Aircraft skin material deposition static test method and device

Abstract

The invention discloses an aircraft skin material deposition static test method and device, and relates to the technical field of aviation static environment simulation. The device comprises a wind tunnel system, an environment simulation system and a data acquisition system. The environment simulation system prepares ice crystal and water mist mixed particles through an ultrasonic atomization nozzle and a polarization needle, and the particle concentration is accurately controlled. A flying ammeter collects a material-to-ground discharge current value in real time, and in combination with environmental parameters such as temperature and humidity, air pressure and the like, linear relations between a charging current and particle concentration, radius, wind speed, material type and forward projection area are analyzed. The device simulates an electrostatic charging process of collision and friction between a skin material and charged particles during high-speed flight of an aircraft through a ground test, solves the problems of harsh actual flight test conditions and difficult measurement, and provides an efficient and reliable test platform for antistatic design and environmental adaptability evaluation of the skin material of the aircraft. The method has the advantages of high simulation precision and repeatability.

Description

Technical Field

[0001] The present invention relates to the technical field of deposition electrostatic test, and more specifically, to a method and device for depositing electrostatic test on the skin material of an aircraft. Background Art

[0002] During the high-speed flight of an aircraft, its surface rubs and collides violently with charged particles such as ice crystals and water droplets in the atmosphere, resulting in the rapid accumulation of static charges. This phenomenon will cause the body potential to rise, which may cause problems such as electromagnetic interference, abnormal communication systems, and malfunction of sensors. In extreme cases, it may even cause corona discharge or spark discharge, seriously threatening flight safety. Therefore, studying the electrostatic charging characteristics of aircraft skin materials and optimizing the antistatic performance of materials based on this is a key issue that urgently needs to be solved in the aviation field.

[0003] At present, the research methods for aircraft deposition static electricity are mainly divided into two categories: actual flight tests and laboratory simulation tests. Among them, the actual flight test directly measures static electricity parameters in a real flight environment. Although it can reflect the actual working conditions, it has the following significant defects, such as uncontrollable environment (parameters such as the types, concentrations, temperature, and humidity of particles in the atmosphere change randomly, and it is impossible to separate the influence of a single variable on the charging current), high test costs (frequent flights and high-precision measurement equipment need to be carried, and it is difficult to balance economy and safety), and poor data repeatability (restricted by meteorological conditions, it is difficult to reproduce the same test conditions, resulting in difficulties in regular analysis), etc.

[0004] The ground test devices for laboratory simulation tests mostly use simplified models, and simulate the collision environment through a single particle (such as pure water mist), which cannot reproduce the complex charge transfer mechanism of ice crystal and water mist mixed particles; and the particle generation accuracy is insufficient, resulting in a significant deviation between the simulated environment and the real flight conditions, and then leading to poor coupling of environmental parameters, unable to comprehensively evaluate the synergistic influence of multiple factors on the charging current, and further affecting the actual test accuracy and test effect of the deposition static electricity test on the skin material. Summary of the Invention

[0005] A method and device for depositing electrostatic test on the skin material of an aircraft provided by the present invention aims to solve the problems that the particle generation of existing laboratory simulation devices is rough, the coupling of environmental parameters is poor, and the data dimension is single, thereby affecting the actual test accuracy and test effect of the deposition static electricity test on the skin material.

[0006] The present invention provides a device for depositing electrostatic test on the skin material of an aircraft, including a wind tunnel system, an environment simulation system, a high-speed camera system, and a data acquisition system. The wind tunnel system includes a test tube, a stabilizing 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 extraction chamber is provided at a position corresponding to the rear end of the transparent cylinder of the docking cylinder. An air extraction pipe is provided on the air extraction chamber, and the air extraction pipe is connected to an air extraction pump structure. A water absorption slit is provided at a position corresponding to the rear end of the transparent cylinder of the test tube. The water absorption slit protrudes relative to the inner wall of the rear end of the transparent cylinder, and the water absorption slit communicates with the air extraction chamber.

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

[0017] In a preferred embodiment, a movable cover is slidably installed behind the specimen fixing frame. Guide covers are provided around the movable cover, and the guide covers are inclined backward. Negative pressure holes are provided in the specimen fixing frame at positions corresponding to the test sample plate. A piston column is fixedly connected to the movable cover at a position corresponding to the negative pressure holes, and the piston column is slidably installed in the negative pressure holes.

[0018] A method for depositing static electricity on an aircraft skin material for testing includes the following steps:

[0019] Step 1: Install the test sample plate on the specimen fixing assembly, start the fan, and form an air flow 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 and ice crystal particles in the stabilizing tube, and make the above-mentioned charged particles rush towards the surface of the test sample plate according to the air flow;

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

[0022] Step 4: Real-time monitor the surface condition of the test sample plate through a high-speed camera, and turn on the heating assembly to heat the inner area of the mounting cover.

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

[0024] Figure 1 It is a schematic diagram of the overall structure of the test device of the present invention.

[0025] Figure 2 It is a 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 It is a schematic diagram of the distribution position of the high-speed imaging system of the present invention.

[0028] Figure 5 It is a schematic diagram of the structure of the honeycomb rectifier of the present invention.

[0029] Figure 6 It is a schematic diagram of the image acquisition process of the high-speed imaging system of the present invention.

[0030] Figure 7 It is a schematic diagram after adding a rotatable transparent cylinder structure inside the test tube of the present invention.

[0031] Figure 8 It is a schematic diagram of the rotation driving method of the transparent cylinder of the present invention.

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

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

[0034] Figure 11 It is a schematic diagram of the structure after improving the sample fixing rack of the present invention.

[0035] Figure 12This is the vacuum adsorption effect diagram formed when the wind blows towards the guiding cover during the experiment of the present invention.

[0036] Figure 13 This is the structural schematic diagram of the polarization needle of the present invention.

[0037] Figure 14 This is the flowchart of the test method of the present invention.

[0038] Figure 15 This is the relationship curve diagram between different particle concentrations and charging currents of the present invention.

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

[0040] Figure 17 This is the relationship curve diagram between different particle radii and charging currents of 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 tube; 17. Honeycomb rectifier; 2. Environment 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. Connection end; 2312. Conductive support frame; 2313. Corona discharge needle; 3. High-speed camera system; 31. Installation cover; 311. Docking cylinder; 312. Air extraction chamber; 313. Air extraction pipe; 314. Water absorption slit; 32. High-speed camera; 33. Heating assembly; 331. Heat flow input pipe; 332. Heat flow output pipe; 4. Specimen fixing assembly; 41. Specimen fixing frame; 42. Installation frame; 43. Angle adjuster; 44. Movable cover; 441. Guiding cover; 442. Piston column; 5. Specimen plate; 6. Transparent cylinder; 61. Rotating support seat; 62. Rotating drive; 7. Additional cooling assembly. Detailed implementation manners

[0042] Now, the subject matter described herein will be discussed with reference to exemplary embodiments. It should be understood that discussing these embodiments is only to enable those skilled in the art to better understand and thus implement the subject matter described herein. Without departing from the scope of protection of the content of this specification, changes can be made to the functions and arrangements of the elements discussed. Each example can omit, substitute, or add various processes or components as needed. Additionally, the features described relative to some examples can also be combined in other examples.

[0043] Example 1. Refer to Appendix 1 of the specification 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 4per cubic meter. At the same time, the high-voltage polarization component 23 applies a high voltage of ±400 kV, causing a high-voltage electric field to occur in the stabilization tube 12 by the polarization needles 231, charge-polarizing the atomized water mist particles to make them charged, and then injecting the cold air formed by vortex tube refrigeration into the stabilization tube 12 through the refrigeration delivery pipe 221, solidifying some of the charged water mist into ice crystals to simulate the real cloud mixed particle environment.

[0046] The data acquisition system includes:

[0047] A high-precision femtoammeter, a microcurrent measuring instrument with the model TH2690, used to record the discharge current value of the test sample plate 5 to the ground during the test;

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

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

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

[0051] A data synchronization module, used to achieve time alignment of multiple sensors and support the correlation analysis of charging current with particle parameters, wind speed, and inclination angle.

[0052] It should be noted that the test sample plate 5 is mainly of a plate structure. Among them, because there are many structures and materials on the aircraft, therefore, for the main external structural materials of the aircraft, the test sample plate 5 includes metal plates, composite material plates, and windshield glass material plates coated with aviation topcoat, and an insulating material is covered on its surface to simulate the actual skin structure of the aircraft.

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

[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 installed outside the test tube 11, and the high-speed camera 32 is fixedly installed inside the mounting cover 31. Among them, in order to clearly observe and record the test sample plate 5, two groups of high-speed camera systems 3 are used in this embodiment. Refer to the attached Figure 4 description. The two groups 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 in front of the test sample plate 5, in order to ensure that the recognition area of the high-speed camera 32 can effectively cover the test sample plate 5, the high-speed camera 32 needs to be inclined.

[0055] However, in the above tests, in order to fully simulate the use environment, some test steps need to be tested in a low-temperature environment. When ice crystals flow with 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 vision recognition camera.

[0056] In order to avoid the covering effect of the internal water mist and ice crystals on the position of the inner wall of the test tube 11 corresponding to the high-speed camera 32 during the environmental simulation test under extreme conditions, the present invention also provides the following technical solutions. Specifically, refer to the attached Figure 4 description Figure 6, a heating component 33 is provided in the installation cover 31. Specifically, a sealed space is formed between the installation cover 31 and the outer wall of the test tube 11. The heating component 33 is a fluid heating component. Among them, the heating component 33 includes a heat flow input pipe 331 and a heat flow output pipe 332 provided in the installation cover 31. The fluid in the fluid heating component is preferably gas, and can also be a transparent liquid such as hot water, but the high-speed camera 32 needs to be well sealed and protected. That is, the air in the corresponding pipe is heated by a heating device, and then conveyed to the heat flow input pipe 331 through an air pump. The hot fluid (gas) is input into the installation cover 31 from the heat flow input pipe 331, so that the temperature inside the installation cover 31 rises. Since the test tube 11 corresponding to the high-speed camera 32 is directly in contact with the inner cavity of the installation cover 31, the temperature of this part of the test tube 11 can be increased. When the ice crystal contacts the test tube 11 in this area, it can melt and move directly backward along with the high-speed airflow inside the test tube 11, thus avoiding the formation of ice on the front of the imaging area of the high-speed camera 32 and hindering the visual recognition effect. At the same time, the ice crystal will gradually melt when it contacts 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, forming an effective protection for the imaging window of the high-speed camera 32.

[0057] It should be noted that since the high-speed camera 32 is provided outside the test tube 11, and the test sample plate 5 is basically located in the central area of the test tube 11, for the local heating at the installation cover 31, its heat radiation basically will not reach the sample fixing component 4. Moreover, the air in the test tube 11 is always in a flowing state. Therefore, for the local heating at the installation cover 31, even if a certain area of heat radiation is formed inward and part of the air is heated, this part of the air will move backward immediately and hardly affect the air temperature in the actual test area of the test sample plate 5. However, at the same time, if the local heating temperature in the installation cover 31 is too high, it will also cause damage to a deeper space. Therefore, it is necessary to control the heating temperature in the installation cover 31. Since the main purpose of heating the installation cover 31 is to melt the ice crystals contacting 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 with the temperature of the inner wall of the test tube 11, it can make the temperature of the inner wall of the test tube 11 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 its equipped image recognition system are both mature detection technologies, their specific structures and principles, as well as the acquisition and recognition of images, are all conventional solutions. Therefore, this embodiment will not be explained in too much detail.

[0059] Further, in the above test, if it is necessary to increase the quantity of water mist and ice crystals, even if the local temperature at the installation cover 31 is increased to avoid ice crystal attachment and freezing, due to the large amount of water mist, if in a low wind speed test environment, the water mist is likely to attach to the inner wall of the test tube 11 in the imaging area of the high-speed camera 32, which will also block the high-speed camera 32. Therefore, the present embodiment also provides the following technical solution. Specifically, refer to the appended Figures 7 to 10 , a transparent cylinder 6 is rotatably installed in the test tube 11. Specifically, the test tube 11 is divided into two sections, and the transparent cylinder 6 is butted at the position between the two sections of the test tube 11. At the same time, for the convenience of installation, a butting cylinder 311 is fixedly connected to the installation cover 31, and the butting cylinder 311 is fixedly butted with the two sections of the test tube 11 to form an integral structure. A rotating support seat 61 is fixedly connected to the outside of the transparent cylinder 6, and the transparent cylinder 6 is rotatably installed in the butting cylinder 311 through the rotating support seat 61. A rotating driver 62 for driving the transparent cylinder 6 to rotate is arranged on the butting cylinder 311. The inner wall of the transparent cylinder 6 is a conical surface structure with a small taper. The test sample plate 5 is located within the area of the transparent cylinder 6, that is, the front end of the transparent cylinder 6 (i.e., the end close to the stabilizing tube 12) extends to the front area of the test sample plate 5, and the rear end of the transparent cylinder 6 (i.e., the end far from the stabilizing tube 12) extends to the rear area of the test sample plate 5. The inner wall of the front end of the transparent cylinder 6 is correspondingly arranged with the inner wall of the test tube 11, that is, the inner wall diameter of the front end of the transparent cylinder 6 is the same as the inner wall diameter of the test tube 11, and the inner wall of the transparent cylinder 6 is a conical surface structure as a whole. Therefore, the inner wall diameter of the rear end of the transparent cylinder 6 is increased. During the actual test, the transparent cylinder 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 cylinder 6 have a certain centrifugal force. However, since the centrifugal force is outward and the transparent cylinder 6 blocks the water body, although the water body cannot be directly thrown outwards, the above centrifugal force causes the water body to have a backward component force on the conical surface structure of the transparent cylinder 6, thereby cooperating with the airflow inside the test tube 11 to accelerate the water mist to flow backward and avoid blocking the high-speed camera 32.

[0060] It should be noted that since the inner wall of the transparent cylinder 6 is arranged in a conical structure, it will have a certain impact on the air flow in this area. However, the distance between the test sample plate 5 and the side wall of the test tube 11 is relatively far, and the influence of the air flow here hardly affects the actual detection of the test sample plate 5. Moreover, the gradual change of the conical structure of the transparent cylinder 6 makes the influence on the nearby air flow concentrated at the rear end position of the transparent cylinder 6, and this rear end area is located behind the test sample plate 5. That is, although irregular disturbances are formed when the air flow reaches this place, the disturbed area has left the test area of the test sample plate 5, and overall it will not affect the air flow effect in front of the test sample plate 5. For the rotational drive of the transparent cylinder 6, a motor drive can be simply adopted. For example, the rotational drive 62 uses a motor, which is enclosed and installed on the docking cylinder 311, and a toothed ring structure is fixedly installed outside the rotational support base 61. By meshing the gear on the motor shaft with it, the transparent cylinder 6 can be rotated by the motor.

[0061] Furthermore, in order to deal with the water body flowing backward in the transparent cylinder 6, the present embodiment also provides the following technical solution. Specifically, referring to the attached drawings of the specification Figure 7 、 9 and 10, an air extraction chamber 312 is provided at the position of the docking cylinder 311 corresponding to the rear end of the transparent cylinder 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 the position of the test tube 11 corresponding to the rear end of the transparent cylinder 6. The water absorption slit 314 protrudes relative to the inner wall of the rear end of the transparent cylinder 6, and the water absorption slit 314 is communicated with the air extraction chamber 312. In addition, a water absorption structure can be provided on the pipeline between the air extraction pipe 313 and the air extraction pump.

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

[0063] Furthermore, during the test, in order to fully study the influence of the angle of the air flow, that is, the air flow and the forward projection area of the test sample plate 5 on the charging current, it is necessary to test the test sample plate 5 at different angles. Therefore, the sample fixing assembly 4 needs to have an angle adjustment function. Specifically, referring to the attached drawings of the specification Figure 4, the sample fixing assembly 4 includes a sample fixing frame 41 and a mounting frame 42. A slot for placing the sample plate 5 is provided in the sample fixing frame 41. The mounting frame 42 is fixedly installed at one end of the test tube 11 away from the stabilizing tube 12, and the mounting frame 42 has a forward extending structure. The sample fixing frame 41 is installed at the forward extending 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. Among them, the mounting frame 42 can adopt a simple rotating 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 rotating drive structure, so as to effectively adjust the angle of the sample plate 5.

[0064] In addition, in order to enable the sample plate 5 to be relatively stably installed in the sample fixing frame 41, the slot of the sample fixing frame 41 needs to be relatively tight with the sample plate 5. However, during the subsequent test process, the temperature will decrease, and due to the cold shrinkage difference between the two materials, a certain looseness will be caused. For this reason, the present embodiment also provides the following technical solutions. Specifically, refer to the attached Figure 11 and Figure 12 , a movable cover 44 is slidably installed behind the sample fixing frame 41. Guide covers 441 are arranged around the movable cover 44, and the guide covers 441 are inclined backward. Negative pressure holes are provided at the position of the sample fixing frame 41 corresponding to the sample plate 5. A piston column 442 is fixedly connected at the position of the movable cover 44 corresponding to the negative pressure holes, and the piston column 442 is slidably installed in the negative pressure holes.

[0065] During actual use, affected by the airflow in the test tube 11, the guide cover 441 will drive the movable cover 44 backward, thereby causing the piston column 442 to move backward, forming negative pressure in the negative pressure holes of the sample fixing frame 41, 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 instant heating scheme for the mounting cover 31 is adopted in the above scheme of the present invention, in order to further avoid the influence of thermal radiation on the temperature around the sample plate 5, a temperature sensor can be arranged around the sample fixing frame 41, and an additional cooling component 7 can be arranged 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 rises due to temperature influence, cold air can be introduced into the additional cooling component 7 to further cool the gas around the sample plate 5.

[0067] Referring to the attached drawing 14 of the specification, based on the above test device, the present invention also provides a method for depositing static electricity on an aircraft skin material, including the following steps:

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

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

[0070] Step 3: Detect the particle concentration in the test tube 11 in real time, and use a flying safety meter to detect the ground discharge current value of the test sample plate 5;

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

[0072] Among them, based on the above test method, in order to analyze the relationship between the charging current and the particle concentration, the following configurations are made for the test in this embodiment:

[0073] The ultrasonic atomizing nozzle 211 selects an HT-908 two-fluid ultrasonic atomizer, adjusts the water pressure to 0.6 bar and the air pressure to 3.5 bar to generate water mist particles with a radius of 30 - 35 μm; the refrigerating delivery pipe 221 inputs cold air at -10 °C to solidify 30% of the water mist into ice crystals;

[0074] Apply a voltage of +200 kV to the polarization needle 231 to make the particles carry positive charges;

[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] The test 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 refrigerating assembly 22 generate ice crystal - water mist mixed particles, and the concentrations are set to 2×10 4 , 3×10 4 , 4×10 4 , 5×10 4 particles / m³ respectively; the laser dust particle counter monitors the particle concentration in real time, the flying safety meter records the discharge current value of the test sample plate 5, the intelligent anemometer calibrates the wind speed fluctuation within ±2 m / s, and the data acquisition system synchronously stores the current, concentration, temperature, humidity, and wind speed data.

[0078] The above test results are as follows:

[0079] The charging current increases linearly with the increase of the particle concentration (for example, 15.97 nA at 2×10 4 particles / m³ and 34.30 nA at 5×10 4 particles / m³), and the test data of this group are as shown in the appendix of the specification Figure 15As shown in the figure, the experimental data verified the mechanism that high-concentration charged particles exacerbate electrostatic accumulation, providing a basis for the risk assessment of aircraft passing through thunderstorm clouds.

[0080] Example 2: To simulate and verify the influence of the forward projection area on the charging current, the following configurations were made for the experiment in this example:

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

[0082] The inclination angle of the specimen fixing frame 41 was adjusted (45°, 60°, 75°, 90° in sequence), corresponding to the forward projection area of 0.05 m² to 0.071 m²;

[0083] The test panel 5 was a metal plate coated with ordinary aviation topcoat.

[0084] It should be noted that each time the inclination angle of the above-mentioned specimen fixing frame 41 was adjusted, the equipment needed to be restarted once. The flight safety meter recorded the charging current value of the test panel 5 in the stable state, and the test was repeated three times and the average value was taken.

[0085] The above test results are as follows:

[0086] The charging current increased significantly with the increase of the projection area. It was 412.81 nA at 0.05 m² and 612.55 nA at 0.071 m². The test data of this group are shown in the appendix of the specification, Figure 16 proving the influence of the aircraft attitude change on the electrostatic charging current and providing a basis for the course optimization design.

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

[0088] The ultrasonic atomizing nozzles 211 of the ultrasonic atomizer were successively selected as the atomizers with the nozzles of HT-908, HT-1008, and HT-2008 types to generate particles with a radius of 35 - 200 μm, and the particle concentration was 2×10 4 particles / m³;

[0089] The test panel 5 was a metal plate coated with ordinary aviation topcoat;

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

[0091] It should be noted that after fixing the test panel 5, the ultrasonic atomizing nozzles 211 of different nozzles were adjusted in sequence to generate particles with a radius of 35 - 200 μm, and then other equipment, and the discharge current values of each material were recorded.

[0092] The above test results are as follows:

[0093] When the particle radius is 30 μm, the charging current is 13.96 nA. When the particle diameter is 200 μm, the charging current is 530.14 nA. The test data of this group are as shown in the appendix of the specification 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, the present invention integrates an ultrasonic atomizer (such as HT-908 and HT-2008 series) with a polarized tip technology to generate ice crystal-water mist mixed charged particles, and accurately controls their radius, concentration and charge distribution; adopts a modular blowing system (i.e., wind tunnel system 1 with a wind speed of 50 m / s) to simulate a high-speed flight environment, and combines an adjustable inclination test platform to reproduce different forward projection areas; realizes multi-dimensional data synchronous acquisition through a high-precision flying safety meter, a laser particle counter and an environmental sensor, and is applicable to quantitatively analyzing the linear relationship between the charging current and the particle concentration, radius, wind speed, material type and forward projection area, providing a test basis for the antistatic design of the aircraft skin. It solves the bottlenecks in traditional methods such as rough particle generation, poor variable coupling, and single data dimension, provides a reliable platform for quantitatively analyzing the correlation law between the charging current and particle parameters, material types, and flight postures, and significantly improves the test efficiency and engineering guiding value.

[0095] The above describes the embodiments of this example, but this example is not limited to the above specific implementation manners. The above specific implementation manners are only illustrative and not restrictive. Under the inspiration of this example, those of ordinary skill in the art can also make many forms, all of which fall within the protection scope of this example.

Claims

1. An electrostatic deposition test device for aircraft skin materials, characterized in that: 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).

2. The electrostatic deposition test device for an aircraft skin material 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 electrostatic deposition test device for the aircraft skin material according to claim 2, wherein: 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. An electrostatic deposition test device for aircraft skin materials 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. An electrostatic deposition test device for an aircraft skin material according to claim 4, characterized in that: 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).

6. The electrostatic deposition test device for the aircraft skin material according to claim 5, characterized in that: The test tube (11) has a two-section structure. The transparent cylinder (6) is docked between the two test tubes (11). A docking cylinder (311) is fixedly connected to the mounting cover (31). The docking cylinder (311) is fixedly docked with the two test tubes (11). An external rotational support base (61) is fixedly connected to the transparent cylinder (6). The transparent cylinder (6) is rotationally mounted in the docking cylinder (311) through the rotational support base (61). The rotational drive (62) is a motor, and this motor is enclosed and mounted on the docking cylinder (311). An external gear ring structure is fixedly mounted on the rotational support base (61). A gear is provided on the output shaft of the motor, and this motor drives the transparent cylinder (6) to rotate through the cooperation of the gear and the gear ring.

7. An electrostatic deposition test device for an aircraft skin material according to claim 6, characterized in that: An air extraction cavity (312) is provided at the position of the docking cylinder (311) corresponding to the rear end of the transparent cylinder (6). An air extraction pipe (313) is provided on the air extraction cavity (312). The air extraction pipe (313) is connected to an air extraction pump structure. A water absorption slit (314) is provided at the position of the test tube (11) corresponding to the rear end of the transparent cylinder (6). The water absorption slit (314) protrudes relative to the inner wall of the rear end of the transparent cylinder (6). The water absorption slit (314) communicates with the air extraction cavity (312).

8. An electrostatic deposition test device for aircraft skin materials according to claim 7, characterized in that: The specimen fixing assembly (4) includes a specimen fixing frame (41) and a mounting frame (42). A slot for placing the test sample plate (5) is provided in the specimen fixing frame (41). The mounting frame (42) is fixedly mounted at one end of the test tube (11) away from the stabilizing tube (12), and the mounting frame (42) has a forward extending structure. The specimen fixing frame (41) is mounted at the forward extending end of the mounting frame (42) through an angle adjuster (43). The mounting frame (42) is used to adjust the angle of the specimen fixing frame (41).

9. An electrostatic deposition test device for an aircraft skin material according to claim 8, characterized in that: An activity cover (44) is slidably mounted behind the specimen fixing frame (41). Guide covers (441) are provided around the activity cover (44). The guide covers (441) are inclined backward. Negative pressure holes are provided in the specimen fixing frame (41) corresponding to the position of the test sample plate (5). A piston column (442) is fixedly connected to the activity cover (44) corresponding to the position of the negative pressure holes. The piston column (442) is slidably mounted in the negative pressure holes.

10. A method for depositing static electricity on an aircraft skin material, characterized in that, Using the test device as described in claim 9 for testing, includes the following steps: Step 1: Install the test sample plate (5) on the specimen fixing assembly (4), start the blower (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 and ice crystal particles in the stabilizing tube (12), and according to the air flow, make the above-mentioned charged particles rush towards the surface of the test sample plate (5); Step 3: Real-time detect the particle concentration in the test tube (11), and use a flying safety meter to detect the ground discharge current value of the test sample plate (5); Step 4: Real-time monitor the surface condition of the test sample plate (5) through the high-speed camera (32), and turn on the heating assembly (33) to heat the internal area of the mounting cover (31).

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