Method and device for testing electrostatic deposition of aircraft skin materials

Abstract

The present invention discloses a method and device for testing the deposition of electrostatic materials on aircraft skins, and relates to the technical field of aviation electrostatic environment simulation. The device comprises a wind tunnel system, an environmental simulation system, and a data acquisition system; the environmental simulation system uses an ultrasonic atomizing nozzle and a polarizing needle to prepare ice crystal and water mist mixed particles, and accurately controls the particle concentration; a femtoampere meter collects the material's discharge current to the ground in real time, and combines environmental parameters such as temperature, humidity, and air pressure to analyze the linear relationship between the charging current and the particle concentration, radius, wind speed, material type, and forward projection area. This device simulates the electrostatic charging process caused by the collision and friction between the skin material and the charged particles during high-speed flight of an aircraft through ground tests, solving the problems of harsh actual flight test conditions and difficult measurements, and providing an efficient and reliable test platform for the anti-static design and environmental adaptability evaluation of aircraft skin materials, with the advantages of high simulation accuracy and repeatability.

Description

Technical Field

[0001] The present invention relates to the technical field of deposition electrostatic testing, and more particularly to a deposition electrostatic testing method and device for aircraft skin materials. Background Art

[0002] During high-speed flight, aircraft surfaces experience intense friction and collision with charged particles in the atmosphere, such as ice crystals and water droplets, leading to a rapid accumulation of electrostatic charge. This phenomenon can cause an increase in the potential of the aircraft's fuselage, potentially leading to electromagnetic interference, communication system anomalies, sensor malfunction, and even, in extreme cases, corona discharge or spark discharge, posing a serious threat to flight safety. Therefore, studying the electrostatic charging characteristics of aircraft skin materials and optimizing their antistatic properties based on this information is a critical issue that needs to be addressed in the aviation field.

[0003] Currently, research methods for static electricity deposition on aircraft are mainly divided into two categories: actual flight tests and laboratory simulation tests. Among them, actual flight tests directly measure static electricity parameters in a real flight environment. Although they can reflect actual working conditions, they have the following significant defects, such as uncontrollable environment (parameters such as particle type, concentration, temperature and humidity in the atmosphere change randomly, and it is impossible to separate the impact of a single variable on the charging current), high testing costs (frequent flights and high-precision measurement equipment are required, and it is difficult to balance economy and safety) and poor data repeatability (due to meteorological conditions, the same test conditions are difficult to reproduce, resulting in difficulties in regularity analysis).

[0004] However, the ground test equipment of laboratory simulation tests mostly adopts simplified models, simulating the collision environment through single particles (such as pure water mist), which cannot reproduce the complex charge transfer mechanism of ice crystals and water mist mixed particles; and the particle generation accuracy is insufficient, resulting in a significant deviation between the simulated environment and the actual flight conditions, which in turn leads to poor coupling of environmental parameters and the inability to comprehensively evaluate the synergistic effects of multiple factors on the charging current, which in turn affects the actual test accuracy and test results of the electrostatic test of skin material deposition. Summary of the Invention

[0005] The present invention provides a method and device for electrostatic testing of aircraft skin material deposition, aiming to solve the following problems: existing laboratory simulation devices have rough particle generation, poor coupling of environmental parameters, and single data dimension, which in turn affect the actual test accuracy and test effect of electrostatic testing of skin material deposition.

[0006] The present invention provides an aircraft skin material deposition electrostatic test device, comprising a wind tunnel system, an environmental simulation system, a high-speed camera system, and a data acquisition system. The wind tunnel system comprises a test tube, a stabilization tube, and an air duct, and the air duct is connected to a fan.

[0007] A sample fixing assembly for mounting a sample plate and adjusting the angle of the sample plate is provided inside the test tube;

[0008] The environmental simulation system is arranged in the stabilizing tube, and the environmental simulation system includes an atomizing spray component, a refrigeration component and a high-voltage polarization component, the atomizing spray component includes an ultrasonic atomizing nozzle, the refrigeration component includes a refrigeration delivery pipe, and the high-voltage polarization component includes a polarization needle;

[0009] The high-speed camera system comprises a mounting cover and a high-speed camera. The mounting cover is fixedly mounted on the outside of the test tube, and the high-speed camera is fixedly mounted inside the mounting cover. A heating component is arranged in the mounting cover.

[0010] In a preferred embodiment, a contraction tube is connected between the test tube and the stabilizing tube, a diffuser tube is connected to the end of the test tube facing away from the contraction tube, an air duct is installed at the end of the stabilizing tube facing away from the test tube, and a honeycomb rectifier is also fixedly installed in the test tube, the honeycomb rectifier being a honeycomb structure with multiple parallel channels.

[0011] In a preferred embodiment, an enclosed space is formed between the mounting cover and the outer wall of the test tube, the heating component is a fluid heating component, and the heating component includes a heat fluid input pipe and a heat fluid output pipe arranged in the mounting cover, and the heat fluid input pipe is used to input hot fluid into the mounting cover.

[0012] In a preferred embodiment, the data acquisition system includes a femtoammeter, a laser dust particle counter, a temperature and humidity sensor, an air pressure sensor, an anemometer, and a data synchronization module.

[0013] In a preferred embodiment, a transparent tube is rotatably installed in the test tube, and the transparent tube is driven to rotate by a rotary driver. The inner wall of the transparent tube is arranged in a conical structure. The front end of the transparent tube extends to the front area of ​​the sample plate, and the rear end of the transparent tube extends to the rear area of ​​the sample plate. The inner wall of the front end of the transparent tube is arranged corresponding to the inner wall of the test tube.

[0014] In a preferred embodiment, the test tube is a two-section structure, the transparent tube is docked between the two sections of the test tube, the mounting cover is fixedly connected to a docking tube, the docking tube is fixedly docked with the two sections of the test tube, the outside of the transparent tube is fixedly connected to a rotating support seat, the transparent tube is rotatably installed in the docking tube through the rotating support seat, the rotating driver is a motor, the motor is sealed and installed on the docking tube, the outside of the rotating support seat is fixedly installed with a gear ring structure, a gear is provided on the output shaft of the motor, and the motor drives the transparent tube to rotate through the cooperation of the gear and the gear ring.

[0015] In a preferred embodiment, an air suction chamber is provided at the position of the docking tube corresponding to the rear end of the transparent tube, an air suction pipe is provided on the air suction chamber, the air suction pipe is connected to the air suction pump structure, and a water suction seam is provided at the position of the test tube corresponding to the rear end of the transparent tube. The water suction seam is protruded relative to the inner wall of the rear end of the transparent tube, and the water suction seam is connected to the air suction chamber.

[0016] In a preferred embodiment, the sample fixing assembly includes a sample fixing frame and a mounting frame. The sample fixing frame is provided with a slot for placing the sample plate. The mounting frame is fixedly installed at the end of the test tube away from the stabilization tube, and the mounting frame has a forward extension structure. The sample fixing frame is installed at the forward extension end of the mounting frame through an angle adjuster. The mounting frame is used to adjust the angle of the sample fixing frame.

[0017] In a preferred embodiment, a movable cover is slidably installed at the rear of the sample fixing frame, and a guide cover is arranged around the movable cover, and the guide cover is tilted backward. A negative pressure hole is provided at the position corresponding to the sample plate in the sample fixing frame, and a piston column is fixedly connected to the position of the movable cover corresponding to the negative pressure hole, and the piston column is slidably installed in the negative pressure hole.

[0018] A method for testing electrostatic deposition of aircraft skin materials, comprising the following steps:

[0019] Step 1: Install the sample plate on the sample fixing assembly and start the fan to form airflow in the test tube;

[0020] Step 2: Start the atomizing spray assembly, the refrigeration assembly, and the high-voltage polarization assembly to form charged water mist particles and ice crystal particles in the stabilization tube, and make the charged water mist particles and ice crystal particles rush toward the surface of the sample plate according to the airflow;

[0021] Step 3: Real-time detection of the particle concentration in the test tube and use of a femtoammeter to detect the discharge current value of the sample plate to the ground;

[0022] Step 4: Monitor the surface condition of the sample plate in real time through a high-speed camera, and turn on the heating component to heat the inner area of ​​the mounting cover.

[0023] The beneficial effects of the present invention are as follows: the present invention realizes the synchronous acquisition of multi-dimensional data by using a high-precision femtoammeter, a laser particle counter and an environmental sensor, and is suitable for quantitatively analyzing the linear relationship between charging current and particle concentration, radius, wind speed, material type and forward projection area, providing a test basis for the anti-static design of aircraft skin. At the same time, during the test, by increasing the temperature inside the installation cover, the temperature of the inner wall of the test tube in this part is increased. When ice crystals contact the test tube in this area, they can melt and move directly backward with the high-speed airflow inside the test tube, thereby avoiding the formation of ice in front of the high-speed camera shooting area and hindering the visual recognition effect. At the same time, the ice crystals will gradually melt when contacting the inner wall of the test tube in this area, and will not cause impact damage to the inner wall of the test tube, thus forming effective protection for the high-speed camera shooting window. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 Schematic diagram of the overall structure of the test device of the present invention.

[0025] Figure 2 Schematic diagram of the internal structure of the test tube of the present invention.

[0026] Figure 3 It is a schematic diagram of the test state of the present invention.

[0027] Figure 4 Schematic diagram of the distribution position of the high-speed camera system of the present invention.

[0028] Figure 5 Schematic diagram of the structure of the honeycomb rectifier of the present invention.

[0029] Figure 6 Schematic diagram of the image acquisition process of the high-speed camera system of the present invention.

[0030] Figure 7 This is a schematic diagram of a test tube according to the present invention after a rotatable transparent cylinder structure is added.

[0031] Figure 8 Schematic diagram of the rotation drive mode of the transparent tube of the present invention.

[0032] Figure 9 It is a schematic diagram of the bottom structure of the docking sleeve of the present invention.

[0033] Figure 10 For the present invention Figure 9 Schematic diagram of the A part structure.

[0034] Figure 11 This is a schematic structural diagram of the improved sample fixing frame according to the present invention.

[0035] Figure 12This is a diagram showing the vacuum adsorption effect formed when wind blows toward the guide cover during the test of the present invention.

[0036] Figure 13 Schematic diagram of the structure of the polarization needle of the present invention.

[0037] Figure 14 Flow chart of the testing method of the present invention.

[0038] Figure 15 Graph showing the relationship between different particle concentrations and charging currents according to the present invention.

[0039] Figure 16 This is a curve diagram showing the relationship between different forward projection areas and charging currents according to the present invention.

[0040] Figure 17 This is a graph showing the relationship between different particle radii and charging currents according to the present invention.

[0041] In the figure: 1. Wind tunnel system; 11. Test tube; 12. Stabilizing tube; 13. Air duct; 14. Fan; 15. Contraction tube; 16. Diffuser; 17. Honeycomb rectifier; 2. Environmental simulation system; 21. Atomizing spray assembly; 211. Ultrasonic atomizing nozzle; 22. Refrigeration assembly; 221. Refrigeration delivery pipe; 23. High-voltage polarization assembly; 231. Polarization needle; 2311. Connecting end; 2312. Conductive support frame; 2313. Corona discharge needle; 3. High-speed camera system; 31. Mounting cover; 311, docking tube; 312, exhaust chamber; 313, exhaust pipe; 314, water absorption gap; 32, high-speed camera; 33, heating component; 331, heat flow input pipe; 332, heat flow output pipe; 4, sample fixing component; 41, sample fixing frame; 42, mounting frame; 43, angle adjuster; 44, movable cover; 441, guide cover; 442, piston column; 5, sample plate; 6, transparent cylinder; 61, rotating support seat; 62, rotating drive; 7, additional cooling component. DETAILED DESCRIPTION

[0042] The subject matter described herein will now be discussed with reference to exemplary embodiments. It should be understood that these embodiments are discussed solely to enable those skilled in the art to better understand and implement the subject matter described herein, and that the functions and arrangements of the elements discussed may be varied without departing from the scope of this specification. Various examples may omit, substitute, or add various processes or components as needed. In addition, features described with respect to some examples may also be combined in other examples.

[0043] Example 1, refer to the specification attached 1 to Figure 13A device for electrostatic testing of deposition of aircraft skin materials includes a wind tunnel system 1, an environmental simulation system 2, a high-speed camera system 3, and a data acquisition system. The wind tunnel system 1 includes a test tube 11, a stabilizing tube 12, and an air duct 13. The test tube 11 is a test area. A sample fixing assembly 4 for mounting a sample plate 5 and adjusting the angle of the sample plate 5 is provided inside the test tube 11. A contraction tube 15 is connected between the test tube 11 and the stabilizing tube 12. A diffuser tube 16 is connected to the end of the test tube 11 facing away from the contraction tube 15. The air duct 13 is installed at the end of the stabilizing tube 12 facing away from the test tube 11. A fan 14 is provided at the end of the air duct 13 facing away from the stabilizing tube 12.

[0044] Among them, this test device adopts a dual-fan structure, that is, the air duct 13 is connected to two groups of fans 14, and the two groups of fans 14 operate in parallel and synchronously. The airflow is combined and output through the air duct 13, with a wind speed range of 5-50m / s, and the airflow is transported to the test tube 11. The airflow is guided and transitioned through the stabilizing tube 12, and then contracted and accelerated through the contraction tube 15 to improve uniformity and reduce turbulence intensity. A honeycomb rectifier 17 is also fixedly installed in the test tube 11. The honeycomb rectifier 17 is a honeycomb structure with multiple parallel channels, which optimizes the uniformity of the airflow, so that the airflow in the test tube 11 can be evenly blown to the sample plate 5. After that, the airflow is output from the diffuser 16, and the kinetic energy of the airflow is converted into pressure energy with the help of the diffuser 16, thereby reducing energy loss.

[0045] The environmental simulation system 2 includes an atomizing spray component 21, a refrigeration component 22 and a high-voltage polarization component 23. Specifically, the atomizing spray component 21 includes an ultrasonic atomizing nozzle 211, and the ultrasonic atomizing nozzle 211 includes multiple types of atomizing nozzles (such as HT-908, HT-1008 and HT-2008, etc.). The refrigeration component 22 includes a refrigeration delivery pipe 221, and the refrigeration delivery pipe 221 is connected to a refrigeration device (using a vortex tube refrigerator, the lowest temperature is -20°C). The high-voltage polarization component 23 includes a polarization needle 231, and the polarization needle 231 is connected to a high-voltage generating device (mainly made of stainless steel). Refer to the attached manual for details. Figure 13 The polarization needle 231 consists of a connection end 2311 and a conductive support frame 2312. Multiple groups of corona discharge needles 2313 are fixedly installed on the conductive support frame 2312. The connection end 2311 is connected to a high-voltage generator, thereby applying high voltage to the multiple corona discharge needles 2313, causing them to generate corona discharge. The ultrasonic atomizing nozzle 211, the cooling delivery pipe 221, and the polarization needle 231 are all arranged in the stabilizing tube 12. The atomizing spray assembly 21 adjusts the water pressure (0.6 bar) and the air pressure (3.5 bar) so that the ultrasonic atomizing nozzle 211 generates water mist particles with a radius of 30-400 μm in the stabilizing tube 12, and the concentration can be adjusted within a range of 2×10 4 ~5×10 4 / m³. At the same time, the high-voltage polarization component 23 applies ±400kV high voltage, causing the polarization needle 231 to generate a high-voltage electric field in the stabilizing tube 12, polarizing the charge of the atomized water mist particles, making the water mist particles charged. Then, the cold air generated by the vortex tube refrigeration is injected into the stabilizing tube 12 through the refrigeration delivery pipe 221, solidifying part of the charged water mist into ice crystals, simulating the real cloud mixed particle environment.

[0046] The data acquisition system includes:

[0047] High-precision femtoammeter, a micro-current measuring instrument, model TH2690, is used to record the discharge current value of sample plate 5 to the ground during the test;

[0048] Laser dust particle counter, model NK800, used to measure the particle concentration (2.5 μm~400 μm) in the test tube 11;

[0049] Temperature and humidity sensors are used to measure the temperature and relative humidity in the wind tunnel system 1, respectively, so as to adjust the operating parameters of the atomizing spray assembly 21 and the refrigeration assembly 22, so as to maintain a relatively stable temperature and humidity environment in the test tube 11;

[0050] The air pressure sensor and anemometer are used to measure the air pressure and wind speed in the wind tunnel system 1, respectively, so as to adjust the fan 14 and maintain a relatively stable airflow effect in the test tube 11;

[0051] The data synchronization module is used to achieve multi-sensor time alignment and supports the correlation analysis between charging current and particle parameters, wind speed, and inclination angle.

[0052] It should be noted that the sample plate 5 is mainly a plate structure. Since there are many structures and materials on the aircraft, for the structural materials of the main surface of the aircraft, the sample plate 5 includes metal plates coated with aviation paint, composite materials plates and windshield material plates, and the surface is covered with insulating materials to simulate the actual skin structure of the aircraft.

[0053] In the above embodiment, in addition to using various measuring instruments to collect test parameters, a high-speed camera system 3 is also required to monitor the surface conditions of the sample plate 5 in real time and capture phenomena during the test (for example, capturing the collision process between particles and the material surface and corona discharge phenomena) to enrich the judgment conditions for the sample performance and improve the test effect. Therefore, it is necessary to ensure that an effective installation position and a clear observation range are provided for the high-speed camera system 3. Moreover, in order to avoid interference of the high-speed camera system 3 with the airflow inside the test tube 11, the high-speed camera system 3 needs to be installed on the outside of the test tube 11. Since the test tube 11 is mainly made of acrylic or other transparent materials, the high-speed camera system 3 can be directly installed on the outside of the test tube 11. If the test tube 11 is made of other high-strength non-transparent materials, a transparent window needs to be provided at the corresponding position of the test tube 11, and a transparent structure needs to be installed in the window. However, it should be noted that the transparent structure in this solution must be adapted to the shape of the test tube 11 and must not protrude into the test tube 11 to affect the airflow.

[0054] Specifically, the high-speed camera system 3 includes a mounting cover 31 and a high-speed camera 32. The mounting cover 31 is fixedly mounted on the outside of the test tube 11, and the high-speed camera 32 is fixedly mounted inside the mounting cover 31. In order to clearly observe and record the sample plate 5, this embodiment uses two sets of high-speed camera systems 3. Figure 4 The two sets of high-speed camera systems 3 are symmetrically distributed on both sides of the test tube 11. Since the high-speed camera 32 cannot be directly set on the front of the sample plate 5, in order to ensure that the recognition area of ​​the high-speed camera 32 can effectively cover the sample plate 5, the high-speed camera 32 needs to be set at an angle.

[0055] However, in the above-mentioned tests, in order to fully simulate the use environment, some test steps need to be tested in a low-temperature environment. When ice crystals follow the air flow, they are likely to impact and scratch the inner wall of the test container. In the case of long-term use, it will cause the inner wall of the container to become blurred. Especially when the number of ice crystals and water mist is increased, it is also easy to cause the inner wall of the test container to freeze, thereby affecting the image acquisition of the visual recognition camera.

[0056] In order to avoid the internal water mist and ice crystals from covering the position of the high-speed camera 32 on the inner wall of the test tube 11 during the environmental simulation test under extreme conditions, the present invention also provides the following technical solutions. Figure 4 and Figure 6, a heating component 33 is provided in the mounting cover 31. Specifically, a closed space is formed between the mounting cover 31 and the outer wall of the test tube 11. The heating component 33 is a fluid heating component, wherein the heating component 33 includes a heat flow input pipe 331 and a heat flow output pipe 332 provided in the mounting cover 31. The fluid in the fluid heating component is preferably gas, or a transparent liquid such as hot water. However, the high-speed camera 32 needs to be sealed and protected. That is, the air in the corresponding pipeline is heated by the heating device, and then transported to the heat flow input pipe 331 through the air pump. The heat flow input pipe 331 inputs hot fluid (gas) into the mounting cover 31, so that the mounting cover 31 is sealed. The temperature inside the mounting cover 31 rises, and since the test tube 11 at the corresponding high-speed camera 32 is in direct contact with the inner cavity of the mounting cover 31, the temperature of this part of the test tube 11 can be increased. When the ice crystals contact the test tube 11 in this area, they can melt and move directly backward with the high-speed airflow inside the test tube 11, thereby avoiding the formation of ice in front of the camera area of ​​the high-speed camera 32 and hindering the visual recognition effect. At the same time, the ice crystals will gradually melt when contacting the inner wall of the test tube 11 in this area, and will not cause impact damage to the inner wall of the test tube 11, thereby forming an effective protection for the camera window of the high-speed camera 32.

[0057] It should be noted that, since the high-speed camera 32 is arranged on the outside of the test tube 11, and the sample plate 5 is basically located in the center area of ​​the test tube 11, the heat radiation from the local heating at the mounting cover 31 will basically not reach the sample fixing assembly 4. Moreover, the air in the test tube 11 is always in a flowing state. Therefore, even if the local heating at the mounting cover 31 forms a certain area of ​​heat radiation inward, causing part of the air to be heated, this part of the air will immediately move backwards and will hardly affect the air temperature in the actual test area of ​​the sample plate 5. However, at the same time, if If the local heating temperature in the installation cover 31 is too high, it will also cause damage to deeper spaces. Therefore, the heating temperature in the installation cover 31 needs to be controlled. Since the main purpose of heating the installation cover 31 is to melt the ice crystals that come into contact with the inner wall of the test tube 11 in this area, the temperature in the installation cover 31 does not need to be too high. Basically, after exchanging the temperature with the inner wall of the test tube 11, the temperature of the inner wall of the test tube 11 can be made higher than 0°C. For example, when the actual test temperature in the test tube 11 is -10°C, the temperature of the installation cover 31 is preferably set to 15-40°C.

[0058] Among them, since the high-speed camera 32 and the image recognition system equipped therewith are both mature detection technologies, their specific structures and principles, as well as image acquisition and recognition, are all conventional solutions, and therefore, they will not be explained in detail in this embodiment.

[0059] Furthermore, in the above test, if it is necessary to increase the amount of water mist and ice crystals, even if the local temperature at the installation cover 31 is increased to avoid the adhesion of ice crystals to form freezing, due to the large amount of water mist, if in a low wind speed test environment, the water mist is easy to adhere to the inner wall of the test tube 11 at the shooting area of ​​the high-speed camera 32, and will also block the high-speed camera 32. Therefore, this embodiment also provides the following technical solutions, specifically, refer to the appendix of the specification. Figures 7 to 10 , a transparent tube 6 is rotatably installed in the test tube 11. Specifically, the test tube 11 is divided into two sections, and the transparent tube 6 is docked at a position between the two sections of the test tube 11. At the same time, in order to facilitate installation, a docking tube 311 is fixedly connected to the installation cover 31, and the docking tube 311 is fixedly docked with the two sections of the test tube 11 to form an integral structure, and the outside of the transparent tube 6 is fixedly connected to a rotating support seat 61. The transparent tube 6 is rotatably installed in the docking tube 311 through the rotating support seat 61. The docking tube 311 is provided with a rotating driver 62 for driving the transparent tube 6 to rotate. The inner wall of the transparent tube 6 is a conical structure with a smaller taper, and the sample plate 5 is located in the area of ​​the transparent tube 6, that is, the front end of the transparent tube 6 (that is, the end close to the stabilizing tube 12) extends to the front area of ​​the sample plate 5, and the rear end of the transparent tube 6 (i.e., the end away from the stabilizing tube 12) extends to the rear area of ​​the sample plate 5, and the front inner wall of the transparent tube 6 is set corresponding to the inner wall of the test tube 11, that is, the diameter of the front inner wall of the transparent tube 6 is the same as the diameter of the inner wall of the test tube 11, and the inner wall of the transparent tube 6 is a conical structure as a whole. Therefore, the inner wall diameter of the rear end of the transparent tube 6 is increased. During the actual test, the transparent tube 6 can be driven to rotate at a high speed so that the water mist and other water bodies attached to the inner wall of the transparent tube 6 have a certain centrifugal force. However, since the centrifugal force is outward and the transparent tube 6 blocks the water body, although the water body cannot be thrown out directly, the above-mentioned centrifugal force causes the water body to form a backward component force on the conical structure of the transparent tube 6, and then cooperates with the airflow in the test tube 11 itself to accelerate the flow of water mist to the rear to avoid blocking the high-speed camera 32.

[0060] It should be noted that since the inner wall of the transparent tube 6 is set to a conical structure, it will have a certain impact on the airflow in this area. However, the sample plate 5 is relatively far away from the side wall of the test tube 11, and the impact of the airflow here will hardly affect the actual detection of the sample plate 5. Moreover, the gradual change of the conical structure of the transparent tube 6 makes the impact on the nearby airflow concentrated on the rear end position of the transparent tube 6, and the rear end area is located behind the sample plate 5. That is, although the airflow forms an irregular disturbance when it reaches this place, the disturbance area has left the test area of ​​the sample plate 5 and will not affect the airflow in front of the sample plate 5 as a whole. As for the rotation drive of the transparent tube 6, a simple motor drive can be used. For example, the rotation driver 62 uses a motor, and the motor is sealed and installed on the docking tube 311, and a gear ring structure is fixedly installed on the outside of the rotating support seat 61. By means of the gear on the motor shaft engaging with it, the transparent tube 6 can be driven to rotate by the motor.

[0061] Furthermore, in order to control the water body flowing backward in the transparent tube 6, this embodiment also provides the following technical solutions. Figure 7 、 9 and 10, an air suction chamber 312 is provided at the position of the docking tube 311 corresponding to the rear end of the transparent tube 6, an air suction pipe 313 is provided on the air suction chamber 312, the air suction pipe 313 is connected to the air suction pump structure, and a water suction seam 314 is provided at the position of the rear end of the transparent tube 6 of the test tube 11, the water suction seam 314 is protruded relative to the inner wall of the rear end of the transparent tube 6, and the water suction seam 314 is connected to the air suction chamber 312. In addition, a water suction structure can be provided on the pipeline between the air suction pipe 313 and the air suction pump.

[0062] It should be noted that when the transparent tube 6 rotates, the water on its surface is accelerated to move backward. At the same time, the vacuum chamber 312 forms an adsorption negative pressure under the action of the vacuum pump, which helps to increase the flow rate of the gas on the inner wall surface of the transparent tube 6. At the same time, it can also accelerate the water to enter the vacuum chamber 312 from the water absorption gap 314 and finally be extracted. Since the water absorption gap 314 is located behind the sample plate 5, the air flow changes here will not affect the test of the sample plate 5.

[0063] Furthermore, in order to fully study the effect of the airflow angle, i.e. the airflow and the forward projection area of ​​the sample plate 5 on the charging current, it is necessary to test the sample plate 5 at different angles. Therefore, the sample fixing assembly 4 needs to have an angle adjustment function. For details, please refer to the attached manual. Figure 4The sample fixing assembly 4 includes a sample fixing frame 41 and a mounting frame 42. The sample fixing frame 41 is provided with a slot for placing the sample plate 5. The mounting frame 42 is fixedly installed at the end of the test tube 11 away from the stabilizing tube 12, and the mounting frame 42 has a forward extension structure. The sample fixing frame 41 is installed at the forward extension end of the mounting frame 42 through an angle adjuster 43. The mounting frame 42 is used to adjust the angle of the sample fixing frame 41. The mounting frame 42 can adopt a simple rotation structure and be equipped with a corresponding locking structure. After manually adjusting the angle of the sample fixing frame 41, it is locked. It can also adopt an automatic rotation drive structure to effectively adjust the angle of the sample plate 5.

[0064] In addition, in order to ensure that the sample plate 5 can be relatively stably installed in the sample holder 41, the card slot of the sample holder 41 needs to be relatively tight with the sample plate 5. However, due to the temperature drop during the subsequent test, the difference in cold shrinkage of the two materials will cause some looseness. Therefore, this embodiment also provides the following technical solutions. For details, refer to the attached manual. Figure 11 and Figure 12 A movable cover 44 is slidably installed at the rear of the sample fixing frame 41, and a guide cover 441 is arranged around the movable cover 44. The guide cover 441 is tilted backward. A negative pressure hole is provided at the position corresponding to the sample plate 5 in the sample fixing frame 41. A piston column 442 is fixedly connected to the position of the movable cover 44 corresponding to the negative pressure hole, and the piston column 442 is slidably installed in the negative pressure hole.

[0065] During actual use, affected by the airflow of the test tube 11, the guide cover 441 and the movable cover 44 will be blown backward, thereby causing the piston column 442 to move backward, forming a negative pressure in the negative pressure hole of the sample fixing frame 41, thereby improving the adsorption effect on the sample plate 5. At the same time, the guide cover 441 can also gradually guide the airflow backward to avoid airflow disturbance around the sample plate 5.

[0066] In addition, since the above-mentioned solution of the present invention adopts an instant heating solution for the mounting cover 31, in order to further avoid the influence of heat radiation on the temperature around the sample plate 5, a temperature sensor can be set around the sample fixing frame 41, and an additional cooling component 7 can be set around the movable cover 44. The additional cooling component 7 can adopt a cold air circulation pipe structure. If the temperature around the sample fixing frame 41 is affected by the temperature and causes the temperature to rise, cold air can be introduced into the additional cooling component 7 to further cool the gas around the sample plate 5.

[0067] Referring to Appendix 14 of the specification, based on the above-mentioned test device, the present invention also provides an aircraft skin material deposition electrostatic test method, comprising the following steps:

[0068] Step 1: Install the sample plate 5 on the sample fixing assembly 4 and start the fan 14 to form airflow in the test tube 11;

[0069] Step 2: Start the atomizing spray assembly 21, the cooling assembly 22, and the high-voltage polarization assembly 23 to form charged water mist particles and ice crystal particles in the stabilizing tube 12, and make the charged water mist particles and ice crystal particles rush toward the surface of the sample plate 5 according to the airflow;

[0070] Step 3: Real-time detection of the particle concentration in the test tube 11 and detection of the discharge current value of the sample plate 5 to the ground using a femtoammeter;

[0071] Step 4: Monitor the surface condition of the sample plate 5 in real time through the high-speed camera 32 , and turn on the heating component 33 to heat the inner area of ​​the mounting cover 31 .

[0072] Based on the above test method, in order to analyze the relationship between charging current and particle concentration, this embodiment makes the following test configuration:

[0073] The ultrasonic atomizing nozzle 211 uses the HT-908 two-fluid ultrasonic atomizer, adjusts the water pressure to 0.6 bar and the air pressure to 3.5 bar, and generates water mist particles with a radius of 30-35 μm. The refrigeration delivery pipe 221 inputs -10℃ cold air to solidify 30% of the water mist into ice crystals.

[0074] Apply +200 kV voltage to the polarization needle 231 to make the particles positively charged;

[0075] The wind speed in the test tube 11 is fixed at 50 m / s, the temperature is 25°C, the humidity is 50%, and the air pressure is 1013 hPa;

[0076] Sample plate 5 is a metal plate (side length 300 mm) coated with ordinary aviation topcoat, with an inclination angle of 90°.

[0077] It should be noted that the atomizing spray assembly 21 and the refrigeration assembly 22 generate ice crystal-water mist mixed particles, and the concentration is set to 2×10 4 , 3×10 4 , 4×10 4 , 5×10 4 The laser dust particle counter monitors the particle concentration in real time, the femtoammeter records the discharge current value of the sample board 5, the intelligent anemometer calibrates the wind speed fluctuation to ±2m / s, and the data acquisition system synchronously stores the current, concentration, temperature and humidity, and wind speed data.

[0078] The test results are as follows:

[0079] The charging current increases linearly with the increase of particle concentration (e.g. 2×10 4 15.97nA for 5×10 4 34.30nA when the test data is as shown in the appendix of the manual. Figure 15As shown in the figure, the experimental data verified the mechanism by which high concentrations of charged particles intensify static electricity accumulation, providing a basis for risk assessment of aircraft passing through thunderstorm clouds.

[0080] Example 2: To simulate and verify the effect of the forward projected area on the charging current, this example makes the following configuration for the experiment:

[0081] The wind speed in the test tube 11 is fixed at 50 m / s, the particle radius is 200 μm, and the concentration is 2×10 4 pieces / m³;

[0082] Adjust the inclination angle of the sample holder 41 (to 45°, 60°, 75°, and 90°, respectively), corresponding to a forward projection area of ​​0.05 m² to 0.071 m²;

[0083] Sample plate 5 is a metal plate coated with ordinary aviation topcoat.

[0084] It should be noted that each time the inclination angle of the sample holder 41 is adjusted, the device needs to be restarted once, and the femtoammeter records the charging current value of the sample board 5 in a stable state. The test is repeated three times to obtain the average value.

[0085] The test results are as follows:

[0086] The charging current increases significantly with the increase of projected area. The charging current is 412.81nA at 0.05m2 and 612.55nA at 0.071m2. The test data of this group are shown in the attached manual. Figure 16 As shown in Figure 3, the data proves the impact of aircraft attitude changes on electrostatic charging current, providing a basis for heading optimization design.

[0087] Example 3: To analyze the relationship between charging current and particle radius, the following configuration is made for the experiment in this example:

[0088] The ultrasonic atomizing nozzle 211 uses the atomizers of HT-908, HT-1008 and HT-2008 nozzles in turn to generate particles with a radius of 35~200μm and a particle concentration of 2×10 4 pieces / m³;

[0089] Sample plate 5 is a metal plate coated with ordinary aviation topcoat;

[0090] The wind speed in the test tube 11 is 50±3 m / s, and the sample fixing frame 41 has an inclination angle of 90°.

[0091] It should be noted that after the sample plate 5 is fixed, the ultrasonic atomizing nozzle 211 with different nozzles is adjusted in sequence to generate particles with a radius of 35-200 μm, and then other equipment is used to record the discharge current value of each material.

[0092] The test results are as follows:

[0093] When the particle radius is 30μm, the charging current is 13.96nA, and when the particle diameter is 200μm, the charging current is 530.14nA. This set of test data is shown in the attached manual. Figure 17 As shown, the results show that when the tested material is fixed, the higher the particle radius, the greater the charging current.

[0094] In summary, this invention integrates an ultrasonic atomizer (such as the HT-908 and HT-2008 series) with polarized tip technology to generate ice crystal-water mist mixed charged particles, precisely controlling their radius, concentration, and charge distribution. A modular air blowing system (i.e., wind tunnel system 1, with a wind speed of 50 m / s) is used to simulate high-speed flight environments, combined with an adjustable inclination test platform to reproduce different forward projected areas. Furthermore, a high-precision femtoammeter, laser particle counter, and environmental sensors enable simultaneous multi-dimensional data acquisition, enabling quantitative analysis of the linear relationship between charge current and particle concentration, radius, wind speed, material type, and forward projected area, providing an experimental basis for anti-static design of aircraft skins. This approach overcomes the bottlenecks of conventional methods, such as coarse particle generation, poor variable coupling, and single data dimension, providing a reliable platform for quantitatively analyzing the correlation between charge current and particle parameters, material type, and flight attitude, significantly improving experimental efficiency and providing engineering guidance.

[0095] The above describes the embodiments of this embodiment, but this embodiment is not limited to the above specific implementation methods. The above specific implementation methods are merely illustrative and not restrictive. Ordinary technicians in this field can also make many forms based on the inspiration of this embodiment, all of which are protected by this embodiment.

Claims

1. An aircraft skin material deposition electrostatic test device, characterized by: The invention comprises a wind tunnel system (1), an environmental simulation system (2), a high-speed camera system (3) and a data acquisition system, wherein the wind tunnel system (1) comprises a test tube (11), a stabilization tube (12) and an air duct (13), and the air duct (13) is connected to a fan (14); The interior of the test tube (11) is provided with a sample fixing assembly (4) for mounting a sample plate (5) and adjusting the angle of the sample plate (5); The environmental simulation system (2) is arranged in the stabilizing tube (12), and the environmental simulation system (2) includes an atomizing spray assembly (21), a refrigeration assembly (22), and a high-voltage polarization assembly (23), wherein the atomizing spray assembly (21) includes an ultrasonic atomizing nozzle (211), the refrigeration assembly (22) includes a refrigeration delivery pipe (221), and the high-voltage polarization assembly (23) includes a polarization needle (231); The high-speed camera system (3) comprises a mounting cover (31) and a high-speed camera (32), wherein the mounting cover (31) is fixedly mounted on the outside of the test tube (11), and the high-speed camera (32) is fixedly mounted inside the mounting cover (31), and a heating component (33) is provided in the mounting cover (31); A transparent cylinder (6) is rotatably mounted in the test tube (11), and the transparent cylinder (6) is driven to rotate by a rotation driver (62). The inner wall of the transparent cylinder (6) is arranged in a conical structure. The front end of the transparent cylinder (6) extends to the front area of ​​the sample plate (5), and the rear end of the transparent cylinder (6) extends to the rear area of ​​the sample plate (5). The inner wall of the front end of the transparent cylinder (6) is arranged corresponding to the inner wall of the test tube (11); The test tube (11) is a two-section structure, the transparent tube (6) is docked between the two sections of the test tube (11), the mounting cover (31) is fixedly connected to a docking tube (311), the docking tube (311) is fixedly docked with the two sections of the test tube (11), the outside of the transparent tube (6) is fixedly connected to a rotating support seat (61), the transparent tube (6) is rotatably mounted in the docking tube (311) through the rotating support seat (61), the rotating driver (62) is a motor, the motor is sealed and mounted on the docking tube (311), the outside of the rotating support seat (61) is fixedly mounted with a gear ring structure, the output shaft of the motor is provided with a gear, and the motor drives the transparent tube (6) to rotate through the cooperation of the gear and the gear ring; An air extraction chamber (312) is provided at a position of the docking tube (311) corresponding to the rear end of the transparent tube (6), an air extraction pipe (313) is provided on the air extraction chamber (312), and the air extraction pipe (313) is connected to an air extraction pump structure. A water absorption slit (314) is provided at a position of the test tube (11) corresponding to the rear end of the transparent tube (6), and the water absorption slit (314) is protruded relative to the inner wall of the rear end of the transparent tube (6), and the water absorption slit (314) is communicated with the air extraction chamber (312).

2. The aircraft skin material deposition electrostatic test device according to claim 1, characterized in that: A contraction tube (15) is connected between the test tube (11) and the stabilization tube (12); an end of the test tube (11) facing away from the contraction tube (15) is connected to a diffusion tube (16); the air duct (13) is installed at the end of the stabilization tube (12) facing away from the test tube (11); a honeycomb rectifier (17) is also fixedly installed in the test tube (11); the honeycomb rectifier (17) is a honeycomb structure with multiple parallel channels.

3. The aircraft skin material deposition electrostatic test device according to claim 2, characterized in that: A closed space is formed between the mounting cover (31) and the outer wall of the test tube (11). The heating component (33) is a fluid heating component. The heating component (33) includes a heat flow input pipe (331) and a heat flow output pipe (332) arranged in the mounting cover (31). The heat flow input pipe (331) is used to input hot fluid into the mounting cover (31).

4. The aircraft skin material deposition electrostatic test device according to claim 3, characterized in that: The data acquisition system includes a femtoammeter, a laser dust particle counter, a temperature and humidity sensor, an air pressure sensor, an anemometer and a data synchronization module.

5. The aircraft skin material deposition electrostatic test device according to claim 4, characterized in that: The sample fixing assembly (4) comprises a sample fixing frame (41) and a mounting frame (42), wherein the sample fixing frame (41) is provided with a slot for placing a sample plate (5), and the mounting frame (42) is fixedly mounted on an end of the test tube (11) away from the stabilizing tube (12), and the mounting frame (42) has a forward extension structure, and the sample fixing frame (41) is mounted at the forward extension end of the mounting frame (42) via an angle adjuster (43), and the mounting frame (42) is used to adjust the angle of the sample fixing frame (41).

6. The aircraft skin material deposition electrostatic test device according to claim 5, characterized in that: A movable cover (44) is slidably mounted at the rear of the sample fixing frame (41), and a guide cover (441) is arranged around the movable cover (44), and the guide cover (441) is tilted backward. A negative pressure hole is provided at a position corresponding to the sample plate (5) in the sample fixing frame (41), and a piston column (442) is fixedly connected to the position of the movable cover (44) corresponding to the negative pressure hole, and the piston column (442) is slidably mounted in the negative pressure hole.

7. A method for testing electrostatic deposition of aircraft skin materials, characterized in that: The test device according to claim 6 is used to carry out the test, comprising the following steps: Step 1: Install the sample plate (5) on the sample fixing assembly (4), start the fan (14), and form an air flow in the test tube (11); Step 2: Start the atomizing spray assembly (21), the refrigeration assembly (22), and the high-voltage polarization assembly (23) to form charged water mist particles and ice crystal particles in the stabilizing tube (12), and make the charged water mist particles and ice crystal particles rush toward the surface of the sample plate (5) according to the airflow; Step 3: Real-time detection of the particle concentration in the test tube (11), and use of a femtoammeter to detect the discharge current value of the sample plate (5) to the ground; Step 4: Monitor the surface condition of the sample plate (5) in real time through a high-speed camera (32), and turn on the heating component (33) to heat the inner area of ​​the mounting cover (31).

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