阅读说明：本技术 一种沿面介质阻挡放电等离子体流动控制性能优化的装置 (Device for optimizing flow control performance of surface dielectric barrier discharge plasma ) 是由 李婷 闫慧杰 俞思琦 于 2020-11-23 设计创作，主要内容包括：本发明属于大气压低温等离子体应用技术领域,涉及一种大气压沿面介质阻挡放电等离子体流动控制性能优化的装置及使用方法。所述的装置包括上电极、介质板、下电极、交流高压电源,所述的上、下电极采用方形铝箔电极,电极的宽度、长度可根据需求自行设计,介质板为微孔绝缘介质板,本发明中采用的是微孔氧化铝陶瓷介质板；上、下电极分别不对称粘在微孔氧化铝陶瓷介质板的上表面和下表面,且下电极被绝缘胶带覆盖；上电极作为高压电极,连接外界交流电源的高压端；下电极作为接地电极,与地线连接；所述的微孔氧化铝陶瓷介质板设有不少于一排水平微孔带。本发明能获得大扰动速度、强推力、高性能的等离子体流动控制能力。(The invention belongs to the technical field of application of atmospheric pressure low-temperature plasma, and relates to a device for optimizing flow control performance of atmospheric pressure surface dielectric barrier discharge plasma and a using method. The device comprises an upper electrode, a dielectric plate, a lower electrode and an alternating-current high-voltage power supply, wherein the upper electrode and the lower electrode adopt square aluminum foil electrodes, the width and the length of the electrodes can be designed according to requirements, the dielectric plate is a microporous insulating dielectric plate, and a microporous alumina ceramic dielectric plate is adopted in the invention; the upper electrode and the lower electrode are respectively and asymmetrically stuck on the upper surface and the lower surface of the microporous alumina ceramic dielectric plate, and the lower electrode is covered by an insulating tape; the upper electrode is used as a high-voltage electrode and is connected with a high-voltage end of an external alternating current power supply; the lower electrode is used as a grounding electrode and is connected with a ground wire; the microporous alumina ceramic dielectric plate is provided with at least one row of horizontal microporous belts. The invention can obtain the plasma flow control capability with large disturbance speed, strong thrust and high performance.)

1. A device for optimizing the flow control performance of a dielectric barrier discharge plasma along the surface is characterized by comprising an upper electrode, a dielectric plate, a lower electrode and an alternating-current high-voltage power supply; the upper electrode and the lower electrode adopt square aluminum foil electrodes (2), the width and the length of the electrode structure can be designed according to requirements, the dielectric plate is a micropore insulation dielectric plate, and the micropore insulation dielectric plate adopts one of a micropore alumina ceramic dielectric plate (1), an aluminum nitride ceramic plate or a quartz glass plate; the upper electrode and the lower electrode are respectively and asymmetrically stuck on the upper surface and the lower surface of the microporous alumina ceramic dielectric plate (1), and the lower electrode is covered by an insulating tape (4); the upper electrode is used as a high-voltage electrode and is connected with a high-voltage end of an external alternating current power supply; the lower electrode is used as a grounding electrode and is connected with a ground wire; the microporous alumina ceramic dielectric plate (1) is provided with at least one row of horizontal microporous belts (3);

the microporous belt (3) is parallel to the upper electrode; the distance between the upper electrode and the horizontal microporous belt (3) and the distance between the upper electrode and the lower electrode can be adjusted; the length of the microporous belt (3) is not less than the effective length of the upper electrode and the lower electrode; the number of micropores in the micropore belt (3) is not too small, and the length of 1mm is not less than 1 micropore.

2. An arrangement for optimizing the flow control performance of an in-plane dielectric barrier discharge plasma as claimed in claim 1, wherein the pitch of the mutually adjacent microholes in the microhole strip (3) is equal.

3. An arrangement for optimizing the flow control performance of an in-plane dielectric barrier discharge plasma as claimed in claim 1 or 2, wherein said aluminum foil electrode (2) is square and has four corners curved to prevent the generation of a point discharge.

4. An arrangement for optimizing the flow control of an edge-on dielectric barrier discharge plasma according to claim 1 or 2, characterized in that the width of the aluminum foil electrode (2) is adjustable and the electrode structure is a filament-like or zigzag-like electrode.

5. The apparatus for optimizing flow control of an edge-on dielectric barrier discharge plasma according to claim 1 or 2, wherein the frequency of the ac power source is selected according to the discharge requirement, and the peak-to-peak voltage is selected in a range of 13kV to 21 kV.

6. The apparatus for optimizing flow control of an edge-on-dielectric-barrier-discharge plasma of claim 3, wherein the AC power frequency is selected according to the discharge requirement, and the peak-to-peak voltage is selected in a range of 13kV to 21 kV.

7. The use method of the device for optimizing the flow control performance of the surface dielectric barrier discharge plasma according to any one of claims 1 to 7 is characterized by comprising the following steps:

designing positions of an electrode and a micropore belt;

step two, connecting a circuit: the upper electrode is connected with the high-voltage end of the alternating current power supply, and the lower electrode is grounded;

and thirdly, starting an alternating current power supply in an atmospheric pressure static environment to generate plasma with high disturbance speed, strong thrust and high flow control performance on the surface of the microporous alumina ceramic dielectric plate (1) of the device.

Technical Field

The invention belongs to the technical field of application of atmospheric pressure low-temperature plasma, and relates to a device for optimizing flow control performance of atmospheric pressure surface dielectric barrier discharge plasma and a using method.

Background

The object can receive the effect of resistance at the in-process that flows to movement obstruction produces noise, vibration, can lead to the unstability of object, deformation when more serious, and this problem is very outstanding in the aerospace field. In order to ensure stable operation of the aircraft, it becomes important to implement certain flow control for the aircraft.

The active flow control technology of the atmospheric pressure surface dielectric barrier discharge plasma has the advantages of no moving part, no change of the existing pneumatic appearance, light weight, simple structure, easy installation, high reaction speed, wide excitation frequency band, convenient real-time regulation and control of excitation parameters, low energy consumption and the like, and is concerned. Charged particles in the plasma accelerate under the action of an electric field and collide with neutral gas molecules to transfer momentum, electrohydrodynamic force is generated, airflow is induced to move directionally, ion wind is generated, and the plasma air generator has the capability of flow control. The lowest goal of the current flow control aiming at the subsonic speed is to realize the airflow control of the flow speed of 100m/s, and the flow control has practical application value because the take-off and landing speed of an aircraft can be reached at 100 m/s. However, the maximum induced gas flow velocity generated by the plasma of the dielectric barrier discharge along the surface is only 10.5m/s, which is far from enough for practical application, so that the performance of plasma flow control needs to be further improved.

Disclosure of Invention

Aiming at the limitation of improving the plasma flow control performance in the prior art, the invention provides a device for optimizing the flow control performance of an atmospheric pressure surface dielectric barrier discharge plasma and a using method thereof. The invention adopts a micropore dielectric barrier creeping discharge structure, can generate high-speed disturbance airflow compared with the conventional dielectric slab creeping discharge, and plays a certain advantage in the aspect of flow control performance.

The technical scheme of the invention is as follows:

a device for optimizing the flow control performance of a discharge plasma blocked by an edge dielectric can enhance discharge, can generate high-speed disturbance airflow compared with the edge discharge of a traditional dielectric plate, and comprises an upper electrode, a dielectric plate, a lower electrode and an alternating-current high-voltage power supply, wherein the upper electrode and the lower electrode adopt square aluminum foil electrodes, the width and the length of the electrodes can be designed according to requirements, the dielectric plate is a micropore insulation dielectric plate, and a micropore alumina ceramic dielectric plate is adopted in the invention; the upper electrode and the lower electrode are respectively and asymmetrically stuck on the upper surface and the lower surface of the microporous alumina ceramic dielectric plate, and the lower electrode is covered by an insulating tape; the upper electrode is used as a high-voltage electrode and is connected with a high-voltage end of an external alternating current power supply; the lower electrode is used as a grounding electrode and is connected with a ground wire; the microporous alumina ceramic dielectric plate is provided with at least one row of horizontal microporous belts. The electrode structure may also be a filamentary, serrated electrode.

The micropore strip is parallel to the upper electrode.

The distance between the upper electrode and the horizontal micropore belt and the distance between the upper electrode and the lower electrode can be adjusted.

The length of the micropore belt is not less than the effective length of the upper electrode and the lower electrode.

The centers of the pores adjacent to each other in the microporous belt are equal.

The number of micropores in the micropore belt is not too small, and the length of 1mm is not less than 1 micropore.

The aluminum foil electrode is square and four vertex angles are arc-shaped so as to prevent point discharge.

The width of the square aluminum foil electrode can be adjusted according to requirements.

The alternating current power supply frequency can be selected according to the discharge requirement, the voltage amplitude can be determined according to the distance between the upper electrode and the lower electrode and the thickness of the dielectric plate, the power supply frequency is 5kHz, and the voltage peak-to-peak value selection range is 13 kV-21 kV.

The method for controlling the flow of the plasma with high disturbance speed, strong thrust and high performance by adopting the device comprises the following steps:

designing positions of an electrode and a micropore belt;

step two, connecting a circuit: the upper electrode is connected with the high-voltage end of the alternating current power supply, and the lower electrode is grounded;

and thirdly, starting an alternating current power supply in an atmospheric pressure static environment to generate plasma with high disturbance speed, high thrust and high flow control performance on the surface of the microporous alumina ceramic dielectric plate of the device.

The artificially shot discharge image is stored as an experimental phenomenon, the capillary glass tube is connected with the pitot tube and the micro-pressure difference sensor to realize the measurement of the air flow and the air speed, the experimental device is placed on an electronic balance to measure the generated thrust, and the flow control capability is compared according to the measurement result.

The plasma flow control capability with large disturbance speed, strong thrust and high performance is obtained by adopting the device. By the device and the method, the frequency of the alternating current power supply used by the invention is 5kHz, and the plasma thrust generated by the micropore medium plate in the experiment can reach 1.83 times of the conventional medium plate thrust at most. The invention provides a breakthrough point for improving the flow control performance of the plasma of the surface dielectric barrier discharge.

The invention has the beneficial effects that:

the invention can obtain the plasma flow control capability with large disturbance speed, strong thrust and high performance. The method provides a way for realizing high-performance plasma flow control, and has important significance.

Drawings

FIG. 1 is a front view of a microporous alumina ceramic dielectric slab along-surface barrier discharge actuator device;

FIG. 2 is a top view of a microporous alumina ceramic dielectric slab along a surface barrier discharge actuator device;

FIG. 3 is a schematic circuit diagram of a microporous alumina ceramic dielectric slab along-surface barrier discharge device;

FIG. 4 is a schematic diagram of an experimental setup in which (a) is a microporous alumina ceramic dielectric slab discharge device; (b) a discharge device of a non-porous traditional alumina ceramic dielectric plate;

FIG. 5 is a discharge image of two discharge devices, wherein (a), (b) and (c) are discharge images of microporous alumina ceramic dielectric plates with peak-to-peak voltage values of 15kV, 16kV and 17kV, respectively; (d) discharge images of non-porous traditional alumina ceramic dielectric plates with voltage peak values of 15kV, 16kV and 17kV are respectively shown in (e) and (f);

FIG. 6 is the wind speed distribution of two devices along the surface of the dielectric slab when the peak voltage values are 15kV, 16kV and 17 kV;

FIG. 7 is a comparison of thrust produced by a microporous alumina ceramic dielectric sheet discharge and a non-porous conventional alumina ceramic dielectric sheet discharge;

FIG. 8 is a graph of discharge images of two devices of an aluminum nitride ceramic plate at a voltage peak-to-peak value of 15 kV;

FIG. 9 is a schematic view of an actuator device with a microporous belt on the lower electrode;

FIG. 10 shows the wind velocity distribution generated by the microporous belt on the lower electrode and the two devices along the surface of the dielectric plate, wherein the peak-to-peak voltages of (a) and (b) are 18kV and 21kV, respectively.

In the figure: 1, a microporous alumina ceramic dielectric plate; 2, an aluminum foil electrode; 3 a microporous belt; 4 insulating adhesive tape.

Detailed Description

The invention is further described below with reference to the accompanying drawings.

An apparatus for optimizing the flow control performance of an atmospheric pressure along-the-surface dielectric barrier discharge plasma, the apparatus comprising: upper electrode, micropore dielectric plate, lower electrode, alternating current high voltage power supply.

The upper electrode and the lower electrode are both square aluminum foil electrodes 2, and the dielectric plate adopts a microporous alumina ceramic dielectric plate 1; the upper electrode and the lower electrode are respectively and asymmetrically stuck on the upper surface and the lower surface of the microporous alumina ceramic dielectric plate 1, and the lower electrode is covered by an insulating tape 4; the upper electrode is used as a high-voltage electrode and is connected with a high-voltage end of an external alternating current power supply; the lower electrode is used as a grounding electrode and is connected with a ground wire; the microporous alumina ceramic dielectric plate 1 contains a microporous belt 3.

The method for controlling the flow of the plasma with high disturbance speed, strong thrust and high performance by adopting the device comprises the following steps:

firstly, designing the positions of the electrodes and the micropore belt, and assembling an experimental device. As shown in figure 1, an alumina ceramic dielectric plate is selected, wherein the total length of the microporous belt 3 is 50mm, the distance between the centers of adjacent microporous holes is 0.5mm, the widths of upper and lower electrodes are both 10mm, the effective lengths of the upper and lower electrodes are 54mm, the distance between the upper and lower electrodes is 3mm, and the microporous belt 3 is positioned between the upper and lower electrodes, arranged in parallel with the upper electrode and spaced from the upper electrode by 1 mm.

And secondly, connecting the circuit. As shown in fig. 3, the upper electrode is connected to the high voltage end of the ac power source, and the lower electrode is connected to the ground end of the ac power source.

And thirdly, starting a 5kHz alternating current power supply in an atmospheric pressure static environment, setting a voltage peak value of 15kV, and generating plasma with high disturbance speed, strong thrust and high flow control performance on the surface of a micropore dielectric plate of the device. The phenomenon of an experiment for artificially shooting a discharge image and storing the discharge image is solved, and the capillary glass tube is connected with a pitot tube and a micro-pressure difference sensor to measure the velocity of disturbance air flow generated by discharge.

And fourthly, regulating the peak value of the voltage to be 16kV and 17kV, repeating the experiment, and comparing the discharge experiment of the non-porous traditional dielectric plate under the same condition.

And fifthly, placing the device under the experimental conditions on an electronic balance to measure the thrust generated by discharge.

To demonstrate that the invention achieves the desired results and to highlight the beneficial results produced by the invention, comparative studies were carried out in experiments on two discharge structures (microporous dielectric sheet and non-porous conventional dielectric sheet):

experimental parameters: the width and the length of the upper electrode and the lower electrode can be adjusted at will, in order to avoid point discharge, four vertex angles of the square aluminum foil are cut into arc shapes, in figure 1 of the attached drawings of the specification, the width of the upper electrode and the width of the lower electrode are both 10mm, the length of the electrode is 54mm, the length of the electrode is approximate to the length of the micropore belt, the length of the electrode has no clear requirement, and the electrode is only required to be not longer than 8% of the length of the micropore belt and is as small as. The distance between the upper electrode and the lower electrode and the distance between the micropore and the upper electrode can also be adjusted, and the attached drawing of the specification adopts two conditions, wherein in one condition, the micropore belt is positioned between the upper electrode and the lower electrode, the distance between the upper electrode and the lower electrode is 3mm, and the distance between the upper electrode and the micropore is 1mm, as shown in figure 1; the other is that the micropore belt is positioned above the lower electrode, the distance between the upper electrode and the lower electrode is 1mm, and the distance between the upper electrode and the hole is 1mm, as shown in figure 9. The dielectric plate is made of insulating material, and the attached drawings in the specification comprise three dielectric plates and an alumina ceramic plate, and the specification is 80 multiplied by 60 multiplied by 1mm³The diameter of the micropore is 80 mu m, the distance between the centers of adjacent pores is 0.5mm, and the total length of the micropore belt is 50mm, wherein the dielectric plate corresponds to the figures 1-7; an aluminum nitride ceramic plate having a gauge of 65X 55X 0.5mm³The diameter of the micropore is 40 μm, the distance between adjacent hole centers is 1mm, and the total length of the micropore belt is 55mm, wherein the dielectric plate corresponds to the figure 8; a quartz glass plate having a thickness of 50X 1mm³The diameter of the micropore is 20 μm, the distance between adjacent hole centers is 0.5mm, the total length of the micropore belt is 20mm, and the pair of dielectric platesFig. 9 and 10 should be considered. Wherein the depth-diameter ratio of the micropores of the alumina ceramic dielectric plate is the same as that of the micropores of the aluminum nitride ceramic dielectric plate. The frequency of the adopted alternating current power supply is 5kHz, and the voltage peak value in the experiment is selected to be 13 kV-21 kV. The upper electrode and the lower electrode are respectively adhered with an aluminum foil strip, the aluminum foil strip is used as an interface for connecting the electrodes, and the upper electrode is used as a high-voltage electrode and is connected with a high-voltage end of an alternating current power supply; the lower electrode is used as a grounding electrode and is connected with a ground wire of an alternating current power supply. The experiment was carried out using a comparative method and a simplified apparatus is shown in FIG. 4.

Two discharge structure diagrams (a) and (b) in fig. 4 are different only in that there is no band of micro-holes in the ceramic dielectric sheet. FIG. 4 (a) is a microporous alumina ceramic dielectric slab; fig. 4 (b) is a non-porous conventional alumina ceramic dielectric plate. Discharge images of the two discharge structures were taken with a nikon D7000 digital camera, as shown in fig. 5. FIG. 5 is a discharge image of an oxidized ceramic plate with a micropore belt between upper and lower electrodes, wherein (a), (b), and (c) are discharge images of micropore dielectric plates with peak-to-peak voltages of 15kV, 16kV, and 17kV, respectively; (d) and (e) and (f) are discharge images of non-porous conventional dielectric plates with peak-to-peak voltage values of 15kV, 16kV and 17kV respectively.

As can be seen from fig. 5, the discharge of the microporous dielectric sheet is more uniform compared with the two devices, and the discharge filamentation of the non-porous conventional dielectric sheet is obvious. The observation of the bands of micropores also revealed an increase in the discharge at the micropores. Relevant research documents show that the flow control performance effect generated by uniform discharge is better than that of non-uniform filament discharge under the same experimental conditions.

Under the experimental conditions of fig. 5, the turbulent air flow velocity generated by the discharge was measured by connecting a pitot tube and a micro-differential pressure sensor with a capillary glass tube, and the measurement results are shown in fig. 6, in which (a), (b), and (c) are respectively 15kV, 16kV, and 17kV peak voltage values. It can be seen from the figure that the turbulent gas flow velocity generated by the discharge of the microporous dielectric plate is larger than that generated by the discharge of the non-porous conventional dielectric plate. When the voltage peak value is 17kV, the maximum disturbance air flow velocity of the discharge of the micropore medium plate can be improved by about 20 percent.

The thrust force generated by the discharge was also measured using an electronic balance, as shown in fig. 7. As can be seen from the figure, the thrust generated by the discharge of the microporous dielectric plate is larger than that generated by the nonporous traditional dielectric plate, the thrust measurement is the space total effect of the wind speed, and under the voltage peak value of 15kV, the thrust generated by the discharge of the microporous dielectric plate can be improved by about 40 percent compared with the thrust generated by the discharge of the nonporous traditional plate under the same condition. This also demonstrates the effective enhancement of the creeping discharge plasma flow control performance of the microporous dielectric plate.

In addition, under the condition of ensuring that the depth-diameter ratio of the micropores is not changed, the thickness of the dielectric plate is reduced, the experiment is repeated by adopting the aluminum nitride ceramic dielectric plate with the thickness of 0.5mm, and the discharge image is shown in fig. 8. Wherein a is a micropore dielectric plate discharge image, and b is a nonporous conventional dielectric plate discharge image. As is more evident from fig. 8: the discharge generated by the micropore medium plate is more uniform, the discharge is generated at the micropore, and the discharge at the micropore is enhanced. The generated thrust was measured using a balance, and it was found that the thrust at peak voltage values of 13kV and 14kV was increased by about 83% and 64%, respectively, as compared with the discharge of a conventional dielectric plate without a hole, and the flow control performance under this experimental condition was better.

The position of the micropore belt is changed, an experiment that the micropore belt is positioned on the lower electrode is carried out, the drawing of an exciter device is shown in fig. 9, a dielectric plate is made of quartz glass and is 1mm thick, the diameter of each micropore is 20 microns, the micropore belt is positioned on the lower electrode, the distance between the upper electrode and the lower electrode is 1mm, and the distance between the upper electrode and the lower electrode is 1 mm. The disturbing gas flow velocity generated by discharge is shown in FIG. 10, and (a) and (b) are respectively 18kV and 21kV of peak voltage, and it can be seen that the disturbing gas flow velocity generated by discharge is still large as that of the microporous dielectric sheet.

In summary, under the same experimental conditions, the discharge of the microporous dielectric plate can be compared with the discharge of the non-porous conventional dielectric plate to draw the conclusion that:

(1) the discharge along the surface of the micropore medium plate is more uniform;

(2) the disturbance airflow speed generated by the surface discharge of the micropore medium plate is higher, and the generated thrust is stronger;

(3) when the depth-diameter ratio of the micropores is fixed, the flow control performance of the thin aluminum nitride ceramic dielectric plate is better than that of the thick aluminum oxide ceramic dielectric plate;

(4) by adjusting the position of the pores, the flow control performance generated by the exciter is still better than that of a non-porous traditional medium plate.

The research shows that the thrust generated by the discharge of the microporous dielectric plate can be maximally improved by about 83 percent compared with the thrust generated by the discharge of the nonporous dielectric plate. The invention introduces the microporous belt into the traditional medium plate, improves the disturbance air flow speed and the thrust and enhances the plasma flow control capability.

On the basis of the invention, the flow control capability with better effect can be obtained by punching a plurality of rows of microporous belts on the upper medium plate, adjusting the distance between the microporous belts and the upper and lower electrodes or adjusting the depth-diameter ratio of the micropores.

The shape and width of the upper and lower electrodes also have an influence on the flow control performance of the actuator device, and the description only adopts the most common electrode shape and width, and the comparison shows that the microporous belt has an improvement effect on the flow control performance.

The examples are only for showing the embodiments of the present invention, but not for limiting the scope of the patent of the present invention, it should be noted that, for those skilled in the art, many variations and modifications can be made without departing from the concept of the present invention, and these are all within the scope of the protection of the present invention.