Composite plasma synthetic jet exciter for aircraft attitude regulation and control

Abstract

The invention discloses a composite plasma synthetic jet exciter for aircraft attitude regulation and control. The composite plasma synthetic jet exciter comprises an exciter body, a discharge cavity, a cathode needle electrode, an anode needle electrode, an insulating dielectric layer, an exposed electrode, a buried electrode and a jet hole. During working, an electric arc is formed between the needle electrodes on the two sides of the discharge cavity, and gas in the discharge cavity is instantly heated and flows to the jet hole; meanwhile, gas discharges on the surface of a plate-shaped electrode at the top of the exciter, generated ions are induced by an electric field to conduct secondary acceleration on gas flow, and high-speed jet flow is sprayed outwards from a jet flow outlet. The structure and characteristics of a traditional plasma synthetic jet exciter are not damaged, the composite plasma synthetic jet exciter is formed, the performance of the traditional exciter is effectively improved, and the generated torque can effectively meet the requirement for attitude regulation and control of an aircraft.

Description

Technical Field

[0001] The present invention relates to an active flow control device, in particular to a plasma synthetic jet actuator. Background Art

[0002] Active flow control technology is one of the current research hotspots in the aerospace field. The development of active flow control technology is very important for improving the aerodynamic characteristics of hypersonic aircraft.

[0003] As a new type of active flow control device, a plasma synthetic jet actuator typically consists of an insulating cavity with holes / slits and multiple electrodes. Its complete operating cycle begins with a pulsed arc discharge between the electrodes. The large amount of heat generated by the ionized air rapidly increases the pressure within the cavity, causing a high-speed jet to be ejected outward from the jet hole. During the pulse interval, external air is re-inhaled into the cavity and mixed with the residual high-temperature gas to prepare for the next pulse. Plasma synthetic jet actuators not only retain the characteristics of traditional synthetic jet devices with no moving parts and zero net mass flow, but also have the advantages of simple structure, small size, and fast response time. They can generate high-frequency, high-speed pulsed jets in a very short time and are gradually being applied in hypersonic flow control.

[0004] Currently, plasma synthetic jet actuators have shown good application prospects in the fields of shock wave control, flow separation suppression and drag reduction. However, in terms of aircraft attitude control, traditional plasma synthetic jet actuators are limited by cavity size and discharge voltage, and the jets generated cannot meet the requirements of aircraft attitude control. There is an urgent need to explore methods to improve their performance. Summary of the Invention

[0005] Purpose of the invention: In view of the above-mentioned existing technologies, a composite plasma synthetic jet actuator for aircraft attitude control is proposed, which can provide large torque for aircraft attitude control and has a strong flow control effect.

[0006] Technical solution: A composite plasma synthetic jet actuator for aircraft attitude control, comprising an actuator body and an electrode structure; the actuator body comprises a cavity and a jet hole connected to the cavity; an insulating dielectric layer is provided on the wall of the jet hole; the electrode structure comprises a first electrode group embedded in the cavity, and a second electrode group located at the jet hole; the second electrode group consists of a bare electrode and a buried electrode, the bare electrode is half-buried in the surface of the insulating dielectric layer, the buried electrode is wrapped in the insulating dielectric layer, and the bare electrode and the buried electrode are separated by the insulating dielectric layer; the first electrode group is externally connected to a DC pulse power supply, the second electrode group is externally connected to a DC or AC pulse power supply, and the discharge frequency of the second electrode group is controlled to be staggered with the suction phase of the actuator.

[0007] Furthermore, the first electrode group is composed of a cathode needle electrode and an anode needle electrode, and the discharge ends of the cathode needle electrode and the anode needle electrode are respectively inserted into the cavity relative to each other; wherein, the distance between the discharge ends of the cathode needle electrode and the anode needle electrode is not greater than 4 mm, the diameter of the jet hole is not less than 2 mm, and the length of the jet hole is not less than 10 mm.

[0008] Furthermore, the sheet-shaped exposed electrode and buried electrode are arranged parallel to the axis of the jet hole, and are staggered and non-overlapping; wherein, the thickness of the exposed electrode and the buried electrode is between 10μm and 300μm, and the spacing between the exposed electrode and the buried electrode in the radial direction of the jet hole is not greater than 5mm.

[0009] Furthermore, the thickness of the insulating dielectric layer is less than 2 mm, and the relative dielectric constant of the insulating dielectric layer is 8-10.

[0010] Furthermore, the supply voltage and frequency of the DC pulse power supply connected to the first electrode group are adjustable, the maximum supply voltage is not less than 5kV, the pulse width is not less than 100ns, and the maximum modulation frequency is not less than 500Hz; the supply voltage and frequency of the pulse power supply connected to the second electrode group are continuously adjustable, and the maximum supply voltage of the pulse power supply is not less than 3kV, and the maximum modulation frequency is not less than 500Hz.

[0011] Beneficial effects: 1. Compared with traditional plasma synthetic jet actuators, the present invention proposes a composite plasma synthetic jet actuator, which effectively improves the performance of traditional actuators. The torque generated can meet the attitude control of the aircraft, especially for the large torque requirements during aircraft attitude control. It has good application prospects and the jet speed can be adjusted according to actual application needs.

[0012] 2. The invention does not destroy the structure and characteristics of the traditional plasma synthetic jet actuator, and retains all the advantages of the traditional plasma synthetic jet actuator, such as small size, light weight, simple structure, rapid response, and no complex gas supply device. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is a schematic diagram of the internal structure of the composite plasma synthetic jet actuator of the present invention; Figure 2 It is a schematic diagram of the structural arrangement of the composite plasma synthetic jet actuator of the present invention for realizing aircraft attitude control. DETAILED DESCRIPTION

[0014] The present invention will be further explained below with reference to the accompanying drawings.

[0015] like Figure 1 As shown, a composite plasma synthetic jet actuator for aircraft attitude control includes an actuator body 1, a cathode needle electrode 3, an anode needle electrode 4, an insulating dielectric layer 5, a bare electrode 6, and a buried electrode 7.

[0016] The material of the actuator body 1 is generally selected from materials with good insulation properties and certain strength, such as ceramics, polytetrafluoroethylene, etc., and is composed of a cavity 2 and a jet hole 8 that connects the cavity 2 with the external environment.

[0017] The cavity 2 of the actuator body 1 is provided with a through-hole extending through both sidewalls. The cathode needle electrode 3 is inserted and fixed at one end of the through-hole, and the anode needle electrode 4 is inserted and fixed at the other end, so that the discharge ends of the two electrodes are positioned opposite each other. The jet hole 8 is a cylindrical through-hole and is perpendicular to the cathode needle electrode 3 and the anode needle electrode 4.

[0018] The insulating dielectric layer 5 is fixed on the inner side of the hole wall of the jet hole 8; the sheet-shaped exposed electrode 6 is half buried in the insulating dielectric layer 5, and the buried electrode 7 is wrapped in the insulating dielectric layer 5. The exposed electrode 6 and the buried electrode 7 are separated by the insulating dielectric layer 5.

[0019] In some embodiments, the diameter of the jet hole 8 is not less than 2 mm and the length is not less than 10 mm; the distance between the cathode needle electrode 3 and the anode needle electrode 4 is not greater than 4 mm. The cathode needle electrode 3 and the anode needle electrode 4 are externally connected to a DC pulse power supply, and the pulse power supply voltage is continuously adjustable, the pulse width is adjustable, and the frequency is adjustable. The maximum supply voltage of the pulse power supply is not less than 5 kV, and the pulse width is not less than 100 ns. The jet performance is controlled by changing the voltage amplitude and pulse width. The maximum modulation frequency is not less than 500 Hz. The discharge frequency is appropriately increased according to the actual working conditions to improve the continuous working performance of the exciter. At the same time, it must be ensured that the discharge frequency is less than the current saturation heating frequency.

[0020] In some embodiments, the sheet-like exposed electrode 6 and the buried electrode 7 are arranged parallel to the axis of the jet hole 8. The number of sheet-like exposed electrodes 6 and buried electrodes 7 can be determined according to the size of the electrode and the jet hole 8, and each exposed electrode 6 and buried electrode 7 is staggered and does not overlap in the axial direction of the jet hole 8. The thickness of the insulating dielectric layer 5 is less than 2 mm, and the relative dielectric constant is 10; the spacing between the exposed electrode 6 and the buried electrode 7 in the radial direction of the jet hole is not greater than 5 mm; the thickness of the exposed electrode 6 and the buried electrode 7 is between 10 μm and 300 μm. The exposed electrode 6 and the buried electrode 7 are externally connected to a DC or AC pulse power supply, and the pulse power supply voltage and frequency are continuously adjustable. The maximum supply voltage of the pulse power supply is not less than 3 kV, and the maximum modulation frequency is not less than 500 Hz. By controlling the discharge frequency of this group of electrodes, the discharge and the suction phase of the exciter are staggered to ensure the overall suction efficiency of the exciter.

[0021] During operation, an arc forms between the needle electrodes on either side of cavity 2, instantly heating the gas within the cavity and causing it to flow toward jet orifice 8. Simultaneously, the gas discharges on the plate-shaped electrode surface within jet orifice 8, generating ions that, under the influence of the electric field, secondary accelerate the gas flow, ejecting a high-speed jet from the jet outlet. In other words, the dielectric barrier discharge formed between exposed electrode 6 and buried electrode 7 secondary accelerates the jet formed by the arc discharge between cathode needle electrode 3 and anode needle electrode 4, resulting in a greater torque generated by the jet ejection, which is of great significance for achieving aircraft attitude control.

[0022] like Figure 2 Figure 2 shows the arrangement of a composite plasma synthetic jet actuator for aircraft attitude control on aircraft 9 according to the present invention. Several composite plasma synthetic jet actuators are arranged inside aircraft 9, one side of the aircraft's center of mass, with 5 mm spacing between each unit. The axes of the jet outlets 8 are perpendicular to the surface of aircraft 9. The reverse force generated by the jet ejection can exert a deflection torque on the aircraft. The arrangement of the array of actuators along the aircraft's center of mass ensures consistency in the direction of the torque, thereby achieving aircraft attitude control.

[0023] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A composite plasma synthetic jet actuator for aircraft attitude control, characterized in that: including an actuator body and an electrode structure; The actuator body includes a cavity and a jet hole connected to the cavity; an insulating medium layer is provided on the hole wall of the jet hole; The electrode structure includes a first electrode group embedded in the cavity, and a second electrode group located at the jet hole; The second electrode group consists of a bare electrode and a buried electrode, wherein the bare electrode is half-buried in the surface of the insulating dielectric layer, the buried electrode is wrapped in the insulating dielectric layer, and the bare electrode and the buried electrode are separated by the insulating dielectric layer; The first electrode group is externally connected to a DC pulse power supply, and the second electrode group is externally connected to a DC or AC pulse power supply, and the discharge frequency of the second electrode group is controlled to be staggered with the suction phase of the exciter.

2. The composite plasma synthetic jet actuator according to claim 1, characterized in that: The first electrode group is composed of a cathode needle electrode and an anode needle electrode, and the discharge ends of the cathode needle electrode and the anode needle electrode are respectively inserted into the cavity relative to each other; wherein, the distance between the discharge ends of the cathode needle electrode and the anode needle electrode is not greater than 4 mm, the diameter of the jet hole is not less than 2 mm, and the length of the jet hole is not less than 10 mm.

3. The composite plasma synthetic jet actuator according to claim 1 or 2, characterized in that: The sheet-shaped exposed electrode and buried electrode are arranged parallel to the axis of the jet hole, and are staggered and non-overlapping; wherein, the thickness of the exposed electrode and the buried electrode is between 10μm and 300μm, and the spacing between the exposed electrode and the buried electrode in the radial direction of the jet hole is not greater than 5mm.

4. The composite plasma synthetic jet actuator according to claim 3, characterized in that: The thickness of the insulating medium layer is less than 2 mm, and the relative dielectric constant of the insulating medium layer is 8-10.

5. The composite plasma synthetic jet actuator according to claim 4, characterized in that: The supply voltage and frequency of the DC pulse power supply connected to the first electrode group are adjustable, the maximum supply voltage is not less than 5kV, the pulse width is not less than 100ns, and the maximum modulation frequency is not less than 500Hz; the supply voltage and frequency of the pulse power supply connected to the second electrode group are continuously adjustable, and the maximum supply voltage of the pulse power supply is not less than 3kV, and the maximum modulation frequency is not less than 500Hz.

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