a high-voltage, low-current triggered discharge; after the triggered discharge is formed, the first switch tube S1 is closed; (4) The first energy storage capacitor C1, the first diode Db1 and the first exciter G1 form a capacitor discharge circuit; before the high-voltage triggered discharge, since the voltage across the first energy storage capacitor C1 is less than the gas gap breakdown voltage of the first exciter G1, no current flows through the circuit; during the high-voltage triggered discharge, the gas gap is broken down, forming a conductive plasma channel between the anode and the cathode; therefore, a large amount of electrical energy stored in the first energy storage capacitor C1 is rapidly injected into the gas gap between the anode and the cathode through the first diode Db1, forming a strong arc discharge; when the electrical energy in the energy storage capacitor is completely released, the discharge channel is extinguished, and a working cycle ends.

7. The power supply circuit of the large-scale pulse arc plasma exciter matrix with real-time variable formation according to claim 6, characterized in that: Choose a DC power supply below 1kV; The capacitance value of the second energy storage capacitor C2 ranges from 0.1uF to 10uF; In order to be able to break through the gas gap of 2-5 mm, the amplitude range of the high voltage pulse is 10-30 kV; the turn ratio value of the first pulse transformer T1 is 5-20.

8. The power supply circuit of the large-scale pulse arc plasma exciter matrix with real-time variable formation according to claim 7, characterized in that: The capacitance of the second energy storage capacitor C2 is 1uF; In order to penetrate the gas gap of 2-5 mm, the amplitude of the high-voltage pulse is 20 kV; the turn ratio of the first pulse transformer T1 is 10.

9. A method for implementing real-time variable control of an actuator matrix array using a shift register, based on the large-scale pulsed arc plasma actuator matrix with real-time variable array according to any one of claims 1 to 3, characterized in that: The control chip can provide three high-speed digital signal output ports DO1, DO2, and DO3; A real-time variable control circuit is implemented using m shift registers, where the number of registers m satisfies m≥n / 8; each shift register has a number of bit output ports; The register also includes the following ports: signal input port DS (1), power supply port VCC (10), ground port GND (11), clear port CLR (12), clock signal port CLK (13); Multiple groups of registers are connected end to end to ensure that the sum of the output bits of all registers is greater than the total number of trigger signal channels required by the exciter matrix; Power the shift register and control chip; the negative pole of the power supply is connected to the GND port of each shift register module; the positive pole of the power supply is directly connected to the VCC port of each shift register module, and then connected to the CLR port of each shift register module through a NOT gate; the DO1 port of the control chip outputs the clock signal, which is connected to the clock port CLK of each shift register; the DO3 port of the control chip is the output enable signal ENB, which is used as the actual trigger signal Q of the exciter discharge circuit after the logic AND operation with the output signal of each shift register. i Output, i = 1, 2, ..., n; DO2 port is connected to the signal input port DS of shift register 1, the highest bit output signal Q8 of shift register 1 is connected to the signal input port DS of shift register 2, and so on. By connecting the highest bit output signal of the previous shift register to the signal input port DS of the next shift register, all shift registers are connected in series.

10. A method for implementing real-time variable control of an actuator matrix array using a shift register, characterized in that: A complete working cycle of the variable array plasma actuator matrix includes four stages: the excitation array setting stage, the high-voltage trigger discharge stage, the capacitor discharge stage, and the capacitor charging stage; the details are as follows: (1) Incentive formation setting stage, 0≤t <t A ; The control chip sets the ENB enable signal of the DO1 channel to a low level to ensure that there will be no discharge trigger instruction Q i Output from the AND gate; DO3 channel sends a series of clock signals CLK, and DO2 channel outputs the discharge information of each actuator in the arc plasma actuator matrix in the form of high and low levels in reverse order to the DS port of shift register 1; since the shift register shifts at the rising edge of the clock signal, the total number of rising edges of the clock signal should be equal to the sum of the number of bits of all shift registers; when the clock signal CLK ends, the shift register completes the conversion from serial array input to parallel array output, and the high and low levels of each output port represent the working information of the corresponding actuator; (2) High voltage trigger stage, t A ≤t <t B ; The DO1 channel of the control chip sets the enable signal ENB to a high level; the exciter matrix trigger signal stored in the shift register passes through the AND gate and is loaded into the switch tube S at the same time. i Each trigger channel Q i On, i=1,2,…,n; when Q i =1, the corresponding switch tube S i Open, exciter G i The voltage across the two ends is U d Rapidly rise from the capacitor voltage to the breakdown voltage, forming a high-voltage trigger discharge channel in the gas gap; On the contrary, if Q i = 0, the exciter G i When the discharge trigger is completed, the control chip sets the ENB enable signal to a low level, and the switch tube S i In the closed state, preparing for the next step of capacitor charging; (3) Capacitor discharge stage, t B ≤t <t C ; For the exciter G that has triggered discharge i , energy storage capacitor C i The stored electrical energy is rapidly injected into the gas gap to form a pulsed arc plasma discharge of a specified formation; in this process, the discharge current I d First it increases and then decreases; when the capacitor energy is exhausted, the arc goes out and the discharge current becomes 0; (4) Capacitor charging stage, t C ≤t <T0; The DC power supply DC passes through the inductor L and the diode Da i , for the energy storage capacitor C i Charging; the voltage U across the exciter d Keeping consistent with the capacitor voltage, both start from zero and gradually increase to twice the DC power supply output voltage.

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