Control surface synergistic wing structure and method based on plasma excitation

Abstract

The invention relates to the technical field of aircraft design and plasma flow control, and particularly provides a control surface synergistic wing structure and method based on plasma excitation, the wing structure comprises a wing, a control surface and a dielectric barrier discharge plasma exciter, the control surface is rotatably connected to the tail end of the wing, and the dielectric barrier discharge plasma exciter is connected to the tail end of the wing. The dielectric barrier discharge plasma exciter comprises an upper exposed electrode, a lower exposed electrode, a buried electrode and an insulating dielectric layer, the upper exposed electrode and the lower exposed electrode are arranged at the ends, close to the control surface, of the upper surface and the lower surface of the wing respectively, and the buried electrode is attached to the cambered surface protruding end of the control surface. An insulating medium layer is arranged on one surface, close to the wing, of the buried electrode, and a discharge gap is formed between the insulating medium layer and the cambered surface concave end of the wing. Flow control over the aircraft wing control surface can be achieved, and then the maneuvering maneuverability and flight reliability of an aircraft are improved.

Description

Technical Field

[0001] This invention relates to the fields of aircraft design and plasma flow control technology, and in particular provides a control surface enhancement wing junction and method based on plasma excitation, which relates to plasma dielectric barrier discharge flow control technology, and adopts a novel electrode arrangement to achieve stable control surface enhancement under different flight conditions. Background Technology

[0002] Currently, the struggle for air superiority has become one of the decisive factors in modern warfare. As the backbone of a nation's aerospace power, the maneuverability, reliability, and survivability of next-generation fighter jets are directly related to national security and strategic deterrence. Currently, the key bottleneck restricting the performance improvement of my country's next-generation fighter jets is the problem of reduced control effectiveness of traditional control surfaces under extreme flight conditions. Under extreme maneuvering conditions such as high speed and high angle of attack, the control surfaces of fighter jets are prone to flow separation, leading to a sharp drop in control effectiveness, control delay, or even failure. This not only severely limits the agility and air combat capabilities of the fighter jet but also poses a direct threat to the safety of pilots and equipment. Therefore, suppressing flow separation and improving control surface effectiveness is an important task in the current aviation field.

[0003] In control surface enhancement research, the core methods can be summarized into three main categories: geometric shape modification, system integrated control, and flow energy injection. While geometric shape modification is widely used due to its simple structure and high reliability, its fixed performance and inability to adapt to varying flight conditions limit further breakthroughs in aircraft aerodynamic performance. It may also generate additional structural loads, affecting the aircraft's structural safety and stability. System integrated control optimizes the allocation and coordinated operation of each control surface, improving the efficiency of each surface. However, multi-control surface coordinated control technology faces significant technical barriers due to highly complex flight control software, sophisticated sensor networks, and strong aerodynamic coupling that is difficult to model accurately. In contrast, energy injection can actively and controllably alter the local flow field of the control surface, providing efficient and rapid aerodynamic control capabilities, especially under extreme flight conditions such as high angles of attack where traditional control surface efficiency drops sharply. Among these, plasma excitation demonstrates significant advantages in control surface enhancement technology due to its relatively simple structure, microsecond-level rapid response, and precise energy delivery capabilities. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention proposes a plasma-excited flow control technology for a wing structure and method that enhances control surfaces. This technology enables rapid, efficient, and stable flow control of aircraft wing control surfaces, thereby improving the aircraft's maneuverability and flight reliability.

[0005] This invention is implemented as follows: a plasma-excited control surface enhancement wing structure is provided, including a wing, control surfaces, and a dielectric barrier discharge (DBD) plasma actuator. The arc-shaped protruding end of the control surface is rotatably connected to the arc-shaped concave end of the wing, with a certain rotational clearance between the control surface and the wing. The DBD plasma actuator includes an upper exposed electrode, a lower exposed electrode, a buried electrode, and an insulating dielectric layer. The upper and lower exposed electrodes are respectively disposed on the upper and lower surfaces of the wing near the control surface. The buried electrode is disposed in conjunction with the arc-shaped protruding end of the control surface, extending from the upper surface to the lower surface of the control surface. An insulating dielectric layer is disposed on the side of the buried electrode near the wing, and the insulating dielectric layer forms a discharge gap with the arc-shaped concave end of the wing. The upper exposed electrode, the buried electrode, and the insulating dielectric layer constitute the upper actuator, and the lower exposed electrode, the buried electrode, and the insulating dielectric layer constitute the lower actuator.

[0006] Preferably, the upper exposed electrode, the lower exposed electrode, the insulating dielectric layer, and the buried electrode are distributed in a consistent manner along the wingspan.

[0007] Preferably, the end of the insulating dielectric layer located on the upper surface of the rudder surface is longer than the end of the buried electrode located on the upper surface of the rudder surface; the end of the insulating dielectric layer located on the lower surface of the rudder surface is longer than the end of the buried electrode located on the lower surface of the rudder surface.

[0008] Preferably, the thickness of the insulating dielectric layer is 0.2-0.5 mm, and the spacing of the discharge gaps is 0.5-5 mm.

[0009] Preferably, the buried electrode is connected to the rudder surface by surface application or internal embedding, and the insulating dielectric layer is connected to the buried electrode by adhesive bonding or embedding.

[0010] A plasma-excited control surface enhancement method is provided. Based on the aforementioned plasma-excited control surface enhancement wing structure, the method includes: When the control surface deflects downwards, the upper exciter is activated as needed, applying high-voltage, high-frequency alternating current between the upper exposed electrode and the buried electrode to form an upper plasma region. Under the action of the electric field, the plasma moves along the upper surface of the control surface, generating a stable, directional volume force in the fluid layer near the upper surface of the control surface, pointing in the direction of the control surface deflection. This volume force directly injects energy and momentum into the fluid layer near the upper surface of the control surface, enhancing the fluid layer's resistance to adverse pressure gradients, thereby suppressing or completely eliminating the flow separation vortex at the tail of the control surface, improving the airfoil circulation distribution, and making the lift of the control surface increase and the drag decrease at the same deflection angle, thus achieving control surface efficiency enhancement. When the control surface rotates at different angles, the voltage and frequency are adjusted to achieve optimal matching between the excitation parameters and flight conditions. When the control surface deflects upward, the lower exciter is activated as needed, applying high-voltage, high-frequency alternating current between the lower exposed electrode and the buried electrode to form a lower plasma region. Under the action of the electric field, the plasma moves along the lower surface of the control surface, generating a stable, directional volume force in the fluid layer near the lower surface of the control surface, pointing in the direction of the control surface deflection. This volume force directly injects energy and momentum into the fluid layer near the lower surface of the control surface, enhancing the fluid layer's resistance to adverse pressure gradients, thereby suppressing or completely eliminating flow separation vortices at the tail of the control surface, improving the airfoil circulation distribution, and increasing the lift and reducing the drag of the control surface at the same deflection angle, thus achieving control surface efficiency enhancement. When the control surface rotates at different angles, the voltage and frequency are adjusted to achieve optimal matching between excitation parameters and flight conditions.

[0011] Compared with the prior art, the advantages of the present invention are as follows: 1. The separate electrode arrangement ensures that the discharge gap of the plasma actuator remains consistent during the discharge process, making the plasma actuator discharge more uniform and thus achieving more stable control surface enhancement. 2. It has high adjustability. Compared with the control surface enhancement method of changing the geometric shape, the present invention can actively adjust the excitation parameters according to different flight conditions, thereby achieving control surface enhancement under different conditions. 3. The plasma exciter is started and stopped electronically, with a response speed of up to milliseconds. It can realize real-time active control of the flow field with ultra-high frequency and high precision, which significantly improves the aircraft's instantaneous adaptability to complex flow conditions. 4. The plasma is generated at the gaps in the control surface, which can reduce the intensity of the secondary scattering source in the control surface gap, thereby improving the stealth performance of the aircraft. Attached Figure Description

[0012] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments: Figure 1 This is a schematic diagram showing the arrangement of the DBD on the overall wing; Figure 2 This diagram shows the distribution structure of the upper and lower actuators on the wing and control surfaces, as well as the generated plasma region. Figure 3 A schematic diagram of the overall airflow around the wing when the upper exciter is off (a) and a schematic diagram of the airflow at the control surface position (b). Figure 4 A schematic diagram of the overall airflow around the wing when the upper exciter is activated (a) and a schematic diagram of the airflow at the control surface position (b). Detailed Implementation

[0013] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the invention.

[0014] The technical solution adopted by this invention to solve the problem of low maneuverability of aircraft due to flow separation is as follows: Figure 1 As shown, dielectric barrier discharge plasma exciters are arranged on the wings and control surfaces of the aircraft to effectively suppress flow separation on the control surfaces during startup. When the flight control system commands the control surfaces to deflect, the plasma exciters are activated, applying high-voltage, high-frequency alternating current between the two electrodes to generate plasma. Under the influence of the electric field, the plasma moves in a directional manner, enhancing the kinetic energy of the fluid near the wall and improving its ability to resist adverse pressure gradients. This results in increased lift and decreased drag at the same deflection angle, achieving enhanced control surface efficiency.

[0015] During plasma actuator discharge, voltage and frequency are two key adjustable parameters affecting the discharge result. The voltage amplitude directly determines the intensity and range of the plasma, while the frequency determines the energy injection time. Therefore, voltage and frequency can be adjusted in real time during flight to achieve optimal matching between excitation parameters and flight conditions. This parameter adjustability enables the plasma flow control system to adapt to complex flight conditions, ensuring that the control surface enhancement effect is maximized and optimized throughout the entire operating range, thereby comprehensively improving the aircraft's control efficiency, stall margin, and maneuverability.

[0016] This invention uses a dielectric barrier discharge plasma actuator, which mainly consists of three parts: exposed electrodes, buried electrodes, and an insulating dielectric layer, such as... Figure 2As shown, the upper exposed electrode 3, the buried electrode 4, and the insulating dielectric layer 5 constitute the upper exciter, while the lower exposed electrode 7, the buried electrode 4, and the insulating dielectric layer 5 constitute the lower exciter. A sufficiently high AC voltage is applied between the exposed and buried electrodes using an AC power supply. The electric field strength near the exposed electrode exceeds the air breakdown threshold, causing ionization of the air in that region and forming numerous dispersed fine discharge filaments or uniform glow discharges. These discharge processes efficiently inject electrical energy into gas molecules, exciting and ionizing them, causing them to move rapidly under the influence of the electric field. Because the dielectric layer blocks the continuous conduction of current and causes the discharge to manifest as numerous transient micro-discharges, the overall discharge is stably maintained in a non-thermal equilibrium state. In the discharge region, momentum collisions between neutral gas molecules and charged particles generate a net volume force in the local gas, pointing from the high-voltage electrode to the grounding electrode. This force efficiently transfers momentum to the surrounding air, achieving directional acceleration or energy injection of the fluid within the boundary layer, thereby suppressing flow separation. When rudder surface 2 deflects downward, the upper exciter is activated; when rudder surface 2 deflects upward, the lower exciter is activated. The excitation intensity of the two exciters increases with the increase of the rudder deflection angle, thereby improving the rudder efficiency at all rudder deflection angles.

[0017] Taking the following operating conditions as an example: Assuming the control surface 2 deflects downwards by 15°, the incoming flow velocity is 5 m / s, and the angle of attack is 0°, a numerical simulation of the flow field distribution is performed. When the plasma actuator is off, the simulation results are as follows: Figure 3 As shown in (a), a clear flow separation phenomenon occurs at the location marked by the dot in the figure. The formation of this separation point is closely related to the local adverse pressure gradient caused by the deflection of the control surface, indicating that the boundary layer can no longer maintain its attachment state at this location. Further observation of the flow field structure reveals a significant vortex structure formed in the tail region of the control surface, as shown in Figure (a). Figure 3 As shown in (b), the vortex is formed by the swirling of the separated shear layer. Its generation and evolution will change the local pressure distribution around the airfoil, resulting in reduced rudder effectiveness. It may also cause aerodynamic noise and vibration, which will have a negative impact on the aerodynamic characteristics of the wing.

[0018] When the exciter is turned on, the simulation results are as follows: Figure 4 As shown in (a), with Figure 3 (a) Compared to the previous findings, the separation point at the control surface disappeared, and flow separation was successfully suppressed. This is because after the plasma actuator is activated, a directionally stable volume force is generated within the boundary layer of the control surface. This volume force injects momentum and energy into the low-energy airflow, thereby enhancing the control surface airflow's ability to resist adverse pressure gradients, ultimately suppressing flow separation and eliminating it. Figure 3 (b) The flow separation vortex improves the circulation distribution around the wing, achieving the ultimate goal of increasing lift and reducing drag.

[0019] In summary, this invention proposes a plasma-excited control surface enhancement wing structure and method. Building upon existing technologies, the design and layout of the plasma actuator are optimized. The unique electrode arrangement ensures that the discharge gap remains constant during control surface deflection, resulting in uniform and stable plasma actuator discharge. This effectively improves the control efficiency of the airflow around the wing, while simultaneously optimizing the overall aerodynamic performance of the wing, achieving increased lift and reduced drag. This provides a practical and feasible technical approach for achieving active, efficient, and rapid flow control and improving control surface efficiency.

[0020] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A wing structure with enhanced control surfaces based on plasma excitation, characterized in that, The device includes a wing (1), a control surface (2), and a dielectric barrier discharge plasma actuator. The convex end of the control surface (2) is rotatably connected to the concave end of the wing (1). There is a certain rotational clearance between the control surface (2) and the wing (1). The dielectric barrier discharge plasma actuator includes an upper exposed electrode (3), a lower exposed electrode (7), a buried electrode (4), and an insulating dielectric layer (5). The upper exposed electrode (3) and the lower exposed electrode (7) are respectively located on the upper and lower surfaces of the wing (1) near the control surface (2). At one end, the buried electrode (4) is attached to the arc-shaped protrusion of the control surface (2) and extends from the upper surface of the control surface (2) to the lower surface. An insulating dielectric layer (5) is provided on the side of the buried electrode (4) close to the wing (1). The insulating dielectric layer (5) and the arc-shaped concave end of the wing (1) form a discharge gap (6). The upper exposed electrode (3), the buried electrode (4) and the insulating dielectric layer (5) constitute the upper exciter, and the lower exposed electrode (7), the buried electrode (4) and the insulating dielectric layer (5) constitute the lower exciter.

2. The plasma-excited control surface-enhanced wing structure according to claim 1, characterized in that, The upper exposed electrode (3), the lower exposed electrode (7), the insulating dielectric layer (5), and the buried electrode (4) are distributed in a consistent manner along the wingspan.

3. The plasma-excited control surface-enhanced wing structure according to claim 1, characterized in that, The end of the insulating dielectric layer (5) located on the upper surface of the rudder surface (2) is longer than the end of the buried electrode (4) located on the upper surface of the rudder surface (2); the end of the insulating dielectric layer (5) located on the lower surface of the rudder surface (2) is longer than the end of the buried electrode (4) located on the lower surface of the rudder surface (2).

4. The plasma-excited control surface-enhanced wing structure according to claim 1, characterized in that, The thickness of the insulating dielectric layer (5) is 0.2-0.5 mm, and the spacing of the discharge gaps (6) is 0.5-5 mm.

5. The plasma-excited control surface-enhanced wing structure according to claim 1, characterized in that, The buried electrode (4) is connected to the rudder surface (2) by surface application or internal embedding, and the insulating dielectric layer (5) is connected to the buried electrode (4) by adhesive bonding or embedding.

6. A method for enhancing control surfaces based on plasma excitation, characterized in that, Based on the plasma-excited control surface enhanced wing structure according to any one of claims 1-5, the method includes: When the control surface (2) deflects downward, the upper exciter is activated as needed, and a high-voltage high-frequency alternating current is applied between the upper exposed electrode (3) and the buried electrode (4) to form an upper plasma region (8). The plasma moves along the upper surface of the control surface under the action of the electric field, and generates a stable and directional volume force in the fluid layer near the upper surface of the control surface (2) pointing in the direction of deflection of the control surface (2). This volume force directly injects energy and momentum into the fluid layer near the upper surface of the control surface (2), enhances the fluid layer's ability to resist adverse pressure gradient, thereby suppressing or completely eliminating the flow separation vortex at the tail of the control surface (2), improving the airfoil circulation distribution, so that under the same deflection angle, the lift of the control surface (2) increases and the drag decreases, thereby achieving control surface efficiency. When the angle of rotation of the control surface (2) is different, the voltage and frequency are adjusted to achieve the optimal matching of excitation parameters and flight conditions. When the control surface (2) deflects upward, the lower exciter is activated as needed, and a high-voltage high-frequency alternating current is applied between the lower exposed electrode (7) and the buried electrode (4) to form a lower plasma region (9). The plasma moves along the lower surface of the control surface under the action of the electric field, and generates a stable and directional volume force in the fluid layer near the lower surface of the control surface (2) pointing in the direction of deflection of the control surface (2). This volume force directly injects energy and momentum into the fluid layer near the lower surface of the control surface (2), enhances the fluid layer's ability to resist adverse pressure gradient, thereby suppressing or completely eliminating the flow separation vortex at the tail of the control surface (2), improving the airfoil circulation distribution, so that under the same deflection angle, the lift of the control surface (2) increases and the drag decreases, thereby achieving control surface efficiency enhancement. When the angle of rotation of the control surface (2) is different, the voltage and frequency are adjusted to achieve the optimal matching of excitation parameters and flight conditions.

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