Surface convection heat transfer enhanced plasma deicing device and method

Abstract

Disclose a surface convection heat transfer enhancement type plasma anti-icing device, including bare electrode (1), cover electrode (2), insulation layer (3), corona discharge cathode (4), corona discharge anode (5), wherein bare electrode (1) and cover electrode (2) are both wave-shaped electrode.Bare electrode (1) is connected with the high-voltage end of airborne pulse plasma power supply (6) by wire, cover electrode (2) is connected with the low-voltage end of airborne pulse plasma power supply (6) by wire.A surface convection heat transfer enhancement type plasma anti-icing method is also provided.The exciter can generate plasma at bare electrode (1) and the inclined through hole of corona discharge cathode (4), two plasma jets are coupled to form a normal vortex spirally rising, greatly improving the wall air flow rate, increasing the thickness of the plasma zone, and promoting convection heat transfer.The invention can adjust the discharge intensity and density in real time according to the working condition to meet the anti-icing needs under different working conditions, and has good engineering application prospect.

Description

Technical Field

[0001] This invention relates to devices and methods for anti-icing and de-icing of aircraft surfaces, specifically to a surface convection heat transfer enhanced plasma anti-icing device and method. Background Technology

[0002] When aircraft fly in icing weather conditions, supercooled water droplets in clouds impact the windward surfaces of aircraft components and rapidly freeze. Icing of critical aircraft components can severely impact handling, stability, and safety. For example, icing on the leading edges of wings and tail rotors disrupts aerodynamic shape, reducing lift and increasing drag, significantly affecting aerodynamic performance; icing on engine lips reduces engine efficiency and thrust, and in severe cases, can damage engine blades, causing them to stop operating; icing on windshields reduces visibility, creating safety hazards during flight; and icing on instrument sensors (such as speed sensors) can cause equipment malfunction or data distortion, misleading pilots and potentially leading to a crash. Therefore, de-icing measures must be implemented on vulnerable parts of the aircraft to improve its safety performance.

[0003] Currently, the main anti-icing methods include thermal de-icing systems, mechanical de-icing systems, and superhydrophobic material anti-icing systems. Thermal de-icing systems can be divided into electrothermal and pneumatic anti-icing systems based on the heat source. Electrothermal anti-icing systems are highly reliable and easy to implement, but their complex structure, large weight, slow heating rate, and low energy utilization rate are drawbacks. Pneumatic anti-icing technology is simple in principle and reliable in operation, but drawing air from the engine or auxiliary engine can affect engine performance, has significant thermal inertia, slow response, and low energy utilization. Superhydrophobic materials can reduce the adhesion between ice and the surface and delay droplet icing, but their manufacturing process is complex and costly. In low-temperature and high-humidity environments, they suffer from loss of hydrophobicity and poor durability, resulting in low reliability. Currently, plasma anti-icing technology is rapidly developing. As an active anti-icing technology, plasma anti-icing has advantages such as simple structure, fast response, wide bandwidth, and ease of automation. However, common dielectric barrier discharge plasma de-icing methods have high energy consumption and low efficiency, limiting their application. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a surface convection heat transfer enhanced plasma anti-icing device, comprising an exposed electrode 1, a covered electrode 2, an insulating layer 3, a corona discharge cathode 4, and a corona discharge anode 5, wherein...

[0005] A first insulating layer 31 is added to the corona discharge cathode 4 of the rectangular thin metal plate. The first insulating layer 31 has a thin rectangular structure and its projection on the horizontal plane coincides with the projection of the corona discharge cathode 4 on the horizontal plane.

[0006] Dielectric barrier discharge masking electrodes 2 are uniformly arranged on the upper surface of the first insulating layer 31 to serve as dielectric barrier discharge cathodes.

[0007] A second insulating layer 32 is added to the upper surface of the masking electrode 2. The second insulating layer 32 is exactly the same as the first insulating layer 31, and its projection on the horizontal plane coincides with the projection of the corona discharge cathode 4 on the horizontal plane.

[0008] A dielectric barrier discharge exposed electrode 1 is placed on the upper surface of the second insulating layer 32 at a position corresponding to the edge of the masking electrode 2 as the dielectric barrier discharge anode. The edges of the masking electrode 2 and the exposed electrode 1 coincide, and the projection of the exposed electrode 1 on the horizontal plane does not coincide with the projection of the masking electrode 2 on the horizontal plane.

[0009] Both the exposed electrode 1 and the masking electrode 2 are wavy electrodes. The exposed electrode 1 and the masking electrode 2 are arranged in the form 1²-N*2¹²-2¹, where N is a positive integer. "1" represents one exposed electrode 1, and "2" represents one masking electrode 2. Except for the special arrangement at both ends, the middle section consists of N groups of "1²¹" arrangements. The exposed electrode 1 and the masking electrode 2 are grouped at intervals. Except for the outermost two groups, each group consists of three electrodes of identical shape from left to right: the first masking electrode 2, the exposed electrode 1, and the second masking electrode 2. The electrodes are adjacent to each other on the left and right sides along their curvature. The right edge of the first masking electrode 2 coincides with the projection of the left edge of the exposed electrode 1 on the horizontal plane, and the right edge of the exposed electrode 1 coincides with the projection of the left edge of the second masking electrode 2 on the horizontal plane. The two outermost sets of electrodes are: the leftmost set from left to right includes the exposed electrode 1 and the masking electrode 2, with the right edge of the exposed electrode 1 and the left edge of the masking electrode 2 coinciding on the horizontal plane; the rightmost set from left to right includes the masking electrode 2 and the exposed electrode 1, with the right edge of the masking electrode 2 and the left edge of the exposed electrode 1 coinciding on the horizontal plane.

[0010] A pair of cylindrical oblique through holes are drilled at the midpoint between the closest points of the left and right adjacent cover electrodes 2, and at the midpoint between the two. The cylindrical oblique through holes penetrate the second insulating layer 32, the first insulating layer 31, and the corona discharge cathode 4; therefore, the corona discharge cathode 4 has cylindrical oblique through holes. This pair of cylindrical oblique through holes with close proximity and different inclination directions is a group. The center of the cylindrical oblique through holes is located on the perpendicular bisector of the line connecting the closest points of the two relatively exposed electrodes 1, and the center of the upper surface of the pair of cylindrical oblique through holes is symmetrical about the line connecting them. The inclination angle of each pair of cylindrical oblique through holes is symmetrical about the plane that passes through the perpendicular bisector and is perpendicular to the first insulating layer 31.

[0011] A cylindrical corona discharge anode 5 is fixedly arranged under each through hole of the corona discharge cathode 4, and there is a space between the corona discharge cathode 4 and the cylindrical corona discharge anode 5; the corona discharge cathode 4 is fixed on the surface of the fuselage area that needs to be de-iced and is flush with the surface; the corona discharge cathode 4 is connected by a lead wire buried inside the fuselage skin; the cylindrical corona discharge anode 5 is fixed inside the fuselage and is electrically insulated from other fuselage components except for the corona discharge cathode 4.

[0012] The surface convection heat transfer enhanced plasma anti-icing device comprises a six-layer structure from bottom to top, consisting of a corona discharge anode 5, a corona discharge cathode 4, a first insulating layer 31, a masking electrode 2, a second insulating layer 32, and an exposed electrode 1; the projections of the exposed electrode 1, the masking electrode 2, and the corona discharge cathode 4 on the horizontal plane do not exceed the edge of the projection of the insulating layer on the horizontal plane.

[0013] The exposed electrode 1 is the high-voltage electrode of the dielectric barrier discharge plasma exciter. The exposed electrode 1 is distributed in a grid pattern and has an overall wavy shape. The spacing of the grid is reasonably arranged according to the anti-icing area. The exposed electrode 1 includes multiple wavy electrodes arranged along the width direction on the second insulating layer 32. The protrusions of two adjacent exposed electrodes 1 are aligned with each other, and the recesses are aligned with each other. The spacing between the protrusions and recesses of two adjacent exposed electrodes 1 is equal. The length of the exposed electrode 1 is selected according to the requirements. The exposed electrode 1 is attached to the upper surface of the second insulating layer 32. The projection of the exposed electrode 1 on the horizontal plane does not exceed the edge of the projection of the insulating layer on the horizontal plane.

[0014] The masking electrode 2 is the low-voltage electrode of the dielectric barrier discharge plasma exciter. The masking electrode 2 is distributed in a grid pattern and is generally wavy. It is placed in the corresponding position to the exposed electrode 1. The wavy edges of the two overlap in the horizontal projection. The projection of the exposed electrode 1 on the horizontal plane does not overlap with the projection of the masking electrode 2 on the horizontal plane. The spacing of the grid is reasonably arranged according to the anti-icing area. The masking electrode 2 includes multiple wavy electrodes arranged along the width direction of the first insulating layer 31. The protrusions of two adjacent exposed electrodes 1 are aligned with each other, and the recesses are aligned with each other. The spacing between the protrusions of two adjacent masking electrodes 2 and the spacing between the recesses are equal. The masking electrode 2 is attached between the first insulating layer 31 and the second insulating layer 32. The projection of the masking electrode 2 on the horizontal plane does not exceed the edge of the projection of the insulating layer on the horizontal plane.

[0015] The corona discharge cathode 4 is a thin cuboid shape, with multiple cylindrical oblique through holes on its upper surface from top to bottom. Each pair of adjacent cylindrical oblique through holes forms a group. In the longitudinal direction, the odd-numbered rows of cylindrical oblique through holes have the same tilt direction and tilt angle, and their axes are parallel to each other and lie in the same horizontal vertical plane perpendicular to the front of the corona discharge cathode 4. The even-numbered rows of cylindrical oblique through holes have the same tilt angle, and the tilt direction of the odd-numbered rows of cylindrical oblique through holes is symmetrical to the tilt direction of the even-numbered rows about the longitudinal vertical plane perpendicular to the front of the corona discharge cathode 4.

[0016] The corona discharge anode 5 is coaxial with the lower surface circle of the cylindrical oblique through hole, and each corona discharge anode 5 corresponds to a cylindrical through hole on the corona discharge cavity plate.

[0017] In one embodiment of the present invention, the exposed electrode 1 has a width of 1mm-10mm and a thickness of 0.06mm-0.2mm; the covered electrode 2 has a width of 1mm-10mm and a thickness of 0.06mm-0.2mm.

[0018] In one specific embodiment of the present invention,

[0019] The closest distance between the protrusions of two adjacent bare electrodes 1 is 7mm; the material of the bare electrode 1 is copper foil, the width of the bare electrode 1 is 2mm, and the thickness is 0.08mm;

[0020] The closest distance between the protrusions of two adjacent masking electrodes 2 is 5mm; the material of the masking electrode 2 is copper foil, the width of the masking electrode 2 is 2mm, and the thickness is 0.08mm;

[0021] The corona discharge cathode 4 is made of copper, with a length and width of 50 mm and 45 mm respectively, and a thickness of 3 mm. The diameter of the cylindrical oblique through holes on the corona discharge cathode 4 is 3 mm. The distance between the centers of each group of corona discharge cylindrical oblique through holes on the upper surface of the corona discharge cathode 4 is 4 mm. In the length direction, the distance between the center of the first and last cylindrical oblique through holes and the edge of the corona discharge cathode 4 is 2.5 mm. In the width direction, the distance between the first and last cylindrical oblique through holes and the edge of the corona discharge cathode 4 is 8 mm.

[0022] The corona discharge anode 5 is a solid corona needle made of copper or tungsten; the corona discharge anode 5 is a cylinder with a diameter of 1 mm and a height of 2 mm; the upper and lower circular surfaces of the corona discharge anode 5 are parallel to the horizontal plane, and the corona discharge cathode 4 and the cylindrical corona discharge anode 5 are spaced 2 mm apart.

[0023] In another specific embodiment of the present invention, there are a total of 14 cylindrical through holes.

[0024] In another embodiment of the present invention, both the first insulating layer 31 and the second insulating layer 32 are made of high-temperature resistant composite material.

[0025] In another specific embodiment of the present invention, the first insulating layer 31 and the second insulating layer 32 are both formed by bonding three or more layers of polyimide tape.

[0026] In yet another embodiment of the invention, the device is electrically connected as follows:

[0027] The exposed electrode 1 is connected to the high-voltage end of the airborne pulsed plasma power supply 6 via a wire, and the covered electrode 2 is connected to the low-voltage end of the airborne pulsed plasma power supply 6 via a wire.

[0028] The positive terminal of the high-voltage DC power supply 7 is connected to the electrode of the corona discharge anode 5, and the negative terminal is connected to the corona discharge cathode 4.

[0029] In yet another embodiment of the invention,

[0030] The pulsed plasma power supply 6 adopts an airborne pulsed plasma power supply;

[0031] High-voltage DC power supply 7: Select a high-voltage DC power supply with a voltage >8kV;

[0032] The high-voltage DC power supply 7 is located inside the cabin and is connected to the corona discharge anode 5 by a lead wire from the inside of the wing skin; the corona discharge cathode 4 is grounded by a lead wire through a perforation at the bottom.

[0033] A surface convection heat transfer enhanced plasma anti-icing method is also provided, which is based on the above-mentioned surface convection heat transfer enhanced plasma anti-icing device, and the method is as follows:

[0034] The entire surface convection heat transfer enhanced plasma anti-icing device is embedded inside the surface that needs anti-icing and de-icing, with the upper surface of the device flush with the de-icing surface; the anti-icing and de-icing devices are flexibly arranged according to the areas of the aircraft surface that are difficult to ic.

[0035] When supercooled water droplets impact the wing, the onboard pulsed plasma power supply 6 and high-voltage DC power supply 7 are activated. Dielectric barrier discharge plasma is formed in the gap between adjacent electrode strips of the exposed electrode 1 and the covered electrode 2. At the corona discharge cathode 4, oblique jets are ejected from each set of oblique through-holes, coupling to form spiraling, rising normal vortices. The nanosecond pulsed dielectric barrier discharge plasma has the effect of instantaneously heating the air and the wall surface. The normal vortex jets generated by the corona discharge can penetrate to higher positions on the surface, significantly increasing the air velocity at the wall surface and promoting convective heat transfer. Simultaneously, the normal vortexes also draw plasma generated by the DBD from the wall surface towards... The upward lifting increases the thickness of the plasma zone, thereby increasing the heating time for supercooled water droplets in the incoming flow before they collide with the wall. The airflow generated by the corona discharge is also hot air with a certain temperature, which can further enhance the heating effect. The protruding parts of the wave-shaped DBD high-voltage electrodes placed opposite each other on both sides of the cylindrical oblique through-hole are aligned with the center of the normal vortex, generating a concentrated electric field at the vortex, making the discharge stronger and forming a local high-heat zone. The vortex then transmits the local high-heat zone outward, enhancing the anti-icing capability. These multiple effects ensure that supercooled water droplets do not freeze on the wing surface, achieving the purpose of anti-icing.

[0036] To further improve plasma de-icing efficiency, this invention introduces corona blowing into the DBD discharge. Corona discharge ionizes air, forming charged particles that move at high speed under the influence of an electric field, creating a normal ion wind. This wind promotes the propagation of heat from the DBD surface into the air, enhancing convective heat transfer and thus improving de-icing efficiency while reducing energy consumption. Since the mechanical efficiency of corona discharge is an order of magnitude higher than that of DBD, the convective heat transfer generated by corona discharge is even stronger. Furthermore, the oblique jets ejected from adjacent oblique through-holes of the corona discharge are coupled to form a spiraling, rising normal vortex, further enhancing the mixing of hot gas on the exciter surface with the low-temperature incoming flow, thereby further strengthening convective heat transfer.

[0037] Meanwhile, to further enhance the convective heat transfer and air heating effects generated by the corona discharge, the DBD electrode is designed in a wave shape, concentrating the DBD discharge at the corona blowing point, making the discharge at the vortex stronger, increasing the temperature at that point, and thus enhancing the heating effect in the space above the exciter. Furthermore, the airflow generated by the corona discharge itself has a certain temperature of hot air, which can also further enhance the heating effect. Based on the above design principles, this invention can effectively promote surface convective heat transfer, increase the spatial thickness of the heating zone above the exciter, and thus increase the heating time before the supercooled water droplets in the incoming flow impact the wall surface, enhancing the anti-icing capability.

[0038] Compared to the invention patent "Multilayer Array Micropore Discharge Plasma Generator and Generation Method" (Publication No.: CN113543442A), this patent lacks a unidirectional electric field and cannot generate a jet, thus failing to achieve the convective heat transfer promotion effect of this invention. This invention, however, utilizes corona discharge, resulting in high mechanical efficiency. Compared to traditional hot gas jet de-icing and electrothermal de-icing methods, this invention does not impair engine performance, has a simple structure, rapid response, and a wide operating frequency band. Compared to popular passive de-icing methods using superhydrophobic materials, this invention is an active method, offering greater convenience, effectiveness, and environmental adaptability. It can adjust the discharge intensity and density in real time according to operating conditions to meet the de-icing needs under different working conditions. Attached Figure Description

[0039] Figure 1 A schematic diagram of the overall structure of the surface convection heat transfer enhanced plasma anti-icing device is shown.

[0040] Figure 2 A side view of a surface convection heat transfer enhanced plasma de-icing device is shown.

[0041] Figure 3 A top view showing the masked electrode arrangement of a surface convection heat transfer enhanced plasma de-icing device;

[0042] Figure 4 A schematic diagram of the corona discharge cathode is shown;

[0043] Figure 5 A top view of a surface convection heat transfer enhanced plasma de-icing device is shown.

[0044] Figure 6 A schematic diagram of the corona discharge anode is shown;

[0045] Figure 7 A schematic diagram of the exposed electrode and the covered electrode for dielectric barrier discharge is shown;

[0046] Figure 8 A schematic diagram of the connection lines of the present invention is shown. Attached image description:

[0048] 1. Dielectric barrier discharge exposed electrode; 2. Dielectric barrier discharge covered electrode; 3. Insulating layer; 4. Corona discharge cathode; 5. Corona discharge anode; 6. Pulsed plasma power supply; 7. High voltage DC power supply; 8. Plasma. Detailed Implementation

[0049] This invention provides a surface convection heat transfer enhanced plasma anti-icing device, which specifically comprises:

[0050] A first insulating layer 31 is added to the corona discharge cathode 4 of the rectangular thin metal plate. The first insulating layer 31 has a thin rectangular structure, and its projection on the horizontal plane coincides with the projection of the corona discharge cathode 4 on the horizontal plane.

[0051] Dielectric barrier discharge (DPD) masking electrodes 2 are uniformly arranged on the upper surface of the first insulating layer 31 to serve as DPD cathodes, such as... Figure 1 , Figure 2 , Figure 3 As shown ( Figure 1 , Figure 2 This is a perspective view of the device. Figure 3 (Top view of the actual electrode arrangement to conceal the arrangement)

[0052] A second insulating layer 32 is added to the upper surface of the masking electrode 2. The second insulating layer 32 is exactly the same as the first insulating layer 31, and its projection on the horizontal plane coincides with the projection of the corona discharge cathode 4 on the horizontal plane.

[0053] A dielectric barrier discharge exposed electrode 1 (e.g., ...) is placed on the upper surface of the second insulating layer 32 at a position corresponding to the edge of the masking electrode 2. Figure 1 As shown, the edge of the masking electrode 2 coincides with that of the exposed electrode 1 (the projection of the exposed electrode 1 on the horizontal plane does not coincide with the projection of the masking electrode 2 on the horizontal plane), serving as the dielectric barrier discharge anode.

[0054] Both the exposed electrode 1 and the covered electrode 2 are corrugated electrodes, such as Figure 7 As shown. The arrangement of the masking electrodes 2 is as follows. Figure 3 As shown. The exposed electrode 1 and the masking electrode 2 are arranged in the form of 12-N*2^(12-21) (N is a positive integer), where "1" represents one exposed electrode 1 and "2" represents one masking electrode 2. Except for the special arrangement at both ends, the middle has N sets of "121" arrangements. Figure 1 As shown, the exposed electrode 1 and the masking electrode 2 are grouped at intervals. Except for the outermost two groups, each group consists of three electrodes of identical shape from left to right: the first masking electrode 2, the exposed electrode 1, and the second masking electrode 2. The three electrodes are adjacent to each other along their curvature. For example, the right edge of the first masking electrode 2 coincides with the projection of the left edge of the exposed electrode 1 on the horizontal plane, and the right edge of the exposed electrode 1 coincides with the projection of the left edge of the second masking electrode 2 on the horizontal plane. The outermost two groups of electrodes are: the leftmost group from left to right includes the exposed electrode 1 and the masking electrode 2, with the right edge of the exposed electrode 1 coinciding with the projection of the left edge of the masking electrode 2 on the horizontal plane; the rightmost group from left to right includes the masking electrode 2 and the exposed electrode 1, with the right edge of the masking electrode 2 coinciding with the projection of the left edge of the exposed electrode 1 on the horizontal plane. Dielectric barrier discharge generates plasma along the direction from the exposed electrode 1 to the masking electrode 2 at the intersection of the exposed electrode 1 and the masking electrode 2.

[0055] At the midpoint of the closest distance between the two adjacent cover electrodes 2 (where the electrodes protrude relatively), and at the midpoint between them, make a pair of cylindrical oblique through holes (e.g., Figure 1 , Figure 3 As shown), the cylindrical oblique through-hole penetrates the second insulating layer 32, the first insulating layer 31, and the corona discharge cathode 4. Therefore, the corona discharge cathode 4 has a cylindrical oblique through-hole, as shown. Figure 4 As shown. This pair of closely spaced cylindrical oblique through-holes with different inclination directions forms a group. The centers of the cylindrical oblique through-holes are located on the perpendicular bisector of the line connecting the closest points (protrusions) of the two relatively exposed electrodes 1. Furthermore, the centers of the upper surfaces of the pair of cylindrical oblique through-holes are symmetrical about this line, as shown. Figure 5 As shown (the protruding part is circled in the figure). The angle of inclination of each pair of cylindrical oblique through holes is symmetrical about the plane passing through the perpendicular bisector and perpendicular to the first insulating layer 31.

[0056] A cylindrical corona discharge anode 5 is fixedly arranged under each through hole of the corona discharge cathode 4, with a space distance of 2 mm between the corona discharge cathode 4 and the cylindrical corona discharge anode 5. Figure 6 As shown, plasma 8 is generated between the corona discharge cathode 4 and the corona discharge anode 5, as... Figure 2 As shown. The corona discharge cathode 4 is fixed to the surface of the fuselage in the area requiring de-icing and is flush with the surface. The corona discharge cathode 4 is connected by a lead wire embedded inside the fuselage skin. The cylindrical corona discharge anode 5 is fixed inside the fuselage and is electrically insulated from other fuselage components except for the corona discharge cathode 4.

[0057] Therefore, the surface convection heat transfer enhanced plasma anti-icing device comprises a six-layer structure from bottom to top: a corona discharge anode 5, a corona discharge cathode 4, a first insulating layer 31, a covered electrode 2, a second insulating layer 32, and an exposed electrode 1, as shown below. Figure 1 , Figure 2 As shown, the projections of the exposed electrode 1, the covered electrode 2, and the corona discharge cathode 4 onto the horizontal plane will not exceed the edge of the projection of the insulating layer onto the horizontal plane.

[0058] Exposed electrode 1 is the high-voltage electrode of the dielectric barrier discharge plasma actuator. Exposed electrode 1 is distributed in a grid pattern and has an overall wavy shape, such as... Figure 7 As shown, the spacing of the grid can be reasonably arranged according to the anti-icing and de-icing area. The exposed electrode 1 is included on the second insulating layer 32 along the width direction (width direction is...). Figure 3Multiple wavy electrodes are arranged longitudinally, with adjacent exposed electrodes 1 protruding at the same point and recessed at the same point. The closest distance between the protrusions of two adjacent exposed electrodes 1 is 7 mm, and the spacing between the protrusions and recesses of two adjacent exposed electrodes 1 is equal. In one embodiment of the invention, the exposed electrode 1 is made of copper foil (a metal or metal alloy with relatively high conductivity), with a width of 1 mm to 10 mm, preferably 2 mm; a thickness of 0.06 mm to 0.2 mm, preferably 0.08 mm; and a length that can be selected according to requirements, such as whether it needs to reach the edge of the insulating layer 3. The exposed electrode 1 is attached to the upper surface of the second insulating layer 32, and the projection of the exposed electrode 1 on the horizontal plane does not exceed the edge of the projection of the insulating layer on the horizontal plane.

[0059] Masking electrode 2 is the low-voltage electrode of the dielectric barrier discharge plasma actuator. Masking electrode 2 is arranged in a grid pattern and has an overall wavy shape, such as... Figure 7 As shown, the electrodes are placed at corresponding positions to the exposed electrode 1, and their wavy edges coincide on the horizontal projection. The projection of the exposed electrode 1 on the horizontal plane does not coincide with the projection of the covered electrode 2 on the horizontal plane. Figure 1 , Figure 2 As shown ( Figure 1 , Figure 2 (Perspective view of the device). The spacing of the grids can be reasonably arranged according to the anti-icing and de-icing area. The cover electrode 2 includes a section along the width direction on the first insulating layer 31 (width direction is...). Figure 3 Multiple wavy electrodes are arranged longitudinally; adjacent exposed electrodes 1 are aligned with each other at their protrusions and recesses at their recesses. The spacing between the protrusions and recesses of adjacent covered electrodes 2 is equal. The closest distance between the protrusions of two adjacent covered electrodes 2 is 5 mm. In one embodiment of the invention, the covered electrode 2 is made of copper foil (a metal or metal alloy with relatively high conductivity), and its width is 1 mm to 10 mm, preferably 2 mm; its thickness is 0.06 mm to 0.2 mm, preferably 0.08 mm. The covered electrode 2 is attached between the first insulating layer 31 and the second insulating layer 32, and the projection of the covered electrode 2 on the horizontal plane does not exceed the edge of the projection of the insulating layer on the horizontal plane.

[0060] Both the first insulating layer 31 and the second insulating layer 32 are multilayer polyimide tapes or other high-temperature resistant composite materials with equivalent dielectric constants. In one embodiment of the present invention, both the first insulating layer 31 and the second insulating layer 32 are formed by bonding three or more layers of polyimide tape.

[0061] The corona discharge cathode 4 is a thin rectangular parallelepiped shape, such as... Figure 4As shown, it is made of conductive metals such as copper, silver, and tungsten. As described above, the upper surface of the corona discharge cathode 4 has multiple cylindrical oblique through holes from top to bottom. Each pair of adjacent cylindrical oblique through holes forms a group, such as... Figure 1 As shown, viewed longitudinally, there are ten rows from top to bottom. The odd-numbered rows of cylindrical oblique micro-orifices have the same tilt direction and angle, and their axes are parallel to each other and lie in the same horizontal vertical plane perpendicular to the front of the corona discharge cathode 4. The even-numbered rows of cylindrical oblique micro-orifices have the same tilt angle, and the tilt direction of the odd-numbered rows is symmetrical to that of the even-numbered rows about the longitudinal vertical plane perpendicular to the front of the corona discharge cathode 4. The corona discharge cathode 4 is connected to a high-voltage DC power supply 7, which is located inside the cabin and connected to the corona discharge cathode 4 via a lead wire from the inside of the wing skin. The corona discharge cathode 5 is grounded via a perforated lead wire at the bottom. The connections of all other corona discharge anodes 5 are made using techniques conventional in the art and will not be described further.

[0062] In one specific embodiment of the present invention, the corona discharge cathode 4 is made of copper, with a length and width of 50mm and 45mm respectively, and a thickness of 3mm. The diameter of the cylindrical oblique through-holes on the corona discharge cathode 4 is 3mm; the distance between the centers of each group of corona discharge cylindrical oblique through-holes on the upper surface of the corona discharge cathode 4 is (distance is...). Figure 5 The transverse direction is 4mm; in a specific embodiment of the present invention, there are a total of 14 cylindrical through holes, and the length direction (the length direction is...) is... Figure 5 (in the transverse direction), the distance between the center of the first and last cylindrical oblique through-holes and the edge of the corona discharge cathode 4 is 2.5 mm; in the width direction (width direction is...) Figure 5 (in the longitudinal direction), the distance between the first and last cylindrical oblique through holes and the edge of the corona discharge cathode 4 is 8mm.

[0063] The corona discharge anode 5 is a solid corona needle, such as... Figure 6 As shown, the corona discharge anode 5 is coaxial with the lower surface circle of the cylindrical oblique through-hole. After energization, the corona discharge cathode 4 and the corona discharge anode 5 generate plasma 8. The corona discharge anode 5 is typically made of copper or tungsten. In a specific embodiment of the present invention, the corona discharge anode 5 is made of copper and is a cylinder with a diameter of 1 mm and a height of 2 mm. Each corona discharge anode 5 corresponds to a cylindrical through-hole on the corona discharge cavity plate, which is parallel to the horizontal plane and 2 mm away.

[0064] The pulsed plasma power supply 6 is an airborne pulsed plasma power supply; the exposed electrode 1 is connected to the high-voltage end of the airborne pulsed plasma power supply 6 via a wire, and the covered electrode 2 is connected to the low-voltage end of the airborne pulsed plasma power supply 6 via a wire. The size and weight of the pulsed plasma power supply should be as small as possible to reduce the structural weight of the device and adapt to application scenarios with limited space and payload, such as UAVs.

[0065] The high-voltage DC power supply 7 is used to generate a high-voltage DC power supply to drive the corona discharge of the electrodes. Its positive terminal is connected to the electrode of the corona discharge anode 5, and its negative terminal is connected to the corona discharge cathode 4. When the high-voltage DC power supply 7 is turned on, corona plasma 8 will be generated between the electrodes. The high-voltage DC power supply 7 can be any high-voltage DC power supply with a voltage >8kV. The size and weight of the high-voltage DC power supply 7 should be as small as possible to reduce the structural weight of the device and adapt to application scenarios with limited space and load capacity, such as UAVs.

[0066] The surface convection heat transfer enhanced plasma anti-icing device and method of the present invention uses copper foil (a metal or metal alloy with relatively high conductivity) as exposed and covered electrodes, and multilayer polyimide or a high-temperature resistant composite material with equivalent dielectric constant as the insulating layer. The exposed electrodes are connected to the high-voltage end of the airborne pulsed plasma power supply via wires, and the covered electrodes are connected to the low-voltage end of the airborne pulsed plasma power supply via wires. Copper (a metal or metal alloy with relatively high conductivity) is used as the corona discharge anode and cathode. The corona discharge anode is connected to the high-voltage end of the airborne high-voltage DC power supply via wires, and the corona discharge cathode is connected to the low-voltage end of the airborne high-voltage DC power supply via wires. The entire surface convection heat transfer enhanced plasma anti-icing device is embedded inside the surface requiring anti-icing and de-icing, with the upper surface of the device flush with the de-icing surface. The anti-icing and de-icing device can be flexibly arranged according to the areas of difficulty in icing on the aircraft surface, ensuring rapid response and scientific and rational energy utilization.

[0067] Based on the above-mentioned device, the present invention also proposes a surface convection heat transfer enhanced plasma anti-icing and de-icing method, as follows:

[0068] When supercooled water droplets impact the wing, the onboard pulsed plasma power supply 6 and high-voltage DC power supply 7 are activated. Dielectric barrier discharge plasma is formed in the gap between adjacent electrode strips of the exposed electrode 1 and the covered electrode 2. At the corona discharge cathode 4, oblique jets from each set of oblique through-holes couple to form a spiraling, rising normal vortex. The nanosecond pulsed dielectric barrier discharge plasma instantaneously heats the air and the wall surface. The normal vortex jets generated by the corona discharge can penetrate deeper into the surface, significantly increasing the air velocity at the wall surface and promoting convective heat transfer. Simultaneously, the normal vortexes also lift the plasma generated by the DBD from the wall surface, increasing the thickness of the plasma zone and thus increasing the heating time before the supercooled water droplets in the incoming flow impact the wall surface. Furthermore, the airflow generated by the corona discharge itself is also hot air with a certain temperature, further enhancing the heating effect. Moreover, the protruding parts of the wavy DBD high-voltage electrodes, placed opposite each other on both sides of the cylindrical oblique through-holes, are aligned with the center of the aforementioned normal vortex, generating a concentrated electric field at the vortex, making the discharge stronger and forming a localized high-heat zone. Then, the vortex transfers the localized high-heat zone outwards, enhancing the anti-icing capability. These multiple mechanisms ensure that supercooled water droplets do not freeze on the wing surface, achieving the purpose of anti-icing.

[0069] The differences between this invention and other technologies in the same field are as follows:

[0070] Currently popular aircraft de-icing technologies mainly include electrothermal de-icing, gas thermal de-icing, and passive de-icing methods based solely on hydrophobic materials. In the use of plasma discharge for aircraft de-icing, the discharge method used is mostly dielectric barrier discharge, and there is no technology that uses corona discharge for aircraft de-icing.

[0071] Compared with other de-icing methods, the present invention has the following advantages:

[0072] 1. Enhanced adaptability. Compared to popular hydrophobic material-based de-icing methods, the surface convection heat transfer enhanced plasma de-icing device and method proposed in this invention are active methods. They can adjust the discharge intensity and density in real time according to changes in icing intensity during actual flight to meet the needs of aircraft de-icing. They can effectively adapt to rapidly changing weather conditions during actual flight, maintaining the aircraft in optimal flight condition at all times. The adaptability and practicality have been significantly enhanced, making them suitable for de-icing under extreme weather conditions.

[0073] 2. Simple structure and lightweight. Compared with hot gas de-icing methods, it does not require bleed air from the engine, resulting in a shorter air path and no damage to engine performance. Compared with electrothermal de-icing methods, the surface convection heat transfer enhanced plasma de-icing device and method proposed in this invention employs a simpler, lighter, easier-to-maintain, and more convenient exciter structure, which reduces aircraft weight and improves aircraft performance. It has broader application scenarios in space- and weight-constrained aircraft such as UAVs.

[0074] 3. Rapid Response. Since the electrodes of this invention can be controlled by a power supply signal, compared with traditional methods such as gas-thermal de-icing and hydrophobic materials, the exciter of this invention's surface convection heat transfer enhanced plasma de-icing has advantages such as simple structure, high frequency response, and fast response speed. This rapid response capability allows this invention to reach its optimal design state more quickly, achieving better de-icing effects.

Claims

1. A surface convection heat transfer enhanced plasma anti-icing device, characterized in that, The surface convection heat transfer enhanced plasma anti-icing device comprises, from bottom to top, a six-layer structure consisting of a corona discharge anode (5), a corona discharge cathode (4), a first insulating layer (31), a masking electrode (2), a second insulating layer (32), and an exposed electrode (1); the projections of the exposed electrode (1), the masking electrode (2), and the corona discharge cathode (4) onto the horizontal plane do not exceed the edge of the projection of the insulating layer onto the horizontal plane; wherein, A first insulating layer (31) is added to the corona discharge cathode (4) of the rectangular thin metal plate. The first insulating layer (31) is a thin rectangular structure, and its projection on the horizontal plane coincides with the projection of the corona discharge cathode (4) on the horizontal plane. Dielectric barrier discharge masking electrodes (2) are uniformly arranged on the upper surface of the first insulating layer (31) to serve as dielectric barrier discharge cathodes; A second insulating layer (32) is added to the upper surface of the masking electrode (2). The second insulating layer (32) is exactly the same as the first insulating layer (31), and its projection on the horizontal plane coincides with the projection of the corona discharge cathode (4) on the horizontal plane. A dielectric barrier discharge exposed electrode (1) is placed on the upper surface of the second insulating layer (32) at a position corresponding to the edge of the masking electrode (2) as the dielectric barrier discharge anode. The edges of the masking electrode (2) and the exposed electrode (1) coincide, and the projection of the exposed electrode (1) on the horizontal plane does not coincide with the projection of the masking electrode (2) on the horizontal plane. Both the exposed electrode (1) and the covered electrode (2) are wavy electrodes; the exposed electrode (1) and the covered electrode (2) are arranged in the form of 12-N*212-21, where N is a positive integer, and "1" represents one exposed electrode (1), "2" represents one covered electrode (2), and "3" represents one covered electrode (2). Representing a masking electrode (2), except for the special arrangement at both ends, the middle is N groups of "121 arrangement"; the exposed electrode (1) and the masking electrode (2) are grouped at intervals. Except for the two outermost groups, each group of electrodes consists of three electrodes with the same shape from left to right: the first masking electrode (2), the exposed electrode (1), and the second masking electrode (2). The three electrodes are adjacent to each other on the left and right edges along their curvature. The right edge of the first masking electrode (2) and the left edge of the exposed electrode (1) are projected onto the horizontal plane, and the right edge of the exposed electrode (1) and the left edge of the second masking electrode (2) are projected onto the horizontal plane. The two outermost groups of electrodes are: the leftmost group from left to right includes the exposed electrode (1) and the masking electrode (2), and the right edge of the exposed electrode (1) and the left edge of the masking electrode (2) are projected onto the horizontal plane. The rightmost group from left to right includes the masking electrode (2) and the exposed electrode (1), and the right edge of the masking electrode (2) and the left edge of the exposed electrode (1) are projected onto the horizontal plane. A pair of cylindrical oblique through holes are drilled at the closest point between the two adjacent cover electrodes (2). The cylindrical oblique through holes penetrate the second insulating layer (32), the first insulating layer (31), and the corona discharge cathode (4). Therefore, the corona discharge cathode (4) has cylindrical oblique through holes. This pair of cylindrical oblique through holes with close proximity and different inclination directions is a group. The center of the upper surface of the cylindrical oblique through holes is located on the perpendicular bisector of the line connecting the two relatively exposed electrodes (1) at their closest points. The centers of the upper surfaces of the pair of cylindrical oblique through holes are symmetrical about the line connecting them. The angle of inclination of each pair of cylindrical oblique through holes is symmetrical about the plane that passes through the perpendicular bisector and is perpendicular to the first insulating layer (31). A cylindrical corona discharge anode (5) is fixedly arranged under each through hole of the corona discharge cathode (4), and there is a space between the corona discharge cathode (4) and the cylindrical corona discharge anode (5); the corona discharge cathode (4) is fixed on the surface of the fuselage area that needs to be de-iced and is flush with the surface; the corona discharge cathode (4) is connected by a lead wire buried inside the fuselage skin; the cylindrical corona discharge anode (5) is fixed inside the fuselage and is electrically insulated from other parts of the fuselage except for the corona discharge cathode (4); The exposed electrode (1) is the high-voltage electrode of the dielectric barrier discharge plasma exciter; the exposed electrode (1) is distributed in a grid shape and is wavy in shape. The spacing of the grid is reasonably arranged according to the anti-icing area; the exposed electrode (1) includes multiple wavy electrodes arranged along the width direction on the second insulating layer (32). The protrusions of two adjacent exposed electrodes (1) are aligned with each other, and the recesses are aligned with each other. The spacing between the protrusions of two adjacent exposed electrodes (1) and the spacing between the recesses are equal; the length of the exposed electrode (1) is selected according to the requirements; the exposed electrode (1) is attached to the upper surface of the second insulating layer (32), and the projection of the exposed electrode (1) on the horizontal plane does not exceed the edge of the projection of the insulating layer on the horizontal plane; The masking electrode (2) is the low-voltage electrode of the dielectric barrier discharge plasma exciter; the masking electrode (2) is distributed in a grid shape and is wavy in shape. It is placed in the corresponding position to the exposed electrode (1). The wavy edges of the two overlap in the horizontal projection. The projection of the exposed electrode (1) on the horizontal plane does not overlap with the projection of the masking electrode (2) on the horizontal plane; the spacing of the grid is reasonably arranged according to the anti-icing area; the masking electrode (2) includes multiple wavy electrodes arranged along the width direction of the first insulating layer (31); the protrusions of two adjacent masking electrodes (2) are aligned with each other, and the recesses are aligned with each other; the spacing between the protrusions of two adjacent masking electrodes (2) and the spacing between the recesses are equal; the masking electrode (2) is attached between the first insulating layer (31) and the second insulating layer (32), and the projection of the masking electrode (2) on the horizontal plane does not exceed the edge of the projection of the insulating layer on the horizontal plane; The corona discharge cathode (4) is a thin cuboid shape. Multiple cylindrical oblique through holes are opened from top to bottom on its upper surface. Each pair of adjacent cylindrical oblique through holes forms a group. In the longitudinal direction, the odd-numbered rows of cylindrical oblique through holes have the same tilt direction and tilt angle. Their axes are parallel to each other and lie in the same horizontal vertical plane perpendicular to the front of the corona discharge cathode (4). The even-numbered rows of cylindrical oblique through holes have the same tilt direction and tilt angle. The tilt direction of the odd-numbered rows of cylindrical oblique through holes is symmetrical to the tilt direction of the even-numbered rows about the longitudinal vertical plane perpendicular to the front of the corona discharge cathode (4). The corona discharge anode (5) is coaxial with the lower surface circle of the cylindrical oblique through hole, and each corona discharge anode (5) corresponds to the cylindrical through hole on the corona discharge cavity plate.

2. The surface convection heat transfer enhanced plasma anti-icing device as described in claim 1, characterized in that, The exposed electrode (1) has a width of 1mm-10mm and a thickness of 0.06mm-0.2mm; the covered electrode (2) has a width of 1mm-10mm and a thickness of 0.06mm-0.2mm.

3. The surface convection heat transfer enhanced plasma anti-icing device as described in claim 2, characterized in that, The closest distance between the protrusions of two adjacent bare electrodes (1) is 7 mm; the material of the bare electrode (1) is copper foil, and the width of the bare electrode (1) is 2 mm; The thickness is 0.08mm; The closest distance between the protrusions of two adjacent cover electrodes (2) is 5 mm; the material of the cover electrode (2) is copper foil, and the width of the cover electrode (2) is 2 mm; The thickness is 0.08mm; The corona discharge cathode (4) is made of copper, with a length and width of 50 mm and 45 mm respectively, and a thickness of 3 mm. The diameter of the cylindrical oblique through holes on the corona discharge cathode (4) is 3 mm. The distance between the centers of each group of corona discharge cylindrical oblique through holes on the upper surface of the corona discharge cathode (4) is 4 mm. In the length direction, the distance between the center of the first and last cylindrical oblique through holes and the edge of the corona discharge cathode (4) is 2.5 mm. In the width direction, the distance between the first and last cylindrical oblique through holes and the edge of the corona discharge cathode (4) is 8 mm. The corona discharge anode (5) is a solid corona needle made of copper or tungsten; the corona discharge anode (5) is a cylinder with a diameter of 1 mm and a height of 2 mm; the upper and lower circular surfaces of the corona discharge anode (5) are parallel to the horizontal plane, and the corona discharge cathode (4) and the cylindrical corona discharge anode (5) are spaced 2 mm apart.

4. The surface convection heat transfer enhanced plasma anti-icing device as described in claim 3, characterized in that, There are 14 cylindrical through holes in total.

5. The surface convection heat transfer enhanced plasma anti-icing device as described in claim 1, characterized in that, Both the first insulating layer (31) and the second insulating layer (32) are made of high-temperature resistant composite materials.

6. The surface convection heat transfer enhanced plasma anti-icing device as described in claim 5, characterized in that, Both the first insulating layer (31) and the second insulating layer (32) are made of three or more layers of polyimide tape bonded together.

7. The surface convection heat transfer enhanced plasma anti-icing device as described in claim 1, characterized in that, The electrical connections for this device are as follows: The exposed electrode (1) is connected to the high-voltage end of the airborne pulsed plasma power supply (6) via a wire, and the covered electrode (2) is connected to the low-voltage end of the airborne pulsed plasma power supply (6) via a wire. The positive terminal of the high voltage DC power supply (7) is connected to the electrode of the corona discharge anode (5), and the negative terminal is connected to the corona discharge cathode (4).

8. The surface convection heat transfer enhanced plasma anti-icing device as described in claim 7, characterized in that, (7) Select a high voltage DC power supply with a voltage > 8kV; The high-voltage DC power supply (7) is located inside the cabin and is connected to the corona discharge anode (5) by a lead wire from the inside of the wing skin; the corona discharge cathode (4) is grounded by a lead wire through a perforated hole at the bottom.

9. A surface convection heat transfer enhanced plasma anti-icing method, based on the surface convection heat transfer enhanced plasma anti-icing device as described in any one of claims 1 to 8, characterized in that, Specifically as follows: The entire surface convection heat transfer enhanced plasma anti-icing device is embedded inside the surface that needs anti-icing and de-icing, with the upper surface of the device flush with the de-icing surface; the anti-icing and de-icing devices are flexibly arranged according to the areas of the aircraft surface that are difficult to ic. When supercooled water droplets impact the wing, the onboard pulsed plasma power supply (6) and high-voltage DC power supply (7) are activated, forming dielectric barrier discharge plasma in the gap between adjacent electrode strips of the exposed electrode (1) and the covered electrode (2). At the corona discharge cathode (4), each set of oblique through-holes ejects oblique jets that couple to form a spirally rising normal vortex. The nanosecond pulsed dielectric barrier discharge plasma has the effect of instantaneously heating the air and the wall surface. The normal vortex jet generated by the corona discharge can penetrate to a higher position on the surface, significantly increasing the air velocity on the wall and promoting convective heat transfer. Simultaneously, the normal vortex also draws the plasma generated by the DBD from... The upward lifting of the wall attachments increases the thickness of the plasma zone, thereby increasing the heating time for supercooled water droplets in the incoming flow before they impact the wall. The airflow generated by the corona discharge is also hot air with a certain temperature, which can further enhance the heating effect. The protruding parts of the wave-shaped DBD high-voltage electrodes placed opposite each other on both sides of the cylindrical oblique through-hole are aligned with the center of the normal vortex, generating a concentrated electric field at the vortex, making the discharge stronger and forming a local high-heat zone. The vortex then transmits the local high-heat zone outward, enhancing the anti-icing capability. These multiple effects ensure that supercooled water droplets do not freeze on the wing surface, achieving the purpose of anti-icing.

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