Plasma discharge equipment capable of generating stride-over type induced eddy current and use method of plasma discharge equipment

Abstract

The invention relates to plasma discharge equipment capable of generating spanning type induced vortexes and a use method of the plasma discharge equipment, and belongs to the technical field of active flow control. Vortex continuously generated by pulse modulation is promoted to periodically have higher convection speed and momentum flux on the basis of original characteristics, a traditional surface dielectric barrier discharge single-machine layout mode is broken, the limitation of existing plasma induced airflow in the aspect of flow control is solved, better flow control performance is achieved, and the service life of the surface dielectric barrier discharge device is prolonged. And better service performance is achieved in the aspects of flow separation, vortex rupture and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of active flow control, and in particular to a plasma discharge device for generating a leaping induced vortex and a use method thereof. Background Art

[0002] When a fluid flows on the surface or inside an object, it is easy to form unstable boundary layers, separated flows, shedding vortices and other phenomena due to factors such as pressure gradients and velocity gradients, which have certain negative effects in practical applications. In order to change the flow characteristics of the fluid, active flow control is one of the main methods. This method introduces additional airflow through a certain amount of energy consumption, so that it couples with the original flow, thereby improving or suppressing the original flow structure.

[0003] Surface dielectric barrier discharge equipment is widely used in active flow control due to its simple structure, high robustness, easy control and low power. The plasma induced airflow it generates can achieve effective control of boundary layer instability, wing separation flow, blunt body shedding vortex and other aspects.

[0004] At present, the generation methods of surface dielectric barrier discharge include continuous induced airflow with continuous excitation and pulse induced airflow with signal modulation. Continuous induced airflow generally has a higher speed and momentum flux, but a smaller effective range and vortex flux. On the contrary, pulse induced airflow has a higher effective range and vortex flux, but a smaller speed and momentum flux. It can be seen that the actual performance of surface dielectric barrier discharge equipment in the prior art in terms of flow control is relatively low and the application range is narrow. At present, there is no device that generates a plasma induced airflow that has a higher speed, momentum flux, and a higher effective range and vortex flux at the same time. Summary of the invention

[0005] In view of the above problems, the present invention provides a discharge device for generating a leaping plasma-induced vortex and a method for using the device, which utilizes the interaction between multiple pairs of vortices to form a vortex-crossing phenomenon, so that the vortices continuously generated by pulse modulation periodically have higher convection speed and momentum flux on the basis of their original characteristics, breaking the traditional single-machine layout of surface dielectric barrier discharge, solving the limitations of existing plasma-induced airflow in flow control, having better flow control performance, and having better service performance in terms of control of flow separation, vortex breakage, etc.

[0006] The present invention provides a dielectric barrier discharge device for leapfrogging plasma-induced eddy current, comprising:

[0007] An insulating plate 1 and a discharge device 1 and a discharge device 2 placed at two ends of the insulating plate in a manner of facing each other;

[0008] In one embodiment of the present invention, the discharge device 1 includes an exposed electrode 2, an insulating medium 4 and a packaged electrode 3;

[0009] The second discharge device comprises a second exposed electrode, a second insulating medium and a second packaged electrode;

[0010] The packaged electrode 1 is arranged on a side of the interior of the insulating medium 1 close to the end of the insulating plate; the exposed electrode 1 is arranged on a side of the exterior of the insulating medium 1 away from the end of the insulating plate;

[0011] The second packaged electrode is arranged on a side of the inside of the second insulating medium close to the discharge end of the insulating plate; the second exposed electrode is arranged on a side of the outside of the second insulating medium away from the discharge end of the insulating plate;

[0012] The packaged electrode 1 and the packaged electrode 2 are substantially concentrically arranged on the outside of the insulating plate; the end of the packaged electrode 1 3 is aligned with the end of the insulating plate 1; the end of the packaged electrode 2 is aligned with the end of the insulating plate 1;

[0013] The exposed electrode 1 and the exposed electrode 2 are substantially concentrically arranged outside the insulating medium 1 and the insulating medium 2;

[0014] The length ratio of the package electrode 1, the exposed electrode 1, the insulating medium 1 and the insulating plate is 1:1:2:4;

[0015] Preferably, the relative dielectric constant of the insulating medium 4 is 2-6;

[0016] Exemplarily, the insulating plate 1 is acrylic glass; the exposed electrode 1 2 , the exposed electrode 2 , the packaged electrode 1 3 and the packaged electrode 2 are all copper foils; the insulating medium 1 4 and the insulating medium 2 are polyimide films.

[0017] Preferably, the discharge device 1 and the discharge device 2 are surface dielectric barrier discharge device 1 and surface dielectric barrier discharge device 2 respectively;

[0018] Another object of the present invention is to provide a method for using a plasma discharge device for generating a leaping plasma induced vortex, comprising:

[0019] Using voltage to drive the dielectric barrier discharge device; the voltage is a high-frequency and high-amplitude AC voltage;

[0020] Preset modulation frequency and excitation voltage source;

[0021] The excitation voltage source is connected to the signal generator, and based on the preset modulation frequency, outputs a periodic excitation voltage. Based on the periodic excitation voltage, the discharge device 1 and the discharge device 2 periodically generate discharges. During the discharge process, the discharge device 1 and the discharge device 2 periodically generate multiple groups of counter-rotating eddy current pairs, and multiple groups of leapfrogging plasma vortex structures are formed based on the multiple groups of counter-rotating eddy current pairs.

[0022] Preferably, the signal generator is a square wave signal generator, a sine wave signal generator or a triangle wave signal generator;

[0023] In the present invention, after the excitation voltage source is connected to the signal generator, a periodic excitation voltage is output based on a preset modulation frequency. Based on the periodic excitation voltage, the air around the discharge device 1 and the discharge device 2 is ionized to generate ions 1 and 2. The ions 1 and 2 move under the action of the electric field, and transfer momentum to the adjacent molecules 1 and 2 respectively, forming induced velocities 1 and 2 emitted from the discharge device 1 and the discharge device 2 in the horizontal direction. The molecules 1 and 2 continuously move backward in the horizontal direction according to the induced velocities 1 and 2, respectively prompting the surrounding molecules of the molecules 1 and 2 to move toward the middle to maintain the continuity of the air medium, thereby forming reverse rotational motions, obtaining counterclockwise rotating vortices and clockwise rotating vortices, and forming corresponding counter-rotating vortex pairs based on the counterclockwise rotating vortices and the clockwise rotating vortices; the dielectric barrier discharge device periodically generates multiple groups of counter-rotating vortex pairs, and forms multiple groups of leapfrogging plasma vortex structures based on the multiple groups of counter-rotating vortex pairs.

[0024] Preferably, the amplitude of the excitation voltage can ionize the air to form a discharge without breaking down the insulating medium; the excitation frequency of the excitation voltage is above kHz;

[0025] Preferably, during the discharge process, multiple groups of counter-rotating eddy current pairs are generated, wherein every two groups of counter-rotating eddy current pairs constitute a cycle, that is, multiple groups of counter-rotating eddy current pairs are periodically generated during the discharge process; the two groups of counter-rotating eddy current pairs generated in each cycle form a leaping plasma vortex structure;

[0026] It can be understood that the leaping plasma vortex structure is that two groups of counter-rotating vortex pairs leap over each other.

[0027] Exemplarily, the leaping plasma vortex structure includes: a vortex pair 1 51 and a vortex pair 2 52; the vortex pair 1 51 and the vortex pair 2 52 are adjacent vortex pairs;

[0028] Furthermore, the adjacent vortex pair one 51 and vortex pair two 52 produce an inter-vortex effect. The induced velocity of vortex pair one 51 reduces the distance between the counterclockwise rotating vortex P2 and the clockwise rotating vortex N2 in vortex pair two 52, and enhances the convection velocity of the counterclockwise rotating vortex P2 and the clockwise rotating vortex N2 in vortex pair two 52. On the contrary, the induced velocity of vortex pair two 52 increases the distance between the counterclockwise rotating vortex P1 and the clockwise rotating vortex N1 in vortex pair one 51, and reduces the convection velocity of the counterclockwise rotating vortex P1 and the clockwise rotating vortex N1 in vortex pair one 51, thereby forming a convection velocity difference between vortex pair one and vortex pair two. Based on the convection velocity difference, vortex pair two 52 catches up with and crosses vortex pair one 51.

[0029] Furthermore, according to the Biot-Savart law, two adjacent vortex pairs produce inter-vortex effects, vortex pair one 51 is the front vortex, and vortex pair two 52 is the rear vortex; the induced velocity of the front vortex reduces the inter-vortex distance h2 between the counterclockwise rotating vortex P2 and the clockwise rotating vortex N2 in the rear vortex, thereby enhancing the vortex convection velocity of the rear vortex; on the contrary, the induced velocity of the rear vortex increases the vortex distance h1 between the counterclockwise rotating vortex P1 and the clockwise rotating vortex N1 in the front vortex, thereby reducing the vortex convection velocity of the front vortex; the convection velocity difference between the vortex pairs causes the rear vortex to gradually approach the front vortex until the rear vortex exceeds the front vortex, completing the crossing behavior, and the spatial positions of the front vortex and the rear vortex are interchanged, preparing for the next crossing behavior; as Figure 2 ;

[0030] Exemplarily, the vortex pair 2 52 includes a vortex P2 rotating counterclockwise and a vortex N2 rotating clockwise;

[0031] The vortex pair 51 includes a vortex P1 rotating counterclockwise and a vortex N1 rotating clockwise;

[0032] The ratio of the convection velocity of the counterclockwise rotating vortex P2 and the clockwise rotating vortex N2 in the vortex pair 2 52 to the convection velocity of the counterclockwise rotating vortex P1 and the clockwise rotating vortex N1 in the vortex pair 1 51 is greater than 1, forming a convection velocity difference between the vortex pairs.

[0033] In one embodiment of the present invention, the leaping plasma vortex structure includes vortex pair one and vortex pair two; the circulation in vortex pair one and vortex pair two reaches a maximum value at the same increasing rate, and then the circulation decays.

[0034] Furthermore, the circulation decay rate in the vortex pair one is less than the circulation decay rate in the vortex pair two;

[0035] The ratio of the circulation attenuation rate of the second vortex pair to the circulation attenuation rate of the first vortex pair is greater than 1, forming a convective velocity difference between the vortex pairs. ;

[0036] Furthermore, the expressions for the circulation in the vortex pair one and the vortex pair two in the leaping plasma vortex structure are:

[0037] Γ * =Γ0 / x0U0

[0038] Among them, Γ * is the dimensionless starting vortex circulation of the leapfrogging plasma vortex structure, U0 is the initial convection velocity between vortex pair one and vortex pair two, x0 is the initial convection distance between vortex pair one and vortex pair two, and Γ0 is the initial circulation intensity of vortex pair one or vortex pair two.

[0039] Furthermore, the present invention also includes a dimensionless time for forming a leaping plasma vortex structure, expressed as:

[0040] T * =tU0 2 / v

[0041] Among them, T * is the dimensionless time for the formation of the leaping plasma vortex structure, t is the discharge time, U0 is the initial convection velocity between vortex pair one and vortex pair two, and v is the kinematic viscosity of the air.

[0042] The leaping plasma vortex structure of the present invention realizes periodic leaping motion. In the leaping plasma vortex structure, the distance between vortices in the front vortex pair (front vortex pair) increases due to the vortex induced velocity of the second vortex pair (rear vortex pair), and the convection velocity of the corresponding vortex pair decreases; while the distance between vortices in the rear vortex pair decreases due to the induced airflow of the front vortex pair, and the convection velocity is greater than that of the front vortex pair. Accordingly, the speed difference between the two vortex pairs makes the rear vortex pair constantly catch up with the front vortex pair, completing the chasing, leaping and surpassing behaviors within a certain period of time.

[0043] The spanning behavior between the double vortex pairs in the spanning plasma vortex structure of the present invention is accompanied by strong turbulent kinetic energy and Reynolds stress, which effectively enhances the momentum and vortex exchange between the vortex pairs, and correspondingly generates strong momentum and vortex flux, which can enhance the flow control performance of the plasma induced airflow.

[0044] Compared with the prior art, the present invention has at least the following beneficial effects:

[0045] (1) The present invention can periodically generate a leap-forward continuous reverse vortex pair by symmetrically placing two discharge devices and adopting a selected excitation method. The leap-forward continuous reverse vortex pair has a high speed, effective range, momentum flux and vortex flux, and can achieve a better flow control effect;

[0046] (2) The speed and frequency of the leaping eddy current generated by the present invention are controlled by the excitation voltage and the modulation signal respectively, and can produce a periodic eddy current leaping phenomenon with a higher speed and frequency;

[0047] (3) The device of the present invention is composed of electrodes with micron-level thickness, insulating media and insulating plates with millimeter-level thickness. It does not require any large-scale power loading system, has a simple overall structure and is easy to modulate. It can be arranged on an object without changing the external structure of the object to achieve active flow control. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] The drawings are only for the purpose of illustrating particular embodiments and are not to be construed as limiting the invention.

[0049] Figure 1 Schematic diagram of a leaping plasma induced vortex generating device in an embodiment of the present invention;

[0050] Figure 2 A diagram showing the formation process of a leaping plasma-induced vortex in an embodiment of the present invention;

[0051] Figure 3 A schematic diagram of key parameter values ​​for forming a leaping plasma-induced vortex in an embodiment of the present invention;

[0052] Figure 4 Schematic diagram of the characteristics of leapfrogging plasma-induced vortex motion in an embodiment of the present invention;

[0053] Figure 5 Schematic diagram of the change of the vortex circulation induced by leaping plasma in an embodiment of the present invention;

[0054] Figure 6 It is a comparison diagram of the leap-forward plasma induced vortex characteristics in the embodiments of the present invention.

[0055] Reference numerals:

[0056] 1 insulating plate, 2 exposed electrode, 3 encapsulated electrode, 4 insulating medium, 51 eddy current pair 1, 52 eddy current pair 2 DETAILED DESCRIPTION

[0057] In order to more clearly understand the above-mentioned purpose, features and advantages of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other. In addition, the present invention can also be implemented in other ways different from those described herein, and therefore, the protection scope of the present invention is not limited by the specific embodiments disclosed below.

[0058] A specific embodiment of the present invention, as Figure 1-6In order to illustrate the effectiveness of the method proposed in the present invention, the above technical solution of the present invention is described in detail below through a specific embodiment, and the specific implementation steps are as follows:

[0059] The present invention provides a dielectric barrier discharge device for leapfrogging plasma-induced eddy current, comprising:

[0060] An insulating plate 1 and a discharge device 1 and a discharge device 2 placed at two ends of the insulating plate in a manner of facing each other;

[0061] In one embodiment of the present invention, the discharge device 1 includes an exposed electrode 2, an insulating medium 4 and a packaged electrode 3;

[0062] The second discharge device comprises a second exposed electrode, a second insulating medium and a second packaged electrode;

[0063] The packaged electrode 1 is arranged on a side of the interior of the insulating medium 1 close to the end of the insulating plate; the exposed electrode 1 is arranged on a side of the exterior of the insulating medium 1 away from the end of the insulating plate;

[0064] The second packaged electrode is arranged on a side of the inside of the second insulating medium close to the discharge end of the insulating plate; the second exposed electrode is arranged on a side of the outside of the second insulating medium away from the discharge end of the insulating plate;

[0065] The packaged electrode 1 and the packaged electrode 2 are substantially concentrically arranged on the outside of the insulating plate; the end of the packaged electrode 1 3 is aligned with the end of the insulating plate 1; the end of the packaged electrode 2 is aligned with the end of the insulating plate 1;

[0066] The exposed electrode 1 and the exposed electrode 2 are substantially concentrically arranged outside the insulating medium 1 and the insulating medium 2;

[0067] The length ratio of the package electrode 1, the exposed electrode 1, the insulating medium 1 and the insulating plate is 1:1:2:4;

[0068] Preferably, the relative dielectric constant of the insulating medium 4 is 2-6;

[0069] Exemplarily, the insulating plate 1 is acrylic glass; the exposed electrode 1 2 , the exposed electrode 2 , the packaged electrode 1 3 and the packaged electrode 2 are all copper foils; the insulating medium 1 4 and the insulating medium 2 are polyimide films.

[0070] Preferably, the discharge device 1 and the discharge device 2 are surface dielectric barrier discharge device 1 and surface dielectric barrier discharge device 2 respectively;

[0071] Another object of the present invention is to provide a method for using a plasma discharge device for generating a leaping plasma induced vortex, comprising:

[0072] Using voltage to drive the dielectric barrier discharge device; the voltage is a high-frequency and high-amplitude AC voltage;

[0073] Preset modulation frequency and excitation voltage source;

[0074] The excitation voltage source is connected to the signal generator, and based on the preset modulation frequency, outputs a periodic excitation voltage. Based on the periodic excitation voltage, the discharge device 1 and the discharge device 2 periodically generate discharges. During the discharge process, the discharge device 1 and the discharge device 2 periodically generate multiple groups of counter-rotating eddy current pairs, and multiple groups of leapfrogging plasma vortex structures are formed based on the multiple groups of counter-rotating eddy current pairs.

[0075] Preferably, the signal generator is a square wave signal generator, a sine wave signal generator or a triangle wave signal generator;

[0076] In the present invention, after the excitation voltage source is connected to the signal generator, a periodic excitation voltage is output based on a preset modulation frequency. Based on the periodic excitation voltage, the air around the discharge device 1 and the discharge device 2 is ionized to generate ions 1 and 2. The ions 1 and 2 move under the action of the electric field, and transfer momentum to the adjacent molecules 1 and 2 respectively, forming induced velocities 1 and 2 emitted from the discharge device 1 and the discharge device 2 in the horizontal direction. The molecules 1 and 2 continuously move backward in the horizontal direction according to the induced velocities 1 and 2, respectively prompting the surrounding molecules of the molecules 1 and 2 to move toward the middle to maintain the continuity of the air medium, thereby forming reverse rotational motions, obtaining counterclockwise rotating vortices and clockwise rotating vortices, and forming corresponding counter-rotating vortex pairs based on the counterclockwise rotating vortices and the clockwise rotating vortices; the dielectric barrier discharge device periodically generates multiple groups of counter-rotating vortex pairs, and forms multiple groups of leapfrogging plasma vortex structures based on the multiple groups of counter-rotating vortex pairs.

[0077] Preferably, the amplitude of the excitation voltage can ionize the air to form a discharge without breaking down the insulating medium; the excitation frequency of the excitation voltage is above kHz;

[0078] Preferably, during the discharge process, multiple groups of counter-rotating eddy current pairs are generated, wherein every two groups of counter-rotating eddy current pairs constitute a cycle, that is, multiple groups of counter-rotating eddy current pairs are periodically generated during the discharge process; the two groups of counter-rotating eddy current pairs generated in each cycle form a leaping plasma vortex structure;

[0079] It can be understood that the leaping plasma vortex structure is that two groups of counter-rotating vortex pairs leap over each other.

[0080] Exemplarily, the leaping plasma vortex structure includes: a vortex pair 1 51 and a vortex pair 2 52; the vortex pair 1 51 and the vortex pair 2 52 are adjacent vortex pairs;

[0081] Furthermore, the adjacent vortex pair one 51 and vortex pair two 52 produce an inter-vortex effect. The induced velocity of vortex pair one 51 reduces the distance between the counterclockwise rotating vortex P2 and the clockwise rotating vortex N2 in vortex pair two 52, and enhances the convection velocity of the counterclockwise rotating vortex P2 and the clockwise rotating vortex N2 in vortex pair two 52. On the contrary, the induced velocity of vortex pair two 52 increases the distance between the counterclockwise rotating vortex P1 and the clockwise rotating vortex N1 in vortex pair one 51, and reduces the convection velocity of the counterclockwise rotating vortex P1 and the clockwise rotating vortex N1 in vortex pair one 51, thereby forming a convection velocity difference between vortex pair one and vortex pair two. Based on the convection velocity difference, vortex pair two 52 catches up with and crosses vortex pair one 51.

[0082] Furthermore, according to the Biot-Savart law, two adjacent vortex pairs produce inter-vortex effects, vortex pair one 51 is the front vortex, and vortex pair two 52 is the rear vortex; the induced velocity of the front vortex reduces the inter-vortex distance h2 between the counterclockwise rotating vortex P2 and the clockwise rotating vortex N2 in the rear vortex, thereby enhancing the vortex convection velocity of the rear vortex; on the contrary, the induced velocity of the rear vortex increases the vortex distance h1 between the counterclockwise rotating vortex P1 and the clockwise rotating vortex N1 in the front vortex, thereby reducing the vortex convection velocity of the front vortex; the convection velocity difference between the vortex pairs causes the rear vortex to gradually approach the front vortex until the rear vortex exceeds the front vortex, completing the crossing behavior, and the spatial positions of the front vortex and the rear vortex are interchanged, preparing for the next crossing behavior; as Figure 2 ;

[0083] Exemplarily, the vortex pair 2 52 includes a vortex P2 rotating counterclockwise and a vortex N2 rotating clockwise;

[0084] The vortex pair 51 includes a vortex P1 rotating counterclockwise and a vortex N1 rotating clockwise;

[0085] The ratio of the convection velocity of the counterclockwise rotating vortex P2 and the clockwise rotating vortex N2 in the vortex pair 2 52 to the convection velocity of the counterclockwise rotating vortex P1 and the clockwise rotating vortex N1 in the vortex pair 1 51 is greater than 1, forming a convection velocity difference between the vortex pairs.

[0086] In one embodiment of the present invention, the leaping plasma vortex structure includes vortex pair one and vortex pair two; the circulation in vortex pair one and vortex pair two reaches a maximum value at the same increasing rate, and then the circulation decays.

[0087] Furthermore, the circulation decay rate in the vortex pair one is less than the circulation decay rate in the vortex pair two;

[0088] The ratio of the circulation attenuation rate of the second vortex pair to the circulation attenuation rate of the first vortex pair is greater than 1, forming a convective velocity difference between the vortex pairs. ;

[0089] Furthermore, the expressions for the circulation in the vortex pair one and the vortex pair two in the leaping plasma vortex structure are:

[0090] Γ * =Γ0 / x0U0

[0091] Among them, Γ * is the dimensionless starting vortex circulation of the leapfrogging plasma vortex structure, U0 is the initial convection velocity between vortex pair one and vortex pair two, x0 is the initial convection distance between vortex pair one and vortex pair two, and Γ0 is the initial circulation intensity of vortex pair one or vortex pair two.

[0092] Furthermore, the present invention also includes a dimensionless time for forming a leaping plasma vortex structure, expressed as:

[0093] T * =tU0 2 / v

[0094] Among them, T * is the dimensionless time for the formation of the leaping plasma vortex structure, t is the discharge time, U0 is the initial convection velocity between vortex pair one and vortex pair two, and v is the kinematic viscosity of the air.

[0095] The leaping plasma vortex structure of the present invention realizes periodic leaping motion. In the leaping plasma vortex structure, the distance between vortices in the front vortex pair (front vortex pair) increases due to the vortex induced velocity of the second vortex pair (rear vortex pair), and the convection velocity of the corresponding vortex pair decreases; while the distance between vortices in the rear vortex pair decreases due to the induced airflow of the front vortex pair, and the convection velocity is greater than that of the front vortex pair. Accordingly, the speed difference between the two vortex pairs makes the rear vortex pair constantly catch up with the front vortex pair, completing the chasing, leaping and surpassing behaviors within a certain period of time.

[0096] The spanning behavior between the double vortex pairs in the spanning plasma vortex structure of the present invention is accompanied by strong turbulent kinetic energy and Reynolds stress, which effectively enhances the momentum and vortex exchange between the vortex pairs, and correspondingly generates strong momentum and vortex flux, which can enhance the flow control performance of the plasma induced airflow.

[0097] Embodiment 1

[0098] A dielectric barrier discharge device for generating a leaping plasma induced eddy current comprises an insulating plate 1, an exposed electrode 2, a packaged electrode 3 and an insulating medium 4; specifically, the insulating plate 1 is an acrylic organic glass with a thickness of 3 mm, the exposed electrode 2 and the packaged electrode 3 are both copper foils with a thickness of 0.05 mm and a width of 100 mm, and the insulating medium 4 is a polyimide film with a thickness of 0.15 mm and a width of 200 mm.

[0099] The device is excited by sinusoidal alternating current with a peak-to-peak voltage of 18kV and a frequency of 7kHz. Its pulse modulation signal is a square wave with a duty cycle of 50% and a modulation frequency range from 8Hz to 160Hz.

[0100] After the device is driven by the excitation voltage, it continuously generates counter-rotating vortex pairs. At modulation frequencies such as 40Hz and 60Hz, the vortex pairs of every two pulse cycles form a leaping plasma vortex structure; under the mutual influence of the vortex induced velocity, the front vortex pair (vortex pair 1) moves linearly along the flow direction, accompanied by the expansion of the vortex distance between the counterclockwise rotating vortex P1 and the clockwise rotating vortex N1, while the rear vortex pair also moves linearly along the flow direction, but the vortex distance between the counterclockwise rotating vortex P2 and the clockwise rotating vortex N2 decreases, forming a convective velocity difference between the vortex pairs, so that the rear vortex pair gradually catches up with the front vortex pair, such as Figure 2 As shown in FIG. 1 ; the rear vortex pair completes the leaping behavior between the front vortex pair, and then the spatial positions of the front and rear vortex pairs are exchanged to prepare for the next leaping behavior, completing the chasing-leaping-surpassing behavior within two pulse cycles; as shown in FIG. Figure 4 ;

[0101] Among them, the convection speed of vortex pair two is 1.7 times that of vortex pair one.

[0102] When the peak-to-peak value of the excitation voltage is 18 kV and the frequency is 7 kHz, the pulse modulation frequency corresponding to the leaping plasma vortex structure is between 8 Hz and 160 Hz; the time T * Between (100, 240); circulation parameter Γ * Between (6, 9); Too large Γ * The excessively large T * This causes the vortex pairs to develop independently due to weak interactions.

[0103] The circulation volume of the periodically leapfrogging plasma vortex structure changes as follows Figure 5 As shown, the double vortex pairs show the same growth trend after being generated, that is, they obtain the maximum vortex intensity at the same growth rate in the same time, but the subsequent vortex attenuation is significantly different due to the crossing behavior; specifically, the circulation attenuation rate of the rear vortex pair is 1.5 times that of the front vortex pair.

[0104] Comparison of the characteristics of continuous, leapfrogging and pulsed plasma vortex structures Figure 6 As shown; specifically, the leaping plasma vortex structure has a strong velocity amplitude, effective range, momentum flux and vortex flux, which can effectively improve the service performance of the plasma induced airflow in flow control.

[0105] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. A plasma discharge device for generating a leaping plasma induced vortex, characterized in that: It comprises an insulating plate (1) and a discharge device 1 and a discharge device 2 which are placed at two ends of the insulating plate in a manner of facing each other; The discharge device comprises an exposed electrode (2), an insulating medium (4) and a packaged electrode (3); The second discharge device comprises a second exposed electrode, a second insulating medium and a second packaged electrode; The packaged electrode 1 and the packaged electrode 2 are basically concentrically arranged on the outside of the insulating plate; the exposed electrode 1 and the exposed electrode 2 are basically concentrically arranged on the outside of the insulating medium 1 and the insulating medium 2; The end of the packaged electrode 1 (3) and the end of the packaged electrode 2 are respectively aligned with the end of the insulating plate (1).

2. The plasma discharge device for generating a leaping plasma induced vortex according to claim 1, characterized in that: The packaged electrode 1 is arranged on a side of the interior of the insulating medium 1 close to the end of the insulating plate; the exposed electrode 1 is arranged on a side of the exterior of the insulating medium 1 away from the end of the insulating plate; the packaged electrode 2 is arranged on a side of the interior of the insulating medium 2 close to the discharge end of the insulating plate; the exposed electrode 2 is arranged on a side of the exterior of the insulating medium 2 away from the discharge end of the insulating plate.

3. The plasma discharge device for generating a leaping plasma induced vortex according to claim 1, characterized in that: The length ratio of the packaged electrode 1, the exposed electrode 1, the insulating medium 1 and the insulating plate is 1:1:2:

4.

4. The plasma discharge device for generating a leaping plasma induced vortex according to claim 1, characterized in that: The insulating plate (1) is acrylic organic glass; the exposed electrode 1 (2), the exposed electrode 2, the packaged electrode 1 (3) and the packaged electrode 2 are all copper foils; the insulating medium 1 and the insulating medium 2 (4) are polyimide films.

5. A method for using a plasma discharge device for generating a leaping plasma induced vortex, using the plasma discharge device according to any one of claims 1 to 4, characterized in that: include: Using voltage to drive the dielectric barrier discharge device; Preset modulation frequency and excitation voltage source; The excitation voltage source is connected to the signal generator, and based on the preset modulation frequency, a periodic excitation voltage is outputted. Based on the periodic excitation voltage, discharge device one and discharge device two generate discharges periodically. During the discharge process, discharge device one and discharge device two generate multiple groups of counter-rotating eddy current pairs, and multiple groups of leaping plasma vortex structures are formed based on the multiple groups of counter-rotating eddy current pairs.

6. The method for using the plasma discharge device according to claim 5, characterized in that: The voltage is an alternating current voltage with a high frequency and a high amplitude; the signal generator is a square wave signal generator, a sine wave signal generator or a triangle wave signal generator.

7. The method for using the plasma discharge device according to claim 5, characterized in that: During the discharge process, discharge device 1 and discharge device 2 generate multiple groups of counter-rotating vortex pairs, wherein every two groups of counter-rotating vortex pairs constitute a cycle; and the two groups of counter-rotating vortex pairs generated in each cycle form a leaping plasma vortex structure.

8. The method for using the plasma discharge device according to claim 5, characterized in that: The leaping plasma vortex structure comprises a vortex pair one (51) and a vortex pair two (52); the circulation in the vortex pair one (51) and the vortex pair two (52) reaches a maximum value at the same increasing rate, and then the circulation decays.

9. The method for using the plasma discharge device according to claim 8, characterized in that: The vortex pair two (52) includes a vortex P2 rotating counterclockwise and a vortex N2 rotating clockwise; The vortex pair (51) includes a vortex P1 rotating counterclockwise and a vortex N1 rotating clockwise; The ratio of the convective velocity of the counterclockwise rotating vortex P2 and the clockwise rotating vortex N2 in the vortex pair 2 (52) to the convective velocity of the counterclockwise rotating vortex P1 and the clockwise rotating vortex N1 in the vortex pair 1 (51) is greater than 1, forming a convective velocity difference between the vortex pairs.

10. The method for using the plasma discharge device according to claim 8, characterized in that: The expression of the circulation in the vortex pair one and the vortex pair two in the leaping plasma vortex structure is: C * =Γ0 / x0U0 Among them, Γ * is the dimensionless starting vortex circulation of the leapfrogging plasma vortex structure, U0 is the initial convection velocity between vortex pair one and vortex pair two, x0 is the initial convection distance between vortex pair one and vortex pair two, and Γ0 is the initial circulation intensity of vortex pair one or vortex pair two.

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