Surface convective heat transfer enhanced plasma ice preventing and removing device and method

Abstract

The surface convective heat transfer enhanced plasma ice preventing and removing device comprises an exposed electrode (1), a covering electrode (2), an insulating layer (3), a corona discharge cathode (4) and a corona discharge anode (5), and the exposed electrode (1) and the covering electrode (2) are both wavy electrodes. The bare electrode (1) is connected with the high-voltage end of the airborne pulse plasma power supply (6) through a wire, and the covering electrode (2) is connected with the low-voltage end of the airborne pulse plasma power supply (6) through a wire. The invention further provides a surface convective heat transfer enhanced plasma ice preventing and removing method. The exciter can generate plasmas at the exposed electrode (1) and the inclined through hole of the corona discharge cathode (4), and two plasma jets are coupled to form a spiral rising normal vortex, so that the wall surface air velocity is greatly improved, the thickness of a plasma area is increased, and convective heat transfer is promoted. According to the invention, the discharge intensity and density can be adjusted in real time according to the working condition so as to adapt to the anti-icing and deicing requirements under different working conditions, and the engineering application prospect is good.

Description

Technical Field

[0001] The invention belongs to an aircraft surface anti-icing device and method, relates to dielectric barrier discharge and corona discharge, and specifically relates to a surface convection heat transfer enhanced plasma anti-icing device and method. Background Art

[0002] When an aircraft flies under icing weather conditions, supercooled water droplets in the clouds will hit the windward surface of aircraft components and freeze quickly. Ice on key aircraft components will seriously affect the aircraft's maneuverability, stability and safety. For example, ice on the leading edge of the wing and tail will destroy the aerodynamic shape, reduce lift, increase drag, and seriously affect aerodynamic performance; ice on the engine lip will reduce engine efficiency and thrust, and in severe cases will damage the engine blades and cause them to stop working; ice on the windshield will reduce its clarity, causing certain safety hazards during flight; ice on instrument sensors (such as speed sensors) will cause equipment failure or data distortion, misleading the pilot's driving, and in severe cases causing the aircraft to crash. Therefore, the parts of the aircraft that are prone to icing must be de-iced to improve the safety performance of the aircraft.

[0003] At present, the main anti-icing methods include thermal deicing system, mechanical deicing system and super-hydrophobic material deicing system. According to the heat source, the thermal deicing system can be divided into electric thermal deicing system and gas thermal deicing system. The electric thermal deicing system has high reliability and is easy to implement, but its system structure is complex, heavy, has a low heating rate and low energy utilization rate; the pneumatic anti-icing technology has a simple principle and works reliably, but its air intake from the engine or auxiliary engine will affect the engine performance, has a large thermal inertia, slow response, and low energy utilization rate; super-hydrophobic materials can reduce the adhesion between the ice layer and the surface, delay the freezing of droplets, etc., but its preparation process is complex and the production cost is high. In low temperature and high humidity environment, it will face problems such as loss of hydrophobicity and poor durability, and its reliability is not high. At present, plasma deicing technology is developing rapidly. As an active deicing technology, plasma deicing technology has the advantages of simple structure, fast response, wide bandwidth, and easy automation. However, the common dielectric barrier discharge plasma deicing has high energy consumption and low efficiency, which restricts its technical application. Summary of the invention

[0004] In view of the shortcomings of the prior art, the present invention provides a surface convection heat transfer enhanced plasma anti-icing device, comprising a bare 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 is a thin rectangular parallelepiped structure, and its projection on the horizontal plane coincides with the projection of the corona discharge cathode 4 on the horizontal plane.

[0006] The dielectric barrier discharge covering electrode 2 is evenly arranged on the upper surface of the first insulating layer 31, serving as a dielectric barrier discharge cathode;

[0007] A second insulating layer 32 is added to the upper surface of the cover electrode 2. The second insulating layer 32 is completely 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 bare 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 a dielectric barrier discharge anode, the masking electrode 2 coincides with the edge of the bare electrode 1, and the projection of the bare electrode 1 on the horizontal plane does not coincide with the projection of the masking electrode 2 on the horizontal plane;

[0009] The exposed electrode 1 and the covered electrode 2 are both wavy electrodes; the arrangement of the exposed electrode 1 and the covered electrode 2 is in the form of 12-N*212-21, where N is a positive integer, where "1" represents a bare electrode 1 and "2" represents a covered electrode 2. In addition to the special arrangement at the two ends, there are N groups of "121 arrangement" in the middle; the exposed electrodes 1 and the covered electrodes 2 are grouped according to the intervals. Except for the two outermost groups, each group of electrodes is composed of three electrodes with exactly the same shape from left to right: the first covered electrode 2, the exposed electrode 1, the second covered electrode 2, and the three electrodes are arranged in a circle. The left and right edges of the electrodes are close to each other along the curved direction, the right edge of the first covered 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 covered electrode 2 on the horizontal plane; the two outermost groups of electrodes are: the leftmost group includes exposed electrode 1 and covered electrode 2 from left to right, and the right edge of the exposed electrode 1 coincides with the projection of the left edge of the covered electrode 2 on the horizontal plane; the rightmost group includes covered electrode 2 and exposed electrode 1 from left to right, and the right edge of the covered electrode 2 coincides with the projection of the left edge of the exposed electrode 1 on the horizontal plane;

[0010] A pair of cylindrical oblique through holes is formed at the middle position of the closest distance between the left and right adjacent covered electrodes 2 and the middle position between the two, and the cylindrical oblique through holes 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; this pair of cylindrical oblique through holes at close distances and with different inclination directions is a group, and the center of the cylindrical oblique through hole is located on the midpoint perpendicular line of the line connecting the two relatively exposed electrodes 1 at the closest distance, and the center of the upper surface of the pair of cylindrical oblique through holes is symmetrical about the line; the inclination angle of each pair of cylindrical oblique through holes is symmetrical about the plane passing through the midpoint perpendicular line and 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 deiced and kept flush with the surface, the corona discharge cathode 4 is connected through a lead buried in the fuselage skin, and the cylindrical corona discharge anode 5 is fixed inside the fuselage and is electrically insulated from other fuselage parts except 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, including 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 a bare electrode 1; the projections of the bare electrode 1, the covered electrode 2, and the corona discharge cathode 4 on the horizontal plane do not exceed the projection edge of the insulating layer on the horizontal plane;

[0013] The exposed electrode 1 is a high-voltage electrode of a dielectric barrier discharge plasma exciter; the exposed electrode 1 is distributed in a grid shape and is wavy as a whole, and the spacing of the grid is reasonably arranged according to the anti-deicing area; the exposed electrode 1 includes a plurality of wavy electrodes arranged along the width direction on the second insulating layer 32, and the protrusions of two adjacent exposed electrodes 1 are opposite to the protrusions, and the recesses are opposite to the recesses, and the spacing between the protrusions and the recesses of the two adjacent exposed electrodes 1 are equal; the length of the exposed electrode 1 is selected according to demand; 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 projection edge of the insulating layer on the horizontal plane;

[0014] The covered electrode 2 is a low-voltage electrode of the dielectric barrier discharge plasma exciter; the covered electrode 2 is distributed in a grid shape and is wavy as a whole. It is placed at a corresponding position corresponding to the exposed electrode 1, and the wavy edges of the two overlap in horizontal projection, and the projection of the exposed electrode 1 on the horizontal plane does not overlap with the projection of the covered electrode 2 on the horizontal plane; the spacing of the grid is reasonably arranged according to the anti-deicing area; the covered electrode 2 includes a plurality of wavy electrodes arranged along the width direction of the first insulating layer 31; the protrusions of two adjacent exposed electrodes 1 are opposite to the protrusions, and the recesses are opposite to the recesses; the spacing between the protrusions and the recesses of two adjacent covered electrodes 2 are equal; 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 projection edge of the insulating layer on the horizontal plane;

[0015] The corona discharge cathode 4 is in the shape of a thin rectangular parallelepiped, and a plurality of cylindrical oblique through holes are opened on its upper surface from top to bottom, and every two adjacent cylindrical oblique through holes form a group. When viewed longitudinally, the inclination direction and inclination angle of the cylindrical oblique micropores in odd-numbered rows are the same, and their axes are parallel to each other and in the same horizontal vertical plane perpendicular to the front face of the corona discharge cathode 4; the inclination angle and inclination angle of the cylindrical oblique micropores in even-numbered rows are the same, and the inclination direction of the cylindrical oblique micropores in odd-numbered rows is symmetrical with the inclination direction of the even-numbered rows about the longitudinal vertical plane perpendicular to the front face of the corona discharge cathode 4;

[0016] The corona discharge anode 5 is coaxial with the lower surface of the cylindrical oblique through hole, and each corona discharge anode 5 corresponds to the 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 1 mm-10 mm and a thickness of 0.06 mm-0.2 mm; the covered electrode 2 has a width of 1 mm-10 mm and a thickness of 0.06 mm-0.2 mm.

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

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

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

[0021] The corona discharge cathode 4 is made of copper, and its length and width are 50 mm and 45 mm respectively; the thickness is 3 mm; the diameter of the cylindrical oblique through hole on the corona discharge cathode 4 is 3 mm; the distance between the center 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 separated by a space of 2 mm.

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

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

[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 present invention, the device is electrically connected as follows:

[0027] The exposed electrode 1 is connected to the high voltage end of the airborne pulse plasma power supply 6 through a wire, and the covered electrode 2 is connected to the low voltage end of the airborne pulse plasma power supply 6 through a wire;

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

[0029] In yet another embodiment of the present invention,

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

[0031] The high voltage DC power supply 7 selects a high voltage DC power supply with a voltage>8kV;

[0032] The high voltage DC power supply 7 is arranged inside the cabin, and is connected to the corona discharge anode 5 through a lead from the inner side of the wing skin; the corona discharge cathode 4 is grounded through a lead through a hole at the bottom.

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

[0034] The whole surface convection heat transfer enhanced plasma anti-icing device is embedded in the surface that needs to be anti-iced, and the upper surface of the device is flush with the deicing surface; the anti-icing device is flexibly arranged according to the area on the aircraft surface that is easy to ice;

[0035] When the supercooled water droplets hit the wing, the onboard pulse plasma power supply 6 and the high-voltage DC power supply 7 are turned on, and a dielectric barrier discharge plasma is formed in the gap between the adjacent electrode strips of the exposed electrode 1 and the masked electrode 2. At the corona discharge cathode 4, each group of oblique through holes ejects oblique jets, which are coupled to form a spirally rising normal vortex. The nanosecond pulse dielectric barrier discharge plasma has the effect of instantly heating the air and the wall. The normal vortex jet generated by the corona discharge can penetrate into a higher position on the surface, greatly increasing the wall air flow rate and promoting convective heat transfer. At the same time, the normal vortex also pushes the plasma generated by the DBD from the wall to the The vortex is lifted upward to increase the thickness of the plasma zone, thereby increasing the heating time before the supercooled water droplets in the incoming flow hit the wall; the airflow generated by the corona discharge itself is also hot air with a certain temperature, which can also further enhance the heating effect; the relatively placed wavy DBD high-voltage electrode protrusions on both sides of the cylindrical oblique through hole are relative and aligned with the center of the above-mentioned normal vortex, generating an electric field concentration at the vortex, making the discharge there stronger and forming a local high-heat area; the vortex then transfers the local high-heat area outward to enhance the anti-icing capability; multiple actions ensure that the supercooled water droplets cannot freeze on the wing surface, thereby achieving the anti-icing purpose.

[0036] In order to further improve the anti-icing efficiency of plasma, the present invention introduces the corona blowing effect in the DBD discharge, and uses the corona discharge to ionize the air to form charged particles that move at high speed under the action of the electric field, forming a normal ion wind, promoting the propagation of DBD surface heating into the air, strengthening the convective heat transfer effect, and thus improving the anti-icing efficiency and reducing energy consumption. Since the mechanical efficiency of corona discharge is one order of magnitude higher than that of DBD, the convective heat transfer effect generated by corona discharge is stronger. On this basis, the oblique jets ejected from the adjacent oblique through holes of the corona discharge are coupled to form a spirally rising normal vortex, further enhancing the mixing of the hot air on the exciter surface and the low-temperature incoming flow, thereby further enhancing the convective heat transfer.

[0037] At the same time, in order to further enhance the convective heat transfer and air heating effect generated by the above-mentioned corona discharge, the DBD electrode is designed to be wavy, and the DBD discharge is concentrated at the corona blowing point, so that the discharge at the vortex point is stronger, and the temperature there is increased, thereby enhancing the heating effect in the space above the exciter. In addition, the airflow generated by the corona discharge itself has a certain temperature of hot air, which can also further enhance the heating effect. Combining the above-mentioned design principles, the present invention can effectively promote surface convective heat transfer, increase the spatial thickness of the heating zone above the exciter, and then increase the heating time before the supercooled water droplets in the convective flow hit the wall surface, thereby enhancing the anti-icing capability.

[0038] Compared with the invention patent "Multi-layer array microporous discharge plasma generating device and generating method" (publication number: CN113543442A), since the patent does not have a unidirectional electric field and cannot generate a jet, it cannot achieve the convective heat transfer promotion effect formed by the present invention, while the present invention uses corona discharge with high mechanical efficiency. Compared with traditional hot air jet deicing and electric heating anti-icing, the present invention does not damage engine performance, has a simple structure, rapid response, and a wide working frequency band; compared with the popular super-hydrophobic material passive anti-icing method, the present invention belongs to an active method, which is more convenient and more environmentally adaptable, and can adjust the discharge intensity and density in real time according to the working conditions to meet the anti-icing needs under different working conditions. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0040] Figure 2 A side view showing a surface convection heat transfer enhanced plasma deicing device;

[0041] Figure 3 A top view showing the arrangement of covered electrodes of a surface convection heat transfer enhanced plasma deicing device;

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

[0043] Figure 5 A top view showing a surface convection heat transfer enhanced plasma anti-icing device;

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

[0045] Figure 7 A schematic diagram of a bare electrode and a covered electrode of a dielectric barrier discharge is shown;

[0046] Figure 8 A schematic diagram of the connection circuit of the present invention is shown. Description of the drawings:

[0048] 1 Dielectric barrier discharge exposed electrode 2 Dielectric barrier discharge covered electrode 3 Insulation layer 4 Corona discharge cathode 5 Corona discharge anode 6 Pulse plasma power supply 7 High voltage DC power supply 8 Plasma DETAILED DESCRIPTION

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

[0050] A first insulating layer 31 is added on the corona discharge cathode 4 of a 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.

[0051] The dielectric barrier discharge cover electrode 2 is evenly arranged on the upper surface of the first insulating layer 31, serving as a dielectric barrier discharge cathode. Figure 1 , Figure 2 , Figure 3 As shown ( Figure 1 , Figure 2 This is a perspective view of the device. Figure 3 To cover the actual top view of the electrode arrangement).

[0052] A second insulating layer 32 is added on the upper surface of the cover electrode 2. The second insulating layer 32 is completely identical to 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 (such as Figure 1 As shown, the edges of the covered electrode 2 and the exposed electrode 1 overlap, and the projection of the exposed electrode 1 on the horizontal plane does not overlap with the projection of the covered electrode 2 on the horizontal plane), serving as a dielectric barrier discharge anode.

[0054] Both the exposed electrode 1 and the covered electrode 2 are wavy electrodes, such as Figure 7 As shown. The arrangement of the masking electrode 2 is as follows Figure 3 As shown. The arrangement of the exposed electrode 1 and the covered electrode 2 is in the form of 12-N*212-21 (N is a positive integer), where "1" represents a bare electrode 1 and "2" represents a covered electrode 2. Except for the special arrangement at the two ends, there are N groups of "121 arrangement" in the middle. Figure 1 As shown, the exposed electrode 1 and the covered electrode 2 are grouped at intervals. Except for the two outermost groups, each group of electrodes is composed of three electrodes of exactly the same shape from left to right: the first covered electrode 2, the exposed electrode 1, and the second covered electrode 2. The three electrodes are adjacent to each other along their curved left and right edges. For example, the right edge of the first covered 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 covered electrode 2 on the horizontal plane. The two outermost groups of electrodes are: the leftmost includes the exposed electrode 1 and the covered electrode 2 from left to right, and the right edge of the exposed electrode 1 coincides with the projection of the left edge of the covered electrode 2 on the horizontal plane; the rightmost includes the covered electrode 2 and the exposed electrode 1 from left to right, and the right edge of the covered electrode 2 coincides with the projection of the left edge of the exposed electrode 1 on the horizontal plane. The dielectric barrier discharge generates plasma from the bare electrode 1 to the covered electrode 2 at the intersection of the exposed electrode 1 and the covered electrode 2.

[0055] A pair of cylindrical oblique through holes (such as 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, such as Figure 4 This pair of cylindrical oblique through holes at close distances and with different inclination directions is a group, the center of the cylindrical oblique through hole is located on the perpendicular bisector of the line connecting the two closest points (protrusions) of the exposed electrodes 1, and the center of the upper surface of the pair of cylindrical oblique through holes is symmetrical about the line, as shown in FIG. Figure 5 As shown (the protruding part is circled in the figure), the inclination angle of each pair of cylindrical oblique through holes is symmetrical about the plane passing through the perpendicular midline 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, and the space between the corona discharge cathode 4 and the cylindrical corona discharge anode 5 is 2 mm. Figure 6 As shown. Plasma 8 is generated between the corona discharge cathode 4 and the corona discharge anode 5, as shown in FIG. Figure 2 The corona discharge cathode 4 is fixed on the surface of the fuselage area that needs to be protected from deicing and is kept flush with the surface. The corona discharge cathode 4 is connected through a lead 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 the corona discharge cathode 4.

[0057] Therefore, the surface convection heat transfer enhanced plasma anti-icing device includes a six-layer structure from bottom to top, including a corona discharge anode 5, a corona discharge cathode 4, a first insulating layer 31, a covering electrode 2, a second insulating layer 32, and a bare electrode 1. Figure 1 , Figure 2 The projections of the bare electrode 1, the covered electrode 2 and the corona discharge cathode 4 on the horizontal plane will not exceed the projection edge of the insulating layer on the horizontal plane.

[0058] The exposed electrode 1 is a high voltage electrode of a dielectric barrier discharge plasma actuator. The exposed electrode 1 is distributed in a grid shape and is wavy in shape as a whole. Figure 7 As shown, the grid spacing can be reasonably arranged according to the anti-deicing area. The exposed electrode 1 includes a second insulating layer 32 along the width direction (the width direction is Figure 3A plurality of wavy electrodes are arranged in the longitudinal direction of the second insulating layer 32, with the protrusions of two adjacent exposed electrodes 1 facing the protrusions, and the recesses facing the recesses. The closest distance between the protrusions of two adjacent exposed electrodes 1 is 7mm, and the spacing between the protrusions and the spacing between the recesses of two adjacent exposed electrodes 1 are equal. In one embodiment of the present invention, the material of the exposed electrode 1 is copper foil (a metal or metal alloy material with a relatively high conductivity), the width of the exposed electrode 1 is 1mm-10mm, preferably 2mm; the thickness is 0.06mm-0.2mm, preferably 0.08mm; the length of the exposed electrode 1 can be selected according to demand, for example, whether it is necessary 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 will not exceed the projection edge of the insulating layer on the horizontal plane.

[0059] The cover electrode 2 is a low-voltage electrode of the dielectric barrier discharge plasma exciter. The cover electrode 2 is distributed in a grid shape and is wavy in shape as a whole. Figure 7 As shown, it is placed at the corresponding position corresponding to the exposed electrode 1, and the wavy edges of the two coincide with each other in 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, as shown in FIG. Figure 1 , Figure 2 As shown ( Figure 1 , Figure 2 The grid spacing can be reasonably arranged according to the anti-deicing area. The masking electrode 2 includes a first insulating layer 31 along the width direction (the width direction is Figure 3 A plurality of wavy electrodes are arranged in the longitudinal direction of the cover electrode 2; the protrusions of two adjacent exposed electrodes 1 face the protrusions, and the recesses face the recesses. The spacing between the protrusions and the recesses of two adjacent cover electrodes 2 are equal. The closest distance between the protrusions of two adjacent cover electrodes 2 is 5mm. In one embodiment of the present invention, the material of the cover electrode 2 is copper foil (a metal or metal alloy material with a relatively high conductivity), the width of the cover electrode 2 is 1mm-10mm, preferably 2mm; the thickness is 0.06mm-0.2mm, preferably 0.08mm. The cover electrode 2 is attached between the first insulating layer 31 and the second insulating layer 32, and the projection of the cover electrode 2 on the horizontal plane does not exceed the projection edge of the insulating layer on the horizontal plane.

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

[0061] The corona discharge cathode 4 is in the shape of a thin rectangular parallelepiped, such as Figure 4As shown, it is made of conductive metals such as copper, silver, and tungsten. As mentioned above, the upper surface of the corona discharge cathode 4 is provided with a plurality of cylindrical oblique through holes from top to bottom, and each two adjacent cylindrical oblique through holes form a group, such as Figure 1 As shown, from top to bottom, there are ten rows in total, and the inclination direction and inclination angle of the odd-numbered rows of cylindrical oblique micropores are the same, their axes are parallel to each other and in the same horizontal vertical plane perpendicular to the front of the corona discharge cathode 4; the inclination angles of the even-numbered rows of cylindrical oblique micropores are the same, and the inclination direction of the odd-numbered rows of cylindrical oblique micropores is symmetrical with the inclination direction 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 arranged inside the cabin and connected to the corona discharge cathode 4 by a lead from the inner side of the wing skin. The corona discharge cathode 5 is grounded by a lead through a hole at the bottom. All other connections of the corona discharge anode 5 adopt conventional technical means in this field, which will not be repeated.

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

[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 power is turned on, the corona discharge cathode 4 and the corona discharge anode 5 generate plasma 8. The corona discharge anode 5 is usually made of copper or tungsten. In a specific embodiment of the present invention, the corona discharge anode 5 is made of copper, and its diameter is 1mm and the height is 2mm. Each corona discharge anode 5 corresponds to the cylindrical through hole on the corona discharge cavity plate, which is parallel to the horizontal plane and the distance is 2mm.

[0064] The pulse plasma power supply 6 adopts an airborne pulse plasma power supply; the exposed electrode 1 is connected to the high voltage end of the airborne pulse plasma power supply 6 through a wire, and the covered electrode 2 is connected to the low voltage end of the airborne pulse plasma power supply 6 through a wire. The volume and weight of the pulse plasma power supply should be as small as possible to reduce the structural weight cost of the device and adapt to application scenarios with limited space and load, such as drones.

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

[0066] The surface convection heat transfer enhanced plasma deicing device and method of the present invention uses copper foil (a metal or metal alloy with a relatively high conductivity coefficient) as the exposed electrode and the covered electrode, and a multilayer polyimide or a high-temperature resistant composite material with a comparable dielectric constant as the insulating layer. The exposed electrode is connected to the high-voltage end of the airborne pulse plasma power supply through a wire, and the covered electrode is connected to the low-voltage end of the airborne pulse plasma power supply through a wire. Copper (a metal or metal alloy with a relatively high conductivity coefficient) 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 through a wire, and the corona discharge cathode is connected to the low-voltage end of the airborne high-voltage DC power supply through a wire. The entire surface convection heat transfer enhanced plasma deicing device is embedded in the surface that needs to be deiced, and the upper surface of the device is flush with the deicing surface. The deicing device can be flexibly arranged according to the icing difficulty area on the aircraft surface to ensure rapid response and scientific and reasonable energy utilization.

[0067] Based on the above device, the present invention also proposes a plasma anti-icing method based on surface convection heat transfer enhancement, which is as follows:

[0068] When the supercooled water droplets hit the wing, the airborne pulse plasma power supply 6 and the high-voltage DC power supply 7 are turned on, and a dielectric barrier discharge plasma is formed in the gap between the adjacent electrode strips of the exposed electrode 1 and the masked electrode 2. At the corona discharge cathode 4, each group of oblique through holes ejects oblique jets that couple to form a spirally rising normal vortex. Nanosecond pulse dielectric barrier discharge plasma has the effect of instantly heating the air and the wall surface; the normal vortex jet generated by the corona discharge can penetrate into a higher position on the surface, greatly increase the wall air flow rate, and promote convective heat transfer. At the same time, the normal vortex also lifts the plasma generated by the DBD from the wall attachment upward, increases the thickness of the plasma zone, and then increases the heating time before the supercooled water droplets in the convective flow hit the wall surface. Again, the airflow generated by the corona discharge itself also has a certain temperature of hot air, which can also further enhance the heating effect. In addition, the relatively placed wavy DBD high-voltage electrode protrusions on both sides of the cylindrical oblique through hole are relatively and aligned with the center of the above-mentioned normal vortex, generating an electric field concentration at the vortex, making the discharge there stronger, forming a local high-heat zone. The vortex then transfers the local high-heat area outward to enhance the anti-icing capability. The multiple effects ensure that the supercooled water droplets cannot freeze on the wing surface, achieving the purpose of anti-icing.

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

[0070] Among the currently popular technologies, aircraft anti-icing methods are mostly electric thermal anti-icing, gas thermal anti-icing and simple passive anti-icing methods based on hydrophobic materials. In the aircraft anti-icing technology using plasma discharge, the discharge method used is mostly dielectric barrier discharge, and there is no technology using corona discharge for aircraft anti-icing.

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

[0072] 1. Stronger adaptability. Compared with the popular hydrophobic material anti-icing method, the surface convection heat transfer enhanced plasma anti-icing device and method proposed in the present invention is an active method. It can adjust the discharge intensity and density in real time according to the changes in the icing intensity in actual flight to meet the needs of aircraft anti-icing. It can effectively adapt to the rapidly changing weather conditions in actual flight and always maintain the best flight state of the aircraft. The adaptability and practicality have been qualitatively enhanced, and it is suitable for anti-icing under extremely severe meteorological conditions.

[0073] 2. Simple structure and light weight. Compared with the hot air anti-icing method, it does not need to draw air from the engine, the air path is shorter, and the engine performance is not damaged. Compared with the electric heat-based anti-icing method, the surface convection heat transfer enhanced plasma anti-icing device and method proposed in the present invention has a simple structure, light weight, simple maintenance, and easy replacement. It can reduce the weight of the aircraft and improve the performance of the aircraft. It can have stronger application scenarios in aircraft with limited space and load, such as drones.

[0074] 3. Rapid response. Since the electrodes of the present invention can be regulated by power supply electrical signals, compared with other anti-icing devices such as gas-heat anti-icing and hydrophobic materials, the surface convection heat transfer enhanced plasma anti-icing actuator of the present invention has the advantages of simple structure, high frequency response, and fast response speed. This rapid response capability enables the present invention to reach the optimal design state more quickly and achieve better anti-icing effect.

Claims

1. A surface convection heat transfer enhanced plasma anti-icing device, characterized in that: The device comprises a bare electrode (1), a covered electrode (2), an insulating layer (3), a corona discharge cathode (4), and a corona discharge anode (5), wherein: Adding a first insulating layer (31) on a corona discharge cathode (4) of a rectangular thin metal plate, wherein the first insulating layer (31) is a thin rectangular parallelepiped structure, and its projection on a horizontal plane coincides with the projection of the corona discharge cathode (4) on the horizontal plane; A dielectric barrier discharge covering electrode (2) is evenly arranged on the upper surface of the first insulating layer (31) to serve as a dielectric barrier discharge cathode; A second insulating layer (32) is added to the upper surface of the masking electrode (2), wherein the second insulating layer (32) is completely identical to 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 as a dielectric barrier discharge anode at a position corresponding to the edge of the masking electrode (2) on the upper surface of the second insulating layer (32), the masking electrode (2) and the edge of the exposed electrode (1) overlap, and 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 exposed electrode (1) and the covered electrode (2) are both wavy electrodes; the arrangement of the exposed electrode (1) and the covered electrode (2) is in the form of 12-N*212-21, where N is a positive integer, wherein "1" represents one exposed electrode (1), and "2" represents one covered electrode (2). In addition to the special arrangement at the two ends, the middle is N groups of "121 arrangement"; the exposed electrodes (1) and the covered electrodes (2) are grouped according to the intervals, and except for the two outermost groups, each group of electrodes is composed of three electrodes of exactly the same shape from left to right: the first covered electrode (2), the exposed electrode (1), the second covered electrode (2), and the three electrodes Along the curved direction, the left and right edges are adjacent, the right edge of the first shielded electrode (2) and the left edge of the exposed electrode (1) are projected on the horizontal plane in an overlapping manner, and the right edge of the exposed electrode (1) and the left edge of the second shielded electrode (2) are projected on the horizontal plane in an overlapping manner; the two outermost groups of electrodes are: the leftmost group includes the exposed electrode (1) and the shielded electrode (2) from left to right, and the right edge of the exposed electrode (1) and the left edge of the shielded electrode (2) are projected on the horizontal plane in an overlapping manner; the rightmost group includes the shielded electrode (2) and the exposed electrode (1) from left to right, and the right edge of the shielded electrode (2) and the left edge of the exposed electrode (1) are projected on the horizontal plane in an overlapping manner; A pair of cylindrical oblique through holes is formed at the middle position of the closest distance between the left and right adjacent covered electrodes (2) and at the middle position between the two, and the cylindrical oblique through holes 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; the pair of cylindrical oblique through holes at close distances and with different inclination directions form a group, the center of the cylindrical oblique through hole is located on the perpendicular midline of the line connecting the closest distance between 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; the inclination angle of each pair of cylindrical oblique through holes is symmetrical about the plane passing through the perpendicular midline and 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 a space is provided 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 requiring deicing protection and is kept flush with the surface; the corona discharge cathode (4) is connected via 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 the corona discharge cathode (4); The surface convection heat transfer enhanced plasma anti-icing device comprises a six-layer structure from bottom to top, namely, 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 a bare electrode (1); the projections of the bare electrode (1), the covered electrode (2), and the corona discharge cathode (4) on a horizontal plane do not exceed the projection edge of the insulating layer on the horizontal plane; The exposed electrode (1) is a high-voltage electrode of a dielectric barrier discharge plasma actuator; the exposed electrode (1) is distributed in a grid shape and is wavy as a whole, and the grid spacing is reasonably arranged according to the anti-deicing area; the exposed electrode (1) includes a plurality of wavy electrodes arranged along the width direction on the second insulating layer (32), the protrusions of two adjacent exposed electrodes (1) are opposite to each other, and the recesses are opposite to each other, and the spacing between the protrusions and the spacing between the recesses of the two adjacent exposed electrodes (1) are equal; the length of the exposed electrode (1) is selected according to demand; 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 projection edge of the insulating layer on the horizontal plane; The covered electrode (2) is a low-voltage electrode of a dielectric barrier discharge plasma exciter; the covered electrode (2) is distributed in a grid shape and is wavy as a whole. It is placed at a corresponding position with the exposed electrode (1), and the wavy edges of the two overlap in horizontal projection, and the projection of the exposed electrode (1) on the horizontal plane does not overlap with the projection of the covered electrode (2) on the horizontal plane; the spacing of the grid is reasonably arranged according to the anti-deicing area; the covered electrode (2) includes a plurality of wavy electrodes arranged along the width direction of the first insulating layer (31); the protrusions of two adjacent exposed electrodes (1) face the protrusions, and the recesses face the recesses; the spacing between the protrusions and the recesses of two adjacent covered electrodes (2) are equal; 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 projection edge of the insulating layer on the horizontal plane; The corona discharge cathode (4) is in the shape of a thin rectangular parallelepiped, and a plurality of cylindrical oblique through holes are opened on its upper surface from top to bottom, and every two adjacent cylindrical oblique through holes form a group. When viewed longitudinally, the inclination direction and inclination angle of the cylindrical oblique micropores in odd-numbered rows are the same, and their axes are parallel to each other and are in the same horizontal vertical plane perpendicular to the front face of the corona discharge cathode (4); the inclination angle and inclination angle of the cylindrical oblique micropores in even-numbered rows are the same, and the inclination direction of the cylindrical oblique micropores in odd-numbered rows is symmetrical with the inclination direction of the even-numbered rows about the longitudinal vertical plane perpendicular to the front face 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 according to claim 1, characterized in that: The exposed electrode (1) has a width of 1 mm to 10 mm and a thickness of 0.06 mm to 0.2 mm; the covered electrode (2) has a width of 1 mm to 10 mm and a thickness of 0.06 mm to 0.2 mm.

3. The surface convection heat transfer enhanced plasma anti-icing device according to claim 2, characterized in that: The shortest distance between the protrusions of two adjacent exposed electrodes (1) is 7 mm; the material of the exposed electrodes (1) is copper foil, and the width of the exposed electrodes (1) is 2 mm; Thickness: 0.08mm; The closest distance between the protrusions of two adjacent covering electrodes (2) is 5 mm; the material of the covering electrodes (2) is copper foil, and the width of the covering electrodes (2) is 2 mm; Thickness: 0.08mm; The corona discharge cathode (4) is made of copper, and has a length and width of 50 mm and 45 mm respectively; a thickness of 3 mm; a diameter of the cylindrical oblique through hole on the corona discharge cathode (4) of 3 mm; a distance between the centers of each group of corona discharge cylindrical oblique through holes on the upper surface of the corona discharge cathode (4) of 4 mm; in the length direction, the distances between the centers of the first and last cylindrical oblique through holes and the edge of the corona discharge cathode (4) are 2.5 mm; in the width direction, the distances between the first and last cylindrical oblique through holes and the edge of the corona discharge cathode (4) are both 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 separated by a space of 2 mm.

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

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

6. The surface convection heat transfer enhanced plasma anti-icing device according to claim 5, characterized in that: The first insulating layer (31) and the second insulating layer (32) are both formed by bonding three or more layers of polyimide tape.

7. The surface convection heat transfer enhanced plasma anti-icing device according to claim 1, characterized in that: The device is electrically connected as follows: The exposed electrode (1) is connected to the high voltage end of the onboard pulse plasma power supply (6) through a wire, and the covered electrode (2) is connected to the low voltage end of the onboard pulse plasma power supply (6) through a wire; The positive electrode of the high-voltage direct current power source (7) is connected to the electrode of the corona discharge anode (5), and the negative electrode is connected to the corona discharge cathode (4).

8. The surface convection heat transfer enhanced plasma anti-icing device according to claim 7, characterized in that: The pulse plasma power supply (6) adopts an airborne pulse plasma power supply; High voltage DC power supply (7) selects a high voltage DC power supply with a voltage > 8kV; A high-voltage direct current power source (7) is arranged inside the cabin and connected to a corona discharge anode (5) via a lead from the inner side of the wing skin; a corona discharge cathode (4) is grounded via a lead through a hole in the bottom.

9. A surface convection heat transfer enhanced plasma deicing method, based on the surface convection heat transfer enhanced plasma deicing device according to any one of claims 1 to 8, characterized in that: The details are as follows: The whole surface convection heat transfer enhanced plasma anti-icing device is embedded in the surface that needs to be anti-iced, and the upper surface of the device is flush with the deicing surface; the anti-icing device is flexibly arranged according to the area on the aircraft surface that is easy to ice; When the supercooled water droplets hit the wing, the onboard pulse plasma power supply (6) and the high-voltage direct current power supply (7) are turned on, and a dielectric barrier discharge plasma is formed in the gap between the adjacent electrode strips of the exposed electrode (1) and the masked electrode (2). At the corona discharge cathode (4), each group of oblique through holes ejects oblique jets that couple to form a spirally rising normal vortex. The nanosecond pulse dielectric barrier discharge plasma has the effect of instantly heating the air and the wall. The normal vortex jet generated by the corona discharge can penetrate to a higher position on the surface, greatly increasing the wall air flow rate and promoting convective heat transfer. At the same time, the normal vortex also pushes the plasma generated by the DBD from the The wall attachment is lifted upward to increase the thickness of the plasma zone, thereby increasing the heating time before the supercooled water droplets in the incoming flow hit the wall; the airflow generated by the corona discharge itself is also hot air with a certain temperature, which can also further enhance the heating effect; the relatively placed wavy DBD high-voltage electrode protrusions on both sides of the cylindrical oblique through hole are relative and aligned with the center of the above-mentioned normal vortex, generating an electric field concentration at the vortex, making the discharge there stronger and forming a local high-heat area; the local high-heat area is then transferred outward by the vortex to enhance the anti-icing capability; multiple actions ensure that the supercooled water droplets cannot freeze on the wing surface, thereby achieving the anti-icing purpose.

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