CN113200141B - A kind of air suction type increasing device based on Lava tubular plasma - Google Patents

Abstract

The invention discloses a Lava tube-shaped plasma aspirating type increasing lift device, comprising two fixed flat plates arranged in parallel with each other, two plasma discharge unit installation platforms are arranged between the two fixed flat plates, and two fixed flat plates are arranged between two fixed plates. The flat plate and the two plasma discharge unit installation platforms together form a Lava tubular cavity. Plasma discharge units are arranged on the slope surfaces of the two plasma discharge unit installation platforms, and one side of the plasma discharge unit is connected to a high-voltage power supply. One side of the plasma discharge unit is grounded; the tapered section port of the Lava tubular cavity is the airflow inlet, the straight section port of the Lava tubular cavity is the airflow outlet, and the airflow outlet is provided with a first check valve; each plasma A second check valve is arranged on the installation platform of the discharge unit, and the second check valve prevents the outside air from entering the Lava tubular cavity. The device can achieve the purpose of increasing the lift of the aircraft by delaying the flow separation of the airfoil or the wing, changing the leading edge vortex structure and the vortex rupture.

Description

A kind of air suction type increasing device based on Lava tubular plasma

technical field

The invention belongs to the technical fields of aerodynamics, plasma physics and flow control, and in particular relates to a Lava tube-shaped plasma air suction type increasing device.

Background technique

With the development of science and technology, the consumption of fossil energy has increased, and carbon emissions have increased rapidly, resulting in continuous deterioration of the environment. Therefore, energy conservation and emission reduction has become a hot issue that has been widely concerned by all sectors of society. According to relevant researches, it is shown that installing a device to improve airfoil lift on an aircraft can increase the maximum lift coefficient of the aircraft and shorten the take-off and landing roll distance of the aircraft. The reduction in take-off and landing roll distances reduces fuel consumption. The survey found that among the operating costs of the aircraft, fuel costs account for about 30% of the total operating costs. Therefore, increasing the maximum lift coefficient of the aircraft and shortening the take-off and landing run distances of the aircraft can save the aircraft's energy consumption and reduce operating costs.

The research shows that when the aircraft is at a medium and small angle of attack, the airflow inevitably separates at the leading edge of the airfoil and generates a complex leading edge vortex structure, which affects the maximum lift coefficient of the aircraft. The commonly used mechanism of increasing lift is to delay the flow separation of airfoil or airfoil, change the leading edge vortex structure and vortex rupture, and change the flow from an unsteady flow state to a steady flow state, thereby improving the lift of the airfoil. Based on this control mechanism, many methods of increasing lift have been developed. According to whether the control method of increasing lift requires external energy input, the technology of increasing lift is mainly divided into active control technology and passive control technology. Among them, passive control technologies (such as micro-drums, micro-pits, vortex generators, etc.) have been fully researched and widely used, but they have limited potential to improve the performance of aircraft, and can only achieve effective control in a specific state. It cannot be applied to complex flow field control. Active flow control technology is to apply external energy to the flow field, which is coupled with the flow field on the surface of the wing to play a flow control role. Compared with passive control technology, the advantage of active control technology is that it can adaptively adjust the flow field in different states through closed-loop control, thereby achieving the purpose of wide-range flow control.

Air-breathing increased-lift flow control technology is one of many active control methods, which has been widely studied due to its advantages of high efficiency, fast response, and low additional resistance. Existing suction control methods mainly include pneumatic valves, dry powder inhalers, etc. Although most of the control methods are highly efficient, they cannot avoid problems such as large control systems and complex mechanical structures, which limit their further engineering applications.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a Laval tube-shaped plasma air-breathing increasing lift device, which can achieve the purpose of increasing the lift of the aircraft by delaying the flow separation of the airfoil or wing, changing the leading edge vortex structure and vortex rupture.

The technical scheme adopted in the present invention is that a plasma suction type increasing device based on Lava tube comprises two fixed flat plates arranged in parallel with each other, and two plasma discharge units are installed between the two fixed flat plates. The longitudinal section of the plasma discharge unit installation platform is a right-angled trapezoid, and the two plasma discharge unit installation platforms located between the two fixed flat plates are arranged in mirror symmetry, and the two fixed flat plates and the two plasma discharge unit installation platforms share the same A Lava tube-shaped cavity is enclosed, and the space enclosed by the slope surfaces of the two plasma discharge unit installation platforms and the two fixed flat plates constitutes the tapered section of the Lava tube-shaped cavity, and the two plasma discharge unit installation platforms are opposite to each other. The space enclosed by the wall surface of the two fixed flat plates and the two fixed flat plates constitute the straight section of the Lava tubular cavity. Plasma discharge units are installed on the slope surfaces of the two plasma discharge unit installation platforms, and one side of the plasma discharge units is connected to High-voltage power supply, one side of the plasma discharge unit is grounded; the tapered section port of the Lava tubular cavity is the airflow inlet, the straight section port of the Lava tubular cavity is the airflow outlet, and the airflow outlet is provided with a first check valve. A check valve prevents the outside air from entering the Lava tubular cavity; a second check valve is provided on each plasma discharge unit installation platform, one end of the second check valve faces the outside atmosphere, and the second check valve is The other end faces the Lava tubular cavity, and the second check valve prevents the outside air from entering the Lava tubular cavity.

The present invention is also characterized in that,

The plasma discharge unit includes a plate-shaped dielectric layer, one side of the plate-shaped dielectric layer is provided with a fork-shaped AlSi ₃ O ₄ mesh exposed electrode, and the other side of the plate-shaped dielectric layer is provided with several plate-shaped AlSi ₃ O ₄ meshes The fork-shaped AlSi ₃ O ₄ mesh-shaped exposed electrode is connected to the high-voltage power supply, and several plate-shaped AlSi ₃ O ₄ mesh-shaped covering electrodes are connected in parallel and then grounded; the fork-shaped AlSi ₃ O ₄ mesh-shaped exposed electrode faces the airflow side, and several A plate-type AlSi ₃ O ₄ mesh covering electrode is laid on the slope surface of the plasma discharge unit installation platform.

The high-voltage power supply voltage is 5kV-30kV, the waveform is fast rising and slow falling, and the period is 0.1ns-1ms.

The thickness of the plate type AlSi ₃ O ₄ mesh covering electrode is 0.01mm-1mm and the width is 5-20mm; the thickness of the fork type AlSi ₃ O ₄ mesh exposed electrode is 0.01mm-1mm, and the width of each forked part is 2-5mm.

The plate-shaped dielectric layer is an F4BM material dielectric layer.

The material of the fixed plate is plexiglass; the material of the plasma discharge unit mounting table is polytetrafluoroethylene.

The first check valve is a plate-shaped check valve; the second check valve is a conical check valve.

The beneficial effects of the present invention are:

(1) The present invention proposes a configuration of a suction-type lifting device based on the Lava tube-shaped plasma. By inducing the airflow inside the Lava tube-shaped cavity, the air inside the Lava tube-shaped cavity forms a negative pressure. There is a pressure difference between the air port and the outside atmospheric pressure. Under the action of the pressure difference, the gas is sucked into the pump cavity, delaying the flow separation of the airfoil or wing, changing the leading edge vortex structure and vortex rupture, and achieving the purpose of increasing the aircraft's lift.

(2) The present invention is based on a Laval tube-shaped plasma air suction type increasing device, an ion plasma air suction increasing device, which replaces the traditional mechanical device with a plasma exciter to induce airflow, and adopts fast rising and slow falling at the same time. It has the advantages of simple structure, short response time and low energy consumption.

(3) The present invention is based on a Lava tube-shaped plasma aspirating type increasing device, using a Lava tube-shaped cavity, according to the continuity assumption and Bernoulli's equation, when the power is turned on, the plasma discharge unit generates a jet, so that the The fluid velocity inside the Lava tubular cavity increases, causing the external gas to be sucked in at subsonic speed. At the same time, the gas is forced to accelerate as the Lava tubular cavity contracts. Under the same energy consumption conditions, it can generate a larger air intake and increase the control effect of the flow separation on the surface of the wing, so that the flow separation point is moved back and the lift of the aircraft is increased.

(4) The present invention is an air-inhalation type increasing device based on the Lava tubular plasma. Check valves are arranged up and down the Lava tubular cavity, and a check valve is arranged at the gas outlet to prevent the gas from being sucked back and further enhance the suction. efficiency.

(5) The present invention is based on a Lava tubular plasma air suction type increasing lift device, which adopts electrical signal control, has no complex control system and mechanical moving parts, has a fast response speed, can cooperate with a closed-loop control system, and can be adjusted in real time according to the state of the flow field. Input power, realize closed-loop control, reduce energy consumption, and improve control effect.

(6) The present invention is a plasma air suction type increasing lifter based on Lava tube shape, adopts a rectangular configuration, has good adaptability, and can flexibly arrange the suction device according to the airfoil surface structure and usage requirements.

(7) The device is designed to reduce energy consumption and operating costs, and is a green and low-carbon technology.

Description of drawings

1 is a schematic structural diagram of a Lava tube-shaped plasma aspirating type increasing device of the present invention;

2 is a view of the internal structure of a Lava tube-shaped plasma aspirating type increasing device of the present invention;

FIG. 3 is a schematic structural diagram of a plasma discharge unit mounting platform and a plasma discharge unit in a Laval tube-shaped plasma air suction type increasing device of the present invention;

FIG. 4 is the relative positional relationship between the fork-shaped AlSi ₃ O ₄ mesh-shaped exposed electrode, the plate-shaped dielectric layer and the plate-shaped AlSi ₃ O ₄ mesh-shaped covering electrode in a Laval tube-shaped plasma air suction type increasing lift device of the present invention. schematic diagram;

Fig. 5 is a kind of schlieren experiment of the present invention based on the Lava tube-shaped plasma air suction type increasing lift device without the power supply;

Fig. 6 is a kind of schlieren experiment of the present invention based on the power-on of the Lava tubular plasma air suction type increasing lift device;

Fig. 7 is a kind of piv experiment result of the present invention based on the Lava tubular plasma air suction type increasing lift device;

8 is a waveform diagram of the use of a pulsed high-voltage power supply based on a Lava tube-shaped plasma aspirating type increasing device of the present invention;

9 is a schematic diagram of the installation and arrangement of a Lava tubular plasma aspirating type increasing lift device according to the present invention;

10 is a schematic diagram of the flow field on the surface of the airfoil when a Lava tube-shaped plasma aspirating type increasing device of the present invention is not in operation;

11 is an experimental diagram of the airfoil surface flow field when a Lava tube-shaped plasma air suction type increasing device of the present invention is not in operation;

12 is a schematic diagram of the flow field on the surface of the airfoil when a Lava tube-shaped plasma aspirating type increasing device of the present invention is turned on and working;

FIG. 13 is an experimental diagram of the airfoil surface flow field when a Laval tube-shaped plasma air-breathing increasing lift device according to the present invention is turned on and working.

In the figure, 1. Fixed plate, 2. Plasma discharge unit installation platform, 3. Lava tubular cavity, 4. First check valve, 5. Second check valve, 6. Fork-shaped AlSi ₃ O ₄ mesh shape exposed electrode, 7. plate-shaped dielectric layer, 8. plate-shaped AlSi ₃ O ₄ mesh covered electrode, 9. bolt, 10. nut;

A. Lava tube-based plasma aspirating high-lift device, B. Air flow conduit.

Detailed ways

The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

As shown in Figures 1-4, the present invention includes two fixed flat plates 1 arranged in parallel with each other, and the distance between them is 50 mm; between the two fixed flat plates 1 Two plasma discharge unit installation platforms 2 are provided, and the two plasma discharge unit installation platforms 2 arranged between the two fixed flat plates 1 are fixed together by bolts 9 and nuts 10; The longitudinal section is a right-angled trapezoid, and the two plasma discharge unit mounting platforms 2 located between the two fixed flat plates 1 are arranged in mirror symmetry, and the two fixed flat plates 1 and the two plasma discharge unit mounting platforms 2 together form a Lava In the tubular cavity 3, the taper of the tapered part of the cavity is 15°; the slope surface of the two plasma discharge unit installation platforms 2 and the space enclosed by the two fixed flat plates 1 constitute the tapered section of the Lava tubular cavity 3, The opposite wall surfaces of the two plasma discharge unit installation platforms 2 and the space enclosed by the two fixed flat plates 1 constitute the straight section of the Lava tubular cavity 3 , and the slope surfaces of the two plasma discharge unit installation platforms 2 are both set There is a plasma discharge unit, one side of the plasma discharge unit is connected to the high-voltage power supply, and one side of the plasma discharge unit is grounded; It is an airflow outlet, and the airflow outlet is provided with a first check valve 4, which prevents the outside air from entering the Lava tubular cavity 3, and the lateral projection area of the first check valve 4 is the same as the airflow outlet area; Each plasma discharge unit installation platform 2 is provided with a second check valve 5, one end of the second check valve 5 faces the outside atmosphere, the other end of the second check valve 5 faces the Lava tubular cavity 3, and the second check valve 5 faces the outside atmosphere. The second check valve 5 prevents the outside air from entering the Lava tubular cavity 3 .

The plasma discharge unit includes a plate-shaped dielectric layer 7, one side of the plate-shaped dielectric layer 7 is provided with a fork-shaped AlSi ₃ O ₄ mesh exposed electrode 6, and the other side of the plate-shaped dielectric layer 7 is provided with several plate-shaped AlSi ₃ O ₄ mesh covering electrode 8; fork type AlSi ₃ O ₄ mesh exposure electrode 6 is connected to high voltage power supply, several plate type AlSi ₃ O ₄ mesh covering electrodes 8 are connected in parallel and then grounded; fork type AlSi ₃ O ₄ mesh exposure The electrode 6 faces the gas flow side, and several plate-type AlSi ₃ O ₄ mesh covering electrodes 8 are laid on the slope surface of the plasma discharge unit installation platform 2 .

The high-voltage power supply voltage is 5kV-30kV, the waveform is fast rising and slow falling, and the period is 0.1ns-1ms.

The thickness of the plate-type AlSi ₃ O ₄ mesh covering electrode 8 is 0.01mm-1mm, and the width is 5-20mm; the thickness of the fork-type AlSi ₃ O ₄ mesh-shaped exposed electrode 6 is 0.01mm-1mm, and the The width is 2-5mm.

The plate-shaped dielectric layer 7 is an F4BM material dielectric layer.

The material of the fixed plate 1 is plexiglass; the material of the plasma discharge unit mounting table 2 is polytetrafluoroethylene.

The first check valve 4 is a plate-shaped check valve with a length of 50mm, a width of 20mm and a thickness of 5mm; the second check valve 5 is a conical check valve with a taper of 15° and a height of 20mm.

The working principle of the device is as follows: when the pulsed high-voltage power supply is turned on, the fork-shaped AlSi ₃ O ₄ mesh exposed electrode 6 and the plate-shaped AlSi ₃ O ₄ mesh covered electrode 8 generate a potential difference, ionizing the air in the Lava tubular cavity 3, A particle jet along the surface of the inner cavity is generated in the Lava tubular cavity 3, and finally a confluent air flow is formed. According to Bernoulli's equation, due to the increase of the fluid velocity inside the Lava tubular cavity 3, a negative pressure is formed inside the Lava tubular cavity 3, and the air outside the Lava tubular cavity 3 is inhaled at subsonic speed. The cavity 3 contracts, and the gas is forced to accelerate to enhance the suction characteristics, as shown in Figure 6. FIG. 5 is a recording diagram of a schlieren without a pulsed high-voltage power supply, which is used for comparison and reference with FIG. 6 . And according to Figure 7, it can be seen that the maximum suction flow rate can reach 1.2m/s.

Anti-backflow design: As shown in Figure 1, when the device is inhaling, according to Bernoulli's equation, the external pressure is greater than the internal pressure of the Lava tubular cavity 3, and the external gas is tapered from the left side of the device and the second backstop The valve 5 enters the interior of the Lava tubular cavity 3. In order to prevent the airflow from being sucked in from the right outlet, a first check valve 4 is installed at the right outlet to block the entry of external airflow.

Research shows that, based on the principle of increasing the lift of the aircraft described in the background art, the key to the effect of increasing the lift is to limit the volume of the air suction device while increasing the air suction characteristics of the air suction pump. The plasma discharge unit of the device adopts a pulsed high-voltage power supply with fast rise and slow fall. The waveform is shown in Figure 8. Under the same energy consumption, the plasma discharge unit can generate a stronger particle jet, improve the internal flow speed of the cavity, and make the external The gas inhalation characteristics are increased, and the inhalation intensity can be adjusted by adjusting the power of the power supply.

As shown in FIG. 9 , the air-breathing high-lift device A based on the Laval tube-shaped plasma is vertically arranged inside the wing, and an airflow duct B is connected to the rear of the air-breathing high-lift device A based on the Lava tube-shaped plasma.

As shown in Figure 10-11, when the air suction device is not working, according to the schematic diagram of the flow field on the surface of the wing and the experimental map, it is concluded that under the condition of large angle of attack, the airflow passes through the wing, and the boundary layer of the wing is caused by the reverse pressure differential force. The air flows slower and slower, and gradually evolves into a flow separation on the surface of the wing, resulting in a complex pseudo-sequential vortex structure on the surface of the wing, which reduces the lift of the airfoil.

As shown in Figure 12-13, when the suction device starts to work, the suction device installed under the wing generates suction, sucks the airflow above the separation area, and makes the high-speed airflow attach to the surface of the wing again, resulting in a decrease in the reverse pressure gradient. , delay the flow separation of the airfoil or wing, change the leading edge vortex structure and vortex rupture, and achieve the purpose of increasing the lift of the aircraft.

Claims (7)

1. A plasma suction-type lifter based on Lava tube, characterized in that it comprises two fixed flat plates (1) arranged in parallel with each other, and two plasmas are arranged between the two fixed flat plates (1). The discharge unit mounting table (2), the longitudinal section of the plasma discharge unit mounting table (2) is a right-angled trapezoid, and the two plasma discharge unit mounting tables (2) located between the two fixed flat plates (1) are arranged in mirror symmetry , the two fixed flat plates (1) and the two plasma discharge unit mounting platforms (2) together form a Lava tubular cavity (3), the slope surfaces of the two plasma discharge unit mounting platforms (2) and the two The space enclosed by the fixed flat plate (1) constitutes the tapered section of the Lava tubular cavity (3), the opposite wall surfaces of the two plasma discharge unit installation platforms (2) and the space enclosed by the two fixed flat plates (1). The space constitutes a straight section of the Lava tubular cavity (3). Plasma discharge units are provided on the slope surfaces of the two plasma discharge unit installation platforms (2). One side of the plasma discharge units is connected to a high-voltage power supply. One side of the discharge unit is grounded; the tapered section port of the Lava tubular cavity (3) is the airflow inlet, the straight section port of the Lava tubular cavity (3) is the airflow outlet, and the airflow outlet is provided with a first check valve ( 4), the first check valve (4) prevents the outside air from entering the Lava tubular cavity (3); each plasma discharge unit installation platform (2) is provided with a second check valve (5), One end of the second check valve (5) faces the outside atmosphere, the other end of the second check valve (5) faces the Laval tubular cavity (3), and the second check valve (5) prevents the outside air from entering the Laval tubular cavity inside the cavity (3). 2 . The device for increasing the lift based on a Laval tube-shaped plasma suction type according to claim 1 , wherein the plasma discharge unit comprises a plate-shaped dielectric layer ( 7 ), a fork-shaped AlSi ₃ O ₄ mesh The exposed electrode (6) and the plate-shaped AlSi ₃ O ₄ mesh covering electrode (8), one side of the plate-shaped dielectric layer (7) is provided with a fork-shaped AlSi ₃ O ₄ mesh-shaped exposed electrode (6), and the plate-shaped dielectric layer The other side of (7) is provided with several plate-type AlSi ₃ O ₄ mesh covering electrodes (8); the fork-type AlSi ₃ O ₄ mesh-like exposed electrodes (6) are connected to a high-voltage power supply, and several plate-type AlSi ₃ O ₄ The mesh-shaped covering electrodes (8) are connected in parallel and then grounded; the fork-shaped AlSi ₃ O ₄ mesh-shaped exposed electrodes (6) face the airflow side, and several plate-shaped AlSi ₃ O ₄ mesh-shaped covering electrodes (8) are laid on the plasma discharge unit On the slope of the mounting table (2). 3. A kind of aspirating type increasing device based on Lava tubular plasma according to claim 2, characterized in that, the high voltage power supply voltage is 5kV-30kV, the waveform is a fast rising and slow falling type, and the cycle is 0.1ns -1ms. 4 . The air-inhalation type increasing lift device based on Lava tube-shaped plasma according to claim 2 , wherein the thickness of the plate-shaped AlSi ₃ O ₄ mesh covering electrode (8) is 0.01mm-1mm. 5 . , the width is 5-20mm; the thickness of the forked AlSi ₃ O ₄ mesh exposed electrode (6) is 0.01mm-1mm, and the width of each forked part is 2-5mm. 5 . The air-inhalation type increasing lift device based on a Laval tube-shaped plasma according to claim 2 , wherein the plate-shaped dielectric layer ( 7 ) is a dielectric layer of F4BM material. 6 . 6 . The plasma aspirating type increasing lift device based on Lava tube according to claim 1 , wherein the fixed plate ( 1 ) is made of plexiglass; the plasma discharge unit mounting platform ( 2 ) is 6 . The material is Teflon. 7 . The aspirating type lifter based on Lava tubular plasma according to claim 1 , wherein the first check valve ( 4 ) is a plate check valve; the second check valve ( 4 ) is a plate-shaped check valve; 7 . The check valve (5) is a conical check valve.

Images