CN115515289A - Nanosecond pulse dielectric barrier discharge supercharging array plasma synthetic jet device - Google Patents

Abstract

A nanosecond pulse dielectric barrier discharge supercharged array plasma synthesis jet actuator comprises the following components from top to bottom: top cover 10, high voltage electrode plate 20, insulating dielectric plate 30 and grounding metal plate 40. The working method of the nanosecond pulse dielectric barrier discharge pressurized array plasma synthetic jet device based on the exciter is further provided, and in a jet cycle, the complete working process comprises three stages: an impingement pressurization phase, an array jet phase and a porous suction recovery phase. The array exciter does not need complex load matching circuit design or power supply optimization design, and has the advantages of simple wiring, low implementation cost, easy large-scale expansion, high working frequency, good pulse repeatability and the like.

Description

Array Plasma Synthetic Jet Device Boosted by Nanosecond Pulse Dielectric Barrier Discharge

technical field

The invention relates to the field of active flow control, in particular to an array plasma synthetic jet exciter which adopts nanosecond pulse dielectric barrier discharge impact pressurization.

Background technique

Active flow control technology was listed by the American Institute of Aeronautics and Astronautics in 2010 as one of the ten key technologies supporting the future development of the global aviation field. The core of this technology is the exciter, which induces controllable disturbances to achieve the purpose of changing the external flow field of the aircraft and improving the performance of the aircraft and the engine. The plasma synthetic jet actuator is a high-intensity actuator with zero mass flow rate. Its basic working principle is to quickly heat and pressurize the gas gap inside the semi-closed cavity through pulsed arc, and induce the jet to periodically flow from Small holes spray out. The maximum jet velocity of the exciter can reach 500m/s, and the maximum operating frequency exceeds 10kHz. Therefore, it is especially suitable for flow control at high speed and high Reynolds number. However, due to the limited gas area that can be heated by a single arc, the cavity size of plasma synthetic jet actuators is generally between 5-15mm. The corresponding jet aperture is generally set at 1-3mm, and the range of the flow field that can be controlled is extremely limited. In order to apply active flow control technology to large civil aviation airliners and fighter jets, dozens or even hundreds of plasma synthetic jet actuators must be expanded into an array to achieve a flow field control capability of the order of 0 (1-10m). Due to the negative impedance characteristic of arc discharge, parallel connection of multiple plasma synthetic jet exciters directly cannot realize the simultaneous work of the exciters inside the array. At present, there are two types of schemes for realizing array plasma synthetic jets. One is to optimize the power supply design, divide the high-voltage output end of the plasma synthetic jet power supply into several relatively independent circuits; each circuit has an energy storage device, which can output a pulse of high voltage to supply power to the exciter, and finally realize The "synchronous work" of each exciter inside the array; a typical representative of this type of scheme is "CN105119517A, Shao Tao, Wang Lei, Zhang Zhang, Yan Ping, Luo Zhenbing, Wang Lin; High-voltage pulses of synchronous discharge of multiple plasma synthetic jet exciters Power supply", "CN104682765A, Shao Tao, Wang Lei, Zhang Zhang, Yan Ping, Luo Zhenbing, Wang Lin; device and method for synchronous discharge of multiple plasma synthetic jet actuators". The second is to carry out load matching design, connect resistors, capacitors and other components in series and parallel with the gas discharge gap, so as to ensure that the voltage in the discharge circuit will not drop significantly before and after the breakdown; finally, high-voltage pulses can be transmitted in sequence to realize each plasma in the array. "Sequential breakdown" of solid synthetic jet actuators; a typical representative of this type of scheme is "CN110933832A, Wu Yun, Zhang Zhibo, Jin Di, Gan Tian, Song Huimin, Jia Min, Liang Hua; single power supply drive array plasma synthetic jet Flow control device and flow control method", "CN106050593, Shao Tao, Han Lei, Luo Zhenbing, Sun Yaohong, Wang Lin, Yan Ping; Plasma synthetic jet series discharge device based on Marx generator".

However, the above two types of solutions all have many problems in aviation applications. In the first type of scheme, every time an exciter is added, an additional high-voltage energy storage capacitor and several high-voltage silicon stacks are required. When used for powering large-scale plasma exciter arrays, the power supply is bulky, expensive, and unacceptable in weight. The load matching components in the second type of scheme are all low-power devices, which are relatively cheap, but the overall wiring is complicated; the operating frequency of the circuit is determined by the charging rate of the front-end large-capacity energy storage capacitor and the breakdown of the first electrode gap Depending on the voltage, the pulse frequency cannot be adjusted in real time, and the typical operating frequency is only 10Hz; and affected by the fluctuation of the breakdown voltage of the electrode gap, the repeatability of the pulse is poor (Zhibo Zhang, Yun Wu, Min Jia et al. The multichannel discharge plasma synthetic jet actuator, Sensors and Actuators A: Physical, 2017, 253: 112-117). Therefore, how to generate a high-frequency, high-repeatability plasma synthetic jet array at low cost is a technical problem that needs to be solved urgently.

Contents of the invention

Aiming at the problems existing in the prior art, the present invention proposes a nanosecond pulse dielectric barrier discharge supercharged array plasma synthetic jet actuator, including: a top cover 10, a high voltage electrode plate 20, an insulating dielectric plate 30 and a grounded metal plate 40 ;in

The top cover 10 is a rectangular body made of insulating material, with a square upper surface; the length and width of the outer contour of the top cover 10 need to be adaptively designed according to the actual application; the inside of the top cover 10 is hollowed out; a rectangular internal cavity is formed, and the lower part Open, when combined with the high-voltage electrode plate 20 and the insulating medium plate 30, a semi-closed, flat square plasma discharge cavity, that is, the exciter cavity 105 is formed; on the upper surface of the top cover 10, along Perpendicular to the direction of the wall surface, a number of convergent jet holes 102 are processed from bottom to top, and the jet holes 102 are small at the top and large at the bottom; these jet holes 102 are arranged in an N×M array, as gas flows in from top to bottom and outflows from bottom to top The throat of the exciter cavity 105; the throat outlet 101 on the upper surface of the top cover 10 is circular; the throat inlet 103 on the upper surface of the exciter cavity 105 is also circular; the central axis of the jet hole is perpendicular to the top cover 10 upper surface, or form a certain angle with the normal line of the top cover 10; as long as it is ensured that the area of the lower entrance of the jet hole 102 is greater than the area of the upper exit, and the cross-sectional area from bottom to top, from the entrance to the exit is monotonously reduced;

The electrode plate 20 is made of thin sheet metal; the electrode plate has a dense mesh shape; the position of each jet hole array 102 corresponds to a mesh, and the axes of the two coincide; the center distance between adjacent jet holes is the same as that of the adjacent mesh The distance between the centers is the same; the outermost ring mesh and the edge of the electrode plate 20 maintain a certain distance; the length and width of the electrode plate 20 are basically the same as the length and width of the exciter cavity 105, which is convenient for the electrode plate 20 to be placed from bottom to top. embedded in the top cover 10;

The insulating dielectric plate 30 is a sheet-shaped rectangular body; the projection of the insulating dielectric plate 30 on the horizontal plane coincides with the projection of the top cover 10, that is, the length and width of the two are the same;

The grounding metal plate 40 is a sheet-shaped rectangular body; the projection of the grounding metal plate 40 on the horizontal plane coincides with the projection of the top cover 10, that is, the length and width of the insulating dielectric plate 30 and the grounding metal plate 40 are the same as those of the housing 10; during installation, The lower surface of the insulating medium plate 30 is tightly combined with the upper surface of the grounding metal plate 40; the shell 10, the electrode plate 20, the insulating medium plate 30 and the grounding metal plate 40 are assembled together from top to bottom in order to form an exciter.

In one embodiment of the invention,

The thickness of the top cover 10 is 4-6mm; the length and width of the outer contour of the top cover 10 are 50mm-500mm;

The throat outlet 101 has a diameter in the range of 1-2 mm; the throat inlet 103 has a diameter in the range of 2-4 mm;

The throat length of the converging jet holes 102 is 1-3mm; the row spacing and column spacing of the jet hole array 102 should be set to 3-5 times the diameter of the throat outlet, and the range is 3-15mm.

In a specific embodiment of the present invention,

The top cover 10 has a thickness of 4mm and is made of insulating materials such as nylon, polyimide, PEEK or ceramics; the outer contour length and width of the top cover 10 are 50mm*50mm;

The shape of the jet hole 102 is a frustum, and the upper surface of the frustum is parallel to the lower surface;

The throat outlet 101 has a diameter of 1.5 mm; the throat inlet 103 has a diameter of 3 mm;

The throat length of the converging jet hole 102 is 2mm.

In another embodiment of the present invention,

The thickness of the electrode plate 20 is 0.01mm-1mm (preferably 0.05mm);

The maximum diameter of the mesh of the electrode plate 20 is 2-5 mm (preferably 4 mm).

In another specific embodiment of the present invention,

The thickness of the electrode plate 20 is 0.05mm;

The maximum diameter of the mesh of the electrode plate 20 is 4mm;

The electrode plate 20 is a dense square grid, a triangular grid, a honeycomb network, or a comb-like network.

In yet another embodiment of the present invention, the insulating dielectric plate 30 is made of insulating materials such as polyimide, nylon, acrylic, PPEK, ceramics or mica; when using thin film polyimide, the thickness range is 0.05-0.2 mm; when using other materials, the thickness range is 0.5-2mm.

In yet another embodiment of the present invention, the thickness of the ground metal plate 40 is in the range of 2-4 mm.

In yet another embodiment of the present invention, the depth of the exciter cavity 105 is 1-4 mm; the thickness of the side wall of the top cover 10 is 4-10 mm.

It also provides a working method of a nanosecond pulse dielectric barrier discharge supercharged array plasma synthetic jet device, the device is based on the nanosecond pulse dielectric barrier discharge supercharged array plasma synthetic jet actuator, wherein the high-voltage nanosecond pulse The high-voltage output end of the power supply 50 is connected to the electrode plate 20 through the lead wire 201, and the grounding end is connected to the ground metal plate 40 through the lead wire 401; it is characterized in that, in a jet cycle, the complete working process includes three stages: impact boosting stage, array jet stage and porous suction recovery stage;

step1, in the stage of impact boosting, the high-voltage nanosecond pulse power supply 50 outputs a high-voltage pulse and applies it on the electrode plate 20; because there is a tip effect and the electric field intensity is concentrated at each edge of the electrode plate 20, the first near the edge A discharge current column is generated; under the action of the rising edge of the high-voltage nanosecond pulse, the current column continues to expand outward along the direction of the electric field, forming a dielectric barrier discharge plasma area near the edge of the electrode; in this area, some gas molecules are ionized The incoming high-energy electrons continuously bombard other unionized gas molecules, producing a large number of excited state particles; these excited state particles release a large amount of heat during the extinguishing process, heating the temperature of the gas in the plasma region on a nanosecond time scale High-temperature gas is formed; due to the extremely short heating time scale, the high-temperature gas has no time to expand, so the pressure in the plasma region increases sharply, inducing the shock wave 106; the shock wave 106 propagates from the plasma region toward the surroundings, through continuous reflection and convergence, Raise the temperature and pressure of the entire exciter cavity 105 to a level much higher than atmospheric pressure; so far, the impact boosting stage is completed;

Step 2. In the stage of jet array, driven by the high pressure inside the exciter cavity 105, high-temperature gas is ejected from the convergent jet hole 102 from the inside out to form a high-speed jet array 60, which is used for supersonic or other occasions Flow control; during the injection process of the jet, the pressure inside the actuator cavity 105 will continue to decrease; when the pressure inside the cavity 105 is less than or equal to the atmospheric pressure, the jet ends, the actuator starts to cool, and enters the porous suction recovery;

Step 3. In the recovery stage of porous air suction, the interior of the actuator cavity 105 begins to cool down, and the corresponding gas pressure gradually decreases; affected by the negative pressure difference inside and outside the jet throat, the air suction flow 70 is formed; specifically, the outside of the actuator The normal-temperature, high-density gas is sucked into the interior of the exciter cavity 105 from the convergent jet hole array 102, and mixed with the expanded high-temperature, low-density gas to restore the exciter to its original working state; after complete restoration, the high-pressure The nanosecond pulse power supply 50 can output the next high-voltage pulse to realize the repetition frequency work of the exciter.

Based on the rapid heating effect of nanosecond pulse dielectric barrier discharge, the invention proposes a novel array type plasma synthetic jet exciter. Compared with traditional solutions, the array exciter does not require complex load matching circuit design or power supply optimization design, and has the advantages of simple wiring, low implementation cost, easy large-scale expansion, high operating frequency, and good pulse repeatability.

Description of drawings

Fig. 1 shows the structure of the array plasma synthetic jet exciter, wherein Fig. 1(a) shows an assembly view, and Fig. 1(b) shows an exploded view;

Fig. 2 shows the structure of exciter top cover 10, wherein Fig. 2 (a) shows top view; Fig. 2 (b) shows bottom view; Fig. 2 (c) shows B-B cross-sectional view; Fig. 2 (d) shows A perspective view when the bottom of the top cover 10 is placed upwards;

Figure 3 shows the three working stages of the exciter (A-A cross-sectional view), in which Figure 3(a) shows the shock boost stage; Figure 3(b) shows the array jet stage; Figure 3(c) shows the porous suction stage gas recovery phase.

Notes on drawings:

0 Top cover 101 Throat outlet 102 Convergent jet hole 103 Throat inlet 104 Threaded hole

105 exciter cavity 106 shock wave 20 high voltage electrode plate 201 high voltage lead

30 insulating dielectric plate 301 positioning through hole 40 grounding metal plate 401 grounding lead

402 through holes 50 high-voltage nanosecond pulse power supply 60 high-speed jet 70 suction flow

detailed description

Figure 1-2 shows the basic structure of the array plasma synthetic jet actuator boosted by nanosecond pulse dielectric barrier discharge. The exciter mainly includes four parts: a top cover 10 , a high voltage electrode plate 20 , an insulating medium plate 30 and a grounding metal plate 40 .

The top cover 10 is a rectangular body with a square upper surface and a thickness of 4-6 mm (preferably 4 mm), made of insulating materials such as nylon, polyimide, PEEK or ceramics. The length and width of the outer contour of the top cover 10 need to be adaptively designed according to the actual application, and the typical range is 50mm-500mm. In a preferred embodiment of the present invention, the length and width are 50mm*50mm. The inside of the top cover 10 is hollowed out. A rectangular inner cavity is formed, and the lower part is open. When matched together with the high-voltage electrode plate 20 and the insulating medium plate 30, a semi-closed, flat square plasma discharge cavity, that is, the exciter cavity 105, is specifically as Details will be given later. On the upper surface of the top cover 10, along the direction perpendicular to the wall, several convergent jet holes 102 are processed from bottom to top. The jet holes 102 are small at the top and large at the bottom. The shape of the hole 102 is a frustum, the upper surface of which is parallel to the lower surface. These jet holes 102 are arranged in an N×M array, serving as throats for gas to flow in from top to bottom and out of the actuator cavity 105 from bottom to top. The throat outlet 101 located on the upper surface of the top cover 10 is circular, with a typical diameter in the range of 1-2mm (preferably 1.5mm). The throat inlet 103 (at the lower end of the jet hole 102 ) located on the upper surface of the exciter cavity 105 is also circular, with a typical diameter ranging from 2-4mm (preferably 3mm). Since the gas flow is conserved when the gas flows inside the pipeline, the design of the convergent jet hole 102 can make the gas accelerate when the gas flows out of the actuator cavity 105 from bottom to top, which helps to increase the exit velocity of the plasma synthetic jet . The throat length of the converging jet hole 102 (that is, the thickness of the upper wall surface of the top cover 10 ) will directly affect the saturation operating frequency of the exciter. If the throat is too long, the inspiratory time of the exciter will be longer and the saturation working frequency will be reduced; if the throat is too short, the structural strength will be insufficient. Considering comprehensively, the throat length of the converging jet hole 102 is typically in the range of 1-3 mm (preferably 2 mm). The row spacing and column spacing of the jet hole array 102 should be set to 3-5 times the diameter of the throat outlet, and the range is 3-15mm (5mm in the embodiment shown in Fig. 1-2). It should be noted that the outlet of the converging jet hole 102 can also adopt configurations such as long slit holes and polygonal holes in addition to being circular; the central axis of the jet hole can also be in a certain shape except that it is perpendicular to the upper surface of the top cover 10. The angle (that is, the bevel configuration). As long as it is ensured that the lower inlet area of the jet hole 102 is larger than the upper outlet area, and the cross-sectional area decreases monotonously from bottom to top, from the inlet to the outlet.

The electrode plate 20 is made of a thin metal plate, which is made of copper, silver, aluminum and other metal materials with good electrical conductivity, with a typical thickness of 0.01mm-1mm (preferably 0.05mm). In the embodiment shown in Figs. 1-2, the electrode plate has a dense circular mesh shape, and the diameter of each circular mesh typically ranges from 2-5mm (preferably 4mm). The position of each jet hole array 102 corresponds to a circular mesh, and the two axes coincide; the center-to-center spacing of adjacent jet holes is the same as the center-to-center spacing of adjacent circular meshes, and in the illustrated embodiment, the center-to-center spacing 5mm; the outermost circular mesh and the edge of the electrode plate 20 are kept at a certain distance. The mesh shape, diameter, spacing and arrangement are not unique, and those skilled in the art can make appropriate adjustments according to the expected dielectric barrier discharge heating power per unit area. In addition, the electrode plate 20 can also be designed in other configurations such as a dense grid, a triangular grid, a honeycomb grid, or a comb-like grid. If it is a square grid, a triangular grid or a honeycomb network, the central axis of a single mesh can be aligned with the jet hole or not, as long as it has the two characteristics of dense and mesh, and the purpose is to increase the density per unit area. Plasma heating power and heating uniformity all belong to the category of the present invention. In terms of technology, the electrode plate 20 can be made of a thin metal plate as the base material, and the corresponding grid-like configuration can be obtained by chemical etching or laser cutting; it can also be formed by screen printing, mask etching, magnetron sputtering and other processes. The electrode plate 20 is directly deposited on the insulating dielectric plate 30 to form an electrode coating. Laser cutting methods or screen printing processes with low processing costs are preferred. The length and width of the electrode plate 20 are basically the same as those of the exciter cavity 105 , which facilitates the electrode plate 20 to be embedded in the top cover 10 from bottom to top.

The insulating dielectric plate 30 is a sheet-like rectangular body made of insulating materials, such as polyimide, nylon, acrylic, PPEK, ceramics or mica, and other insulating materials. The insulating dielectric plate 30 is used for high-voltage insulation to prevent the electrode plates from An arc discharge is formed between 20 and the grounded metal plate 40 . The projection of the insulating medium plate 30 on the horizontal plane coincides with the projection of the top cover 10 , that is, the length and width of the two are the same. When using thin film polyimide, the typical thickness range is 0.05-0.2 mm (preferably 0.2 mm); when other materials are used, the typical thickness range is 0.5-2 mm (preferably 1 mm).

The grounding metal plate 40 is a thin rectangular body made of metal materials such as copper, aluminum or stainless steel, preferably stainless steel from the perspective of structural strength and raw material price, and its function is to serve as the grounding electrode of the nanosecond pulse dielectric barrier discharge. The typical thickness range of the ground metal plate 40 is 2-4mm, preferably 3mm. The projection of the grounding metal plate 40 on the horizontal plane coincides with the projection of the top cover 10, that is, the length and width of the insulating dielectric plate 30 and the grounding metal plate 40 are the same as those of the housing 10, and those skilled in the art need to adjust the parameters according to the application. select. During installation, the lower surface of the insulating dielectric plate 30 is closely bonded to the upper surface of the grounded metal plate 40 (for example, double-sided adhesive tape or other quick-drying glue is used for bonding).

The shell 10, the electrode plate 20, the insulating medium plate 30 and the ground metal plate 40 are assembled together to constitute the exciter in the present invention. The assembly of each component can be completed by glue bonding or threaded butt joint. In the specific embodiment shown in Figs. 1-2, a threaded butt joint is used. First, on the four corners of the casing 10, along the vertical direction, four standard threaded holes 104 are opened from bottom to top; four positioning through holes 301 are opened on the corresponding positions of the insulating medium plate 30; Four passing holes 402 are opened at corresponding positions of the top corners of the metal plate. Then, the lower surface of the electrode plate 20 is pasted on the upper surface of the insulating medium plate 30 by glue. Finally, four screws are used to sequentially pass through the through hole 402, the positioning through hole 301 and the threaded hole 104 from bottom to top to realize the assembly and cooperation of the various parts of the actuator.

The depth of the exciter cavity 105 is determined by the gas range that can be heated by the nanosecond pulse dielectric barrier discharge in the vertical direction, and the typical value is 1-4 mm (preferably 2 mm). The depth of the exciter cavity 105 only refers to the height of the hollowed-out area inside, excluding the height of the jet hole 102 and the thickness of the electrode plate 20 . The length and width of the actuator cavity 105 can be obtained from the length and width of the top cover 10 minus the thickness of the side wall of the top cover. In order to ensure structural strength and facilitate screw fixing, the thickness of the side wall of the top cover 10 is typically in the range of 4-10 mm, which is set to 4 mm in Fig. 1-2. The resulting length and width of the exciter cavity 105 in FIGS. 1-2 are 42mm*42mm, respectively.

The electrode plate 20, the insulating dielectric plate 30 and the grounded metal plate 40 together form a sandwich type dielectric barrier discharge structure.

The electrode plate 20 is connected to an external nanosecond pulse high-voltage power supply through a high-voltage lead 201 , and the grounded metal plate 40 is connected to the common ground of the nanosecond pulse high-voltage power supply through a ground lead 401 . After the power is turned on, the air is rapidly heated and pressurized by generating a dielectric barrier discharge plasma at all edges of the densely meshed electrode plate 20 (including the rectangular outer edge and the circular inner edge of each mesh). The traditional plasma synthetic jet exciter is heated by arc discharge, the energy is concentrated in the air gap of about 5mm, and the energy of a single pulse can reach more than 100mJ. The single-pulse heating energy of nanosecond pulse discharge plasma is generally 10-50mJ, and the average energy on the same air gap is much smaller. Therefore, in order to meet the heating energy demand per unit area, the electrode plate 10 must have a dense mesh feature in appearance, so as to greatly increase the total length and discharge power of the discharge plasma per unit area; the final effect is: mesh Each edge of the electrode plate (including both the rectangular outer edge and the circular inner edge of each mesh) is a tiny rapid discharge heating source, and multiple rapid discharge heating sources closely arranged are combined to achieve the same The traditional "heating wire" heating film has a similar function, so as to achieve the purpose of quickly and uniformly heating the air inside the exciter cavity 105 .

Next, with reference to FIG. 3 , the working method of the array plasma synthetic jet actuator for impingement pressurization by nanosecond pulse dielectric barrier discharge will be described. The power supply circuit of the array exciter is extremely simple, and only needs a high-voltage nanosecond pulse power supply 50 (output voltage: 10-20kV, maximum repetition rate: 10kHz). The high-voltage output end of the high-voltage nanosecond pulse power supply 50 is connected to the electrode plate 20 through a lead wire 201 (not shown), and the ground end is connected to the ground metal plate 40 through a lead wire 401 . In a jet cycle, the complete working process includes three stages: impact pressurization stage, array jet stage and porous suction recovery stage.

1. In the shock boost stage, the high-voltage nanosecond pulse power supply 50 outputs a high-voltage pulse and applies it to the electrode plate 20 . Since there is a tip effect and electric field intensity concentration at each edge of the electrode plate 20, the discharge current column is first generated near the edge. Under the action of the rising edge of the high-voltage nanosecond pulse, the current column continuously expands outward along the direction of the electric field, forming a dielectric barrier discharge plasma region near the edge of the electrode. In this region, high-energy electrons ionized by some gas molecules continuously bombard other unionized gas molecules, producing a large number of excited state particles. During the extinction process of these excited particles, a large amount of heat is released, and the temperature of the gas in the plasma region is heated to more than 1000K in the nanosecond time scale, forming a high-temperature gas. Since the heating time scale is extremely short, the high-temperature gas has no time to expand, so the pressure in the plasma region increases sharply, and shock waves 106 are induced. The shock wave 106 propagates from the plasma region toward the surroundings, and through continuous reflection and convergence, the temperature and pressure of the entire exciter chamber 105 are raised to a level much higher than atmospheric pressure. So far, the shock boost stage is completed.

2. In the jet array stage, driven by the high pressure inside the exciter cavity 105, high-temperature gas is ejected rapidly from the convergent jet holes 102 from the inside to the outside to form a high-speed jet array 60, which is used for supersonic or other occasions. control. During the ejection process of the jet, the pressure inside the actuator cavity 105 will continuously decrease. When the pressure inside the cavity 105 is less than or equal to the atmospheric pressure, the jet flow ends, the actuator starts to cool down, and enters the multi-hole suction recovery.

3. In the recovery stage of porous suction, the inside of the actuator cavity 105 starts to cool down, and the corresponding gas pressure gradually decreases. Inspiratory flow 70 is formed by the negative pressure difference inside and outside the jet throat. Specifically, the normal-temperature, high-density gas outside the exciter is sucked from the convergent jet hole array 102 into the interior of the exciter cavity 105, and mixed with the expanded high-temperature, low-density gas to restore the exciter to its original working state. state. After complete recovery, the high-voltage nanosecond pulse power supply 50 can output the next high-voltage pulse to realize the repetition frequency operation of the exciter.

From the above working principle and structural description, it is not difficult to conclude that the main innovation in the technical solution of the present invention is to replace the traditional pulsed arc discharge with dense network nanosecond pulse dielectric barrier discharge, which can realize the large-area plasma synthetic jet actuator The fast space of the chamber heats up evenly. The advantages and effects of this program are reflected in the following aspects:

1. Low cost and simple power supply. This solution uses a mature nanosecond pulse power supply on the market, and does not require any power supply modification and load matching circuit design. The power supply research and development cost is greatly saved, and the problem that the traditional solution requires a large-volume power supply and complicated wiring to supply power to the array plasma synthetic jet can be overcome.

2. Easy to expand. Since the nanosecond pulse dielectric barrier discharge plasma is a capacitive load, there is no disadvantage of the "negative impedance load characteristic" of arc discharge. Therefore, no matter how large the area of the plasma synthetic jet array is, a nanosecond pulse power supply can be used for power supply. It is easy to expand the area of the actuator jet array according to specific needs in actual flow control applications.

3. High synchronization precision. Compared with the array plasma synthetic jet based on the "sequential breakdown" principle, the plasma on the entire surface of the electrode plate in this scheme is generated simultaneously without any delay, and the injection of each jet hole inside the array is strictly synchronized.

4. High frequency and good repeatability. Compared with the array plasma synthetic jet based on the principle of "sequential breakdown", the injection frequency of the jet in the present invention is completely determined by the discharge frequency of the high-voltage nanosecond pulse power supply 50 and the resonance frequency of the exciter cavity, and there is no front end There will be no frequency instability caused by breakdown voltage fluctuations in the charging circuit, and the typical frequency can reach more than 10kHz.

Claims (9)

1. The nanosecond pulse dielectric barrier discharge supercharged array plasma synthetic jet exciter is characterized in that it includes: a top cover 10, a high voltage electrode plate 20, an insulating dielectric plate 30 and a grounded metal plate 40; wherein the top cover 10 is an insulating Rectangular body made of material, the upper surface is square; the outer contour length and width of the top cover 10 need to be adaptively designed according to the actual application; the top cover 10 is hollowed out; a rectangular internal cavity is formed, and the lower part is open. After the electrode plate 20 and the insulating medium plate 30 are matched together, a semi-closed, flat square plasma discharge cavity, that is, the exciter cavity 105 is formed; on the upper surface of the top cover 10, along the direction perpendicular to the wall, Several convergent jet holes 102 are processed from bottom to top, and the jet holes 102 are small at the top and large at the bottom; these jet holes 102 are arranged in an N×M array, as the gas flows in from top to bottom and out of the exciter cavity 105 from bottom to top throat; the throat outlet 101 on the upper surface of the top cover 10 is circular; the throat inlet 103 on the upper surface of the exciter cavity 105 is also circular; the central axis of the jet hole is perpendicular to the upper surface of the top cover 10, or It is at a certain angle with the normal line of the top cover 10; as long as the entrance area of the lower part of the jet hole 102 is greater than the area of the upper exit, and the cross-sectional area from bottom to top, from the entrance to the exit is monotonously reduced; The electrode plate 20 is made of thin sheet metal; the electrode plate has a dense mesh shape; the position of each jet hole array 102 corresponds to a mesh, and the axes of the two coincide; the center distance between adjacent jet holes is the same as that of the adjacent mesh The distance between the centers is the same; the outermost ring mesh and the edge of the electrode plate 20 maintain a certain distance; the length and width of the electrode plate 20 are basically the same as the length and width of the exciter cavity 105, which is convenient for the electrode plate 20 to be placed from bottom to top. embedded in the top cover 10; The insulating dielectric plate 30 is a sheet-shaped rectangular body; the projection of the insulating dielectric plate 30 on the horizontal plane coincides with the projection of the top cover 10, that is, the length and width of the two are the same; The grounding metal plate 40 is a sheet-shaped rectangular body; the projection of the grounding metal plate 40 on the horizontal plane coincides with the projection of the top cover 10, that is, the length and width of the insulating dielectric plate 30 and the grounding metal plate 40 are the same as those of the housing 10; during installation, The lower surface of the insulating medium plate 30 is tightly combined with the upper surface of the grounding metal plate 40; the shell 10, the electrode plate 20, the insulating medium plate 30 and the grounding metal plate 40 are assembled together from top to bottom in order to form an exciter. 2. The array plasma synthetic jet exciter of nanosecond pulse dielectric barrier discharge supercharging as claimed in claim 1, is characterized in that, The thickness of the top cover 10 is 4-6mm; the length and width of the outer contour of the top cover 10 are 50mm-500mm; The throat outlet 101 has a diameter in the range of 1-2 mm; the throat inlet 103 has a diameter in the range of 2-4 mm; The throat length of the converging jet holes 102 is 1-3mm; the row spacing and column spacing of the jet hole array 102 should be set to 3-5 times the diameter of the throat outlet, and the range is 3-15mm. 3. The array plasma synthetic jet exciter of nanosecond pulse dielectric barrier discharge supercharging as claimed in claim 1, is characterized in that, The top cover 10 has a thickness of 4mm and is made of insulating materials such as nylon, polyimide, PEEK or ceramics; the outer contour length and width of the top cover 10 are 50mm*50mm; The shape of the jet hole 102 is a frustum, and the upper surface of the frustum is parallel to the lower surface; The throat outlet 101 has a diameter of 1.5 mm; the throat inlet 103 has a diameter of 3 mm; The throat length of the converging jet hole 102 is 2mm. 4. The array plasma synthetic jet exciter of nanosecond pulse dielectric barrier discharge supercharging as claimed in claim 1, is characterized in that, The thickness of the electrode plate 20 is 0.01mm-1mm (preferably 0.05mm); The maximum diameter of the mesh of the electrode plate 20 is 2-5 mm (preferably 4 mm). 5. The array plasma synthetic jet exciter of nanosecond pulse dielectric barrier discharge supercharging as claimed in claim 4, is characterized in that, The thickness of the electrode plate 20 is 0.05mm; The maximum diameter of the mesh of the electrode plate 20 is 4mm; The electrode plate 20 is a dense square grid, a triangular grid, a honeycomb network, or a comb-like network. 6. The nanosecond pulse dielectric barrier discharge pressurized array plasma synthetic jet exciter as claimed in claim 1, wherein the insulating dielectric plate 30 adopts polyimide, nylon, acrylic, PPEK, pottery or mica, etc. Made of insulating material; when using thin film polyimide, the thickness range is 0.05-0.2mm; when using other materials, the thickness range is 0.5-2mm. 7. The nanosecond pulse dielectric barrier discharge pressurized array plasma synthetic jet actuator according to claim 1, characterized in that the thickness of the grounded metal plate 40 ranges from 2 to 4 mm. 8. the nanosecond pulse dielectric barrier discharge pressurized array plasma synthetic jet exciter as claimed in claim 1, is characterized in that, the depth of exciter cavity 105 is 1-4mm; The side wall thickness of top cover 10 is 4-10mm. 9. The working method of the array plasma synthetic jet device of nanosecond pulse dielectric barrier discharge supercharging, the device is based on the array plasma synthetic jet actuator of nanosecond pulse dielectric barrier discharge supercharging as claimed in claims 1 to 8, Wherein, the high-voltage output terminal of the high-voltage nanosecond pulse power supply 50 is connected to the electrode plate 20 through the lead wire 201, and the ground terminal is connected to the ground metal plate 40 through the lead wire 401; it is characterized in that, in one jet cycle, the complete working process includes three There are three stages: shock pressurization stage, array jet stage and porous suction recovery stage; step1, in the stage of impact boosting, the high-voltage nanosecond pulse power supply 50 outputs a high-voltage pulse and applies it on the electrode plate 20; because there is a tip effect and the electric field intensity is concentrated at each edge of the electrode plate 20, the first near the edge A discharge current column is generated; under the action of the rising edge of the high-voltage nanosecond pulse, the current column continues to expand outward along the direction of the electric field, forming a dielectric barrier discharge plasma area near the edge of the electrode; in this area, some gas molecules are ionized The incoming high-energy electrons continuously bombard other unionized gas molecules, producing a large number of excited state particles; these excited state particles release a large amount of heat during the extinguishing process, heating the temperature of the gas in the plasma region on a nanosecond time scale High-temperature gas is formed; due to the extremely short heating time scale, the high-temperature gas has no time to expand, so the pressure in the plasma region increases sharply, inducing the shock wave 106; the shock wave 106 propagates from the plasma region toward the surroundings, through continuous reflection and convergence, Raise the temperature and pressure of the entire exciter cavity 105 to a level much higher than atmospheric pressure; so far, the impact boosting stage is completed; Step 2. In the stage of jet array, driven by the high pressure inside the exciter cavity 105, high-temperature gas is ejected from the convergent jet hole 102 from the inside out to form a high-speed jet array 60, which is used for supersonic or other occasions Flow control; during the injection process of the jet, the pressure inside the actuator cavity 105 will continue to decrease; when the pressure inside the cavity 105 is less than or equal to the atmospheric pressure, the jet ends, the actuator starts to cool, and enters the porous suction recovery; Step 3. In the recovery stage of porous suction, the interior of the actuator cavity 105 begins to cool down, and the corresponding gas pressure gradually decreases; affected by the negative pressure difference inside and outside the jet throat, the suction flow 70 is formed; specifically, the outside of the actuator The normal-temperature, high-density gas is sucked into the interior of the exciter cavity 105 from the convergent jet hole array 102, and mixed with the expanded high-temperature, low-density gas to restore the exciter to its original working state; after complete recovery, the high-pressure The nanosecond pulse power supply 50 can output the next high-voltage pulse to realize the repetition frequency work of the exciter.

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