High-speed water impact resisting process method for water pressure sensor of large amphibious aircraft

Abstract

The invention relates to the technical field of aircraft water load test flight, in particular to a high-speed water impact resisting process method for a water pressure sensor of a large amphibious aircraft. According to the method, a mode of combining a high-strength aviation structural adhesive and a water-impact-resistant coating is adopted, so that the problem that a surface-bonded water pressure sensor is easy to wash away due to the adoption of a surface bonding process is effectively solved. By adding a certain amount of rigid nano-particles in the water impact resistant coating, the mechanical property and the bonding property of the surface coating are greatly improved, the risk that a bonding gap of the sensor is punctured by high-speed water is effectively avoided, the technical problem that the water pressure sensor cannot be used on the skin of the bottom of an airplane ship is solved, and the application prospect is wide. And large-scale full-aircraft water load measurement on a large amphibious aircraft by adopting a surface-bonded water pressure sensor becomes possible.

Description

Technical Field

[0001] The invention relates to the technical field of aircraft water load flight test, and relates to a process method for resisting high-speed water impact of a water pressure sensor of a large amphibious aircraft. Background Art

[0002] The landing part of an amphibious aircraft is subjected to complex water loads during takeoff and landing on water. The huge impact generated by the water loads will cause the hull to vibrate, and in severe cases, damage the aircraft structure. Therefore, it is crucial to develop aircraft water load test flight technology to describe the impact of this impact on the hull. The pressure measurement method is the most intuitive method to test the hull load distribution. Traditional pressure sensors cannot be used in large quantities on aircraft because they need to open holes in the bottom of the aircraft, which destroys the aircraft structure. Therefore, surface-mounted pressure sensors have become a potential technical solution for water load test flights of large amphibious aircraft. The speed of large amphibious aircraft landing is about 45m / s, and the impact pressure range is no more than 2MPa. The speed of traditional water impact-resistant coatings to resist water impact is 20-30m / s, and can only withstand short-term impact. Therefore, the existing impact resistance method is not suitable for large amphibious aircraft surface-mounted water pressure sensors in this field to resist high-speed water impact. Write down the high-speed water impact in this field, how big the impact force is, write down the approximate numerical range, and how big the traditional water impact force is, write down the range, so the existing impact resistance method is not suitable for large amphibious aircraft surface adhesive water pressure sensor in this field to resist high-speed water impact. However, the surface adhesive pressure sensor faces huge challenges during the installation process. In order to ensure that the sensor and cable do not damage the original structure of the aircraft during the installation process, the sensor and its cable cannot be connected and fixed to the aircraft skin by riveting, welding and slotting. Therefore, the bonding process becomes the only choice for the installation of such sensors and cables.

[0003] According to the actual working conditions of large amphibious aircraft landing on the sea, the installation process of sensors and cables needs to solve two problems. First, the compression strength, tensile lap shear strength and mechanical properties of the adhesive used to bond sensors and cables in a hot and humid environment must be much greater than the actual pressure when the aircraft lands on the water; at the same time, during the landing and high-speed hydroplaning process of the aircraft, the surface coating of the sensor and cable bonding area must also have the functions of waterproofing, high-speed water puncture resistance, wear resistance, and seawater corrosion resistance. Therefore, a surface-bonded sensor process installation method is urgently needed to solve the above problems. Summary of the invention

[0004] Purpose of the Invention

[0005] Aiming at the demand for water load measurement of full-scale large amphibious aircraft on water and at sea using surface-bonded water pressure sensors, the present invention proposes a process method for resisting high-speed water impact of surface-bonded water pressure sensors and their cables. The method adopts a combination of high-strength aviation structural adhesive and water impact-resistant coating, which effectively solves the problem that surface-bonded water pressure sensors are easily washed away due to the surface bonding process.

[0006] Technical Solution

[0007] In order to solve the above problems, a process method for resisting high-speed water impact of water pressure sensors of large amphibious aircraft is proposed. The method adopts a combination of high-strength aviation structural adhesive and water-impact resistant coating. The appropriate high-strength aviation structural adhesive is selected to enable the sensor to withstand the impact of the aircraft landing on the water. And by adding a certain content of rigid nanoparticles to the water-impact resistant coating, the mechanical properties and bonding properties of the surface coating itself are improved.

[0008] The following steps are involved:

[0009] Step S100 uses a paint stripper to remove the topcoat and primer at the designated position of the aircraft skin:

[0010] Through theoretical simulation, the installation location and number of water pressure sensors are determined according to the strength of water load. Use a clean rag dipped in acetone to remove surface contaminants such as grease, oil, and residual dirt from the designated locations on the skin (water pressure sensors and cables), and wait for the acetone to completely evaporate. Use tape to limit the paint stripping area at the location where paint stripping is required, and then use a brush dipped in paint stripper to apply it inside the tape limit area to remove the topcoat and primer at the designated locations on the aircraft skin.

[0011] Step S200: The patch type water pressure sensor coated with adhesive is glued to a designated position through a glue control device:

[0012] Before gluing, use a clean rag dipped in acetone to remove surface contaminants in the paint-stripped area before gluing the patch water pressure sensor and the cable, wait for the acetone to completely evaporate, and use paper tape to limit the gluing position of the patch water pressure sensor and the cable. The adhesive is specifically a high-strength aviation structural adhesive. The mixed adhesive is evenly applied to the gluing area of ​​the patch water pressure sensor, and the patch water pressure sensor coated with the adhesive is glued to the designated position of the aircraft skin.

[0013] Step S300: Cover the sensor cable with adhesive:

[0014] After the patch water pressure sensor is fixed, quickly use paper tape to fix the cable with the sleeve along the designated position of the aircraft skin. The cable should be tightly fitted with the aircraft skin when fixed. Then use high-strength aviation structure quick-drying glue to apply glue to the cable near the paper tape. After the quick-drying glue is cured, remove the paper tape and use high-strength aviation structure glue to fully cover the cable surface. The thickness and width of the adhesive should ensure that it will not affect the hydrodynamic force.

[0015] Step S400: Spraying resin on the bonding area: After the adhesive is cured, spray the resin on the bonding gap area of ​​the patch water pressure sensor and the adhesive cable covering area. First, mix the resin with the curing agent and the diluent, and then apply the resin to the covering area by brushing. After uniform mixing, apply the resin to the covering area by brushing. The curing temperature is room temperature and the curing time is 12 hours.

[0016] Step S500: spraying water impact resistant coating on the bonding area:

[0017] After the resin is half cured (after drying at room temperature for 2 hours), spray the water impact resistant coating on the patch glue gap area and the adhesive cable coverage area, that is, the state in which the resin is not fully cured, and spraying the coating again in this state can effectively increase the adhesion between the surface coating and the underlying resin. First, the inorganic particles, resin, curing agent and diluent are mixed, and then the resin is applied to the covering by brushing. Among them, the resin is a hydrophobic epoxy resin or a hydrophobic polyurethane. For hydrophobic epoxy resin, the curing agent is isophorone diamine, diethylenetriamine, etc., and for hydrophobic polyurethane, it is necessary to mix according to the two-component ratio.

[0018] Furthermore, Figure 1 It is a side view of the glue control device, which is characterized in that a glue control frame 1 is provided, a movable bottom plate 2 is placed inside the frame, and four height adjustment screws 3 are installed around the back of the frame to adjust the thickness of the glue layer. A spring ejector screw 4 is inserted from the center of the back of the frame to connect with the bottom plate. When gluing, the spring screw is slightly pressed to separate the sensor from the device.

[0019] Furthermore, when in use: place the patch sensor and cable according to the contour on the movable bottom plate 2 inside the glue control frame 1, and adjust the stroke of the four height adjustment screws 3 to adjust the distance between the sensor bonding surface and the surface of the frame 1. The shorter the distance, the smaller the amount of glue applied. Use a scraper to scrape off the excess glue along the bottom of the glue control device. When adjusting the screw distance, use a vernier caliper to measure the distance between the sensor and the surface of the frame to determine the thickness of the glue layer. Place the glue control device with a pressure sensor at a specified position on the bottom skin of the aircraft, and separate the clamp from the sensor by lightly pressing the spring ejector screw 4 on the back of the clamp.

[0020] Furthermore, in step S200, during gluing, the glue control device used here strictly controls the thickness of the glue layer between 0.1 mm and 0.2 mm, so as to reduce the influence of the excessively thick glue layer on the hydrodynamic measurement of the surface sensor of the outer skin of the bottom of the aircraft, and ensure that the glue layer thickness of the patch type water pressure sensor is uniform and consistent.

[0021] Furthermore, in step S300, the covering thickness is specifically controlled to be between 1.2 mm and 1.5 mm, and the covering width of the adhesive is controlled to be between 15 mm and 20 mm.

[0022] Further, in step S400, the resin is a hydrophobic epoxy resin or a hydrophobic polyurethane, and for the hydrophobic epoxy resin, the curing agent is isophorone diamine and diethylene triamine, and for the hydrophobic polyurethane, the components need to be mixed according to a proportion. The proportions between the epoxy resin, the curing agent, and the different components of the polyurethane resin need to be calculated according to a specific formula.

[0023] Furthermore, in step S500, the inorganic particles are alumina particles and silica particles, with a size of 1 to 100 microns, and the amount added is 30 to 60 wt.% of the resin. The diluent is ethyl acetate, butyl acetate, ethanol, etc., and the amount added is 1 to 2 times the weight of the resin. After uniform mixing, the resin is applied to the covering area by brushing, and the curing temperature is room temperature and the curing time is 12 hours.

[0024] Furthermore, for E-51 epoxy resin, the ratio is 100:8 when diethylenetriamine is used as a curing agent, and the ratio is 100:22 when isophorone diamine is used as a curing agent; the diluent is ethyl acetate, butyl acetate, ethanol, etc., and the added amount is 1 to 2 times the weight of the resin.

[0025] Furthermore, the brands of the paint stripper and the tape in step S100 are selected according to the materials of the aircraft topcoat, primer and skin. Since the paint stripper is highly corrosive, in order to prevent the paint surface of the limited area from being corroded by the paint stripper, a corrosion-resistant tape should be used according to the process specifications. Conventional paper tape can be used in the process of fixing and gluing the sensor and the optical cable.

[0026] Furthermore, in step S200, the adhesive components are mixed in strict accordance with the specified ratio at a specified temperature according to the adhesive material specification.

[0027] Furthermore, the material of the adhesive in step S200 is selected according to the aircraft skin material and the packaging material of the sensor.

[0028] The beneficial effects of this application are:

[0029] The present invention solves the technical problems that the existing surface-bonded water pressure sensor cannot be used in the aviation field because the adhesive is easy to be knocked off at the moment of landing due to poor mechanical properties during the landing of large amphibious aircraft and the waterproof coating at the sensor bonding gap is easy to be punctured by high-speed water during the landing and high-speed hydroplaning of the aircraft. Traditional fixed installation methods of sensors and cables such as riveting, welding and slotting will damage the original structure of the aircraft skin and cause damage, so they are not allowed to be used in the aviation field. Therefore, surface bonding becomes the only choice. The quick-drying glue of the commonly used sensor cannot meet the requirements of the aircraft landing due to its low mechanical properties. By selecting a suitable high-strength aviation structural glue, the sensor can withstand the impact of the aircraft landing; by adding a certain amount of rigid nanoparticles in the water-resistant impact coating, the mechanical properties and bonding properties of the surface coating itself are greatly improved, and the risk of the sensor bonding gap being punctured by high-speed water is effectively protected, which solves the technical problem that the water pressure sensor cannot be used on the bottom skin of the aircraft, making it possible to use the surface-bonded water pressure sensor to perform large-scale full-machine water load measurement on large amphibious aircraft. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a side view of the glue control device;

[0031] Among them: 1-frame, 2-movable bottom plate, 3-height adjustment screw, 4-spring ejector screw;

[0032] Figure 2 This is the surface microscopic morphology after the coating adhesion test;

[0033] Figure 3 Optical photographs of coating contact angle test;

[0034] Figure 4 This is the experimental effect diagram of the water impact resistant coating;

[0035] Figure 5 This is the Taber friction test result of the coating. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical scheme and advantages of the implementation of the present invention clearer, the technical scheme in the embodiment of the present invention will be described in more detail in combination with the embodiment of the present invention. In the example, the same or similar reference numerals throughout represent the same or similar originals or elements with the same or similar functions. The described embodiments are part of the embodiments of the present invention, not all of them. The embodiments described below by reference are exemplary and intended to be used to explain the present invention, and should not be construed as limitations on the present invention. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in the field without making creative work belong to the scope of protection of the present invention. The following is a detailed description in combination with the embodiments of the present invention.

[0037] Typically, 45 measuring points are installed in the water load concentration area to test the aircraft's water impact resistance process, of which 42 points use simulated patches without cables that are consistent with the water pressure sensor package shape, and 3 measuring points are water pressure sensors with cables. Use a clean rag dipped in acetone to remove pollutants such as grease, oil, and residual dirt near the 45 measuring points and 3 cables on the skin, and wait for the acetone to completely evaporate. Use paper tape to limit the paint stripping area at the location where paint stripping is required, and then apply a brush dipped in paint stripper to the inside of the tape limiting area to remove the topcoat and primer at the specified location of the aircraft skin. The brand of paint stripper and tape here is selected according to the material of the aircraft topcoat, primer and skin.

[0038] Before gluing, use a clean rag dipped in acetone to remove surface contaminants from the paint stripping area before gluing the sensor and cable, wait for the acetone to completely evaporate, and use tape to limit the gluing position of the sensor and cable. According to the supplier's adhesive material specifications, mix the adhesive components strictly according to the mixing ratio specified in the material specifications at the temperature specified in the material specifications. The adhesive here refers to high-strength aviation structural adhesive, and the selection of adhesive materials depends on the aircraft skin material and the packaging material of the sensor. The mixed adhesive is evenly applied to the sensor gluing area, and the 42 patch-type analog patches and 3 water pressure sensors with cables coated with adhesive are glued to the specified positions of the aircraft skin. During gluing, a special glue control device is used here to strictly control the thickness of the glue layer between 0.1mm and 0.2mm, and to ensure that the glue layer thickness of the entire aircraft sensor is uniform and consistent.

[0039] For the three water pressure sensors with cables, after the water pressure sensors are fixed, quickly use paper tape to fix the cables along the designated position of the aircraft skin. The cables must fit tightly against the aircraft skin when fixed. Then use high-strength aviation structural quick-drying glue to apply glue to the cables in the area near the paper tape. After the quick-drying glue is cured, remove the paper tape and use high-strength aviation structural glue to fully cover the surface of the cables. The covering thickness of the adhesive is controlled at 1.2mm to 1.5mm, and the covering width of the adhesive is controlled at 15mm to 20mm.

[0040] After the adhesive has been cured for 24 hours, spray the resin on the adhesive gap area of ​​the sensor and the adhesive cable covering area. First, mix the hydrophobic epoxy resin with the curing agent isophorone diamine and the diluent ethyl acetate. Among them, the content of isophorone diamine is 25wt.% of the resin, and the content of ethyl acetate is twice that of the resin. After uniform mixing, apply the resin to the covering area by brushing. The curing temperature is room temperature and the curing time is 12h.

[0041] After the resin is half cured (2h at room temperature), spray the water impact resistant coating on the patch glue gap area and the adhesive cable coverage area. First, mix the hydrophobic epoxy resin with the curing agent isophorone diamine, silica particles, and the diluent ethyl acetate. Among them, the content of isophorone diamine is 25wt.% of the resin, and the content of ethyl acetate is twice that of the resin. The size of the silica particles is ~5 microns, and the content is 40wt.% of the resin. After uniform mixing, the resin is applied to the coverage by brushing. The curing temperature is room temperature and the curing time is 12h.

[0042] The specific number and location of measuring points need to be adjusted accordingly according to different water load test flight plans. There are many ways to achieve this, and the final implementation result only needs to meet the above-mentioned sensor installation method and process flow.

[0043] The following experimental analysis or report, pure text description or with tables and corresponding data comparison, should be no less than three pages, in order to fully prove that the impact resistance brought by this method has been significantly improved. Comparative black and white effect pictures and other contents can be provided.

[0044] 1. Material selection for structural adhesives

[0045] Considering the actual working conditions of aircraft water load offshore testing, aviation structural adhesives need to have good compressive strength, shear strength, waterproof and corrosion resistance. Since the aircraft bottom skin and sensor packaging patches are both made of aluminum alloy, metal-bonded aviation structural adhesives become a potential option. The bonding strength properties of the selected adhesives are shown below:

[0046] 1.1 Tensile lap shear strength

[0047] The tensile lap shear strength at different test temperatures was tested according to ASTM D1002. The bond was made of bare 2024-T3 aluminum anodized with phosphoric acid according to ASTM D3933. The test data is shown in Table 1.

[0048] Table 1. Tensile lap shear strength at different test temperatures.

[0049] Test temperature (℃) Typical strength (MPa) -55 27.6 25 34.5 82 20.72 107 13.8 121 6.5

[0050] The tensile lap shear strength of the adhesive process variables (different adhesive curing schemes) at different test temperatures was tested according to ASTM D1002. The bond was 2024-T3AIClad aluminum anodized with phosphoric acid according to ASTM D3933. The test data is shown in Table 2:

[0051] Table 2. Tensile lap shear strength of different curing schemes.

[0052]

[0053] The tensile lap shear strength of the adhesive in dry, heat aged, hot / humid, aviation fuel and other environments was tested according to ASTMD1002. The bond was 2024-T3 AIClad aluminum anodized with phosphoric acid according to ASTM D3933 and sprayed with BR-127 primer. The test data is shown in Table 3:

[0054] Table 3. Tensile lap shear strength under different environments.

[0055]

[0056]

[0057] 1.2 Peel strength

[0058] Floating roller (bell) peel strength was tested according to ASTM D3167. The bond was 2024-T3 AIClad aluminum with a peel of 0.020 inches (0.51 mm) and a backing of 0.063 inches (1.6 mm), anodized with phosphoric acid and primed with BR-127 according to ASTM D3933. The test data is shown in Table 4:

[0059] Table 4. Floating roller (bell-shaped) peel strength.

[0060]

[0061] Peel strength was tested according to ASTM D1876. The bond was 2024-T3 bare 0.020 inch (0.51 mm) thick aluminum anodized with phosphoric acid according to ASTM D3933. The test data is shown in Table 5:

[0062] Table 5. T-Peel peel strength.

[0063]

[0064] 1.3 Compression strength

[0065] The test was conducted in accordance with ASTM D695 using cylindrical specimens with a height of 1.42 inches (36 mm) and a diameter of 0.56 inches (14.2 mm). The adhesive was cured for seven days at 77°F (25°C). The test data is shown in Table 6:

[0066] Table 6. Compression strength.

[0067]

[0068] Water impact resistant coating and high-speed water impact resistant test

[0069] Considering the actual working conditions of large amphibious aircraft water load sea test flight, it is necessary to spray a waterproof coating on the adhesive surface to prevent seawater corrosion, high-speed water puncture and physical friction. Good adhesion is the primary condition for long-term protection of the coating. This patent first tests the adhesion between the coating and the substrate. According to the characterization ASTM D3359, it can be observed that the adhesion between the coating and the substrate is good after being divided by a hundred-grid knife, and there is no shedding phenomenon1, so its adhesion level with the substrate is the highest 5B.

[0070] Then, the patent tests the contact angle of the coating, such as Figure 3 As shown, the contact angle between the coating and the surface is 156.3°, which is greater than 150°. The surface coating has good hydrophobic properties and reaches a super-hydrophobic state.

[0071] Subsequently, this patent tested and compared the water flow impact resistance of two types of densely packed super-hydrophobic coatings. In a laboratory environment, two adhesives were selected to bond a sensor patch with a thickness of 1mm at room temperature according to their respective process specifications. After curing, two coatings were sprayed on the bonding gap, and then a high-pressure water gun (maximum water outlet pressure 15MPa, maximum water outlet speed of about 130m / s) was used to flush the bonding gap of the test piece for 30s, 60s, and 90s respectively. The water outlet speed increased from 40m / , with an interval of 5m / s, and stopped at a maximum of 130m / s.

[0072] like Figure 2 As shown in the figure, the adhesives without super hydrophobic coating were washed away by water pressure under high-speed water impact, among which adhesive 1 was washed out of the gap, while only a small piece of adhesive 2 was washed away. The patches sprayed with water-resistant coating (coating 1 and coating 2) can withstand the impact of high-speed water pressure.

[0073] In addition, the super-hydrophobic coating prepared by this patent also has good friction resistance. The present invention uses a Taber friction machine to test the wear resistance of the coating. It can be found that the coating loses its super-hydrophobic property after friction 1000 times, indicating that the super-hydrophobic coating displayed by the present invention has good durability.

[0074] It is understood by those skilled in the art that, unless otherwise defined, all terms (including technical terms and scientific terms) used herein have the same meaning as the general understanding of ordinary technicians in the field to which the present invention belongs. It should also be understood that terms such as those defined in general dictionaries should be understood to have the same meaning as in the context of the prior art, and unless defined as here, will not be interpreted with idealized or overly formal meanings. The specific implementation methods described above further describe the purpose, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the present invention. Within the spirit and principle of the present invention, any technician familiar with the profession may use the above disclosed technical content to change or modify it into an equivalent embodiment of equivalent changes for application in other fields, but any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the technical solution content of the present invention, any modification, equivalent replacement, improvement, etc., made according to the technical essence of the present invention, should be included in the protection scope of the present invention.

Claims

1. A process for resisting high-speed water impact of a water pressure sensor of a large amphibious aircraft, characterized in that: By combining high-strength aviation structural adhesive with water-resistant impact coating, suitable high-strength aviation structural adhesive is selected to enable the sensor to withstand the impact of the aircraft landing on the water; and by adding a certain amount of rigid nanoparticles to the water-resistant impact coating, the mechanical properties and bonding properties of the surface coating itself are improved.

2. The method according to claim 1, characterized in that The following steps are involved: Step S100 uses a paint stripper to remove the topcoat and primer at the designated position of the aircraft skin: Through theoretical simulation, the installation location and number of water pressure sensors are determined according to the strength of water load; a clean rag dipped in acetone is used to remove surface pollutants at the designated location of the skin, and after the acetone is completely evaporated, tape is used to limit the paint removal area at the location where paint removal is required, and then a brush dipped in paint stripper is used to apply it inside the tape limit area to remove the topcoat and primer at the designated location of the aircraft skin; Step S200: The patch type water pressure sensor coated with adhesive is glued to a designated position through a glue control device: Before gluing, use a clean rag dipped in acetone to remove surface contaminants in the paint-stripped area before gluing the patch-type water pressure sensor and the cable, wait for the acetone to completely evaporate, and use paper tape to limit the gluing position of the patch-type water pressure sensor and the cable; the adhesive is specifically a high-strength aviation structural adhesive, and the mixed adhesive is evenly applied to the gluing area of ​​the patch-type water pressure sensor, and the patch-type water pressure sensor coated with the adhesive is glued to the designated position of the aircraft skin; Step S300: Cover the sensor cable with adhesive: After the patch water pressure sensor is fixed, quickly use paper tape to fix the cable with the sleeve along the designated position of the aircraft skin. The cable should be tightly fitted with the aircraft skin when fixed. Then use high-strength aviation structure quick-drying glue to apply glue to the cable near the paper tape. After the quick-drying glue is cured, remove the paper tape and use high-strength aviation structure glue to fully cover the cable surface. The thickness and width of the adhesive should ensure that it will not affect the hydrodynamic force. Step S400 sprays resin on the bonding area: after the adhesive is cured, spray the resin on the bonding gap area of ​​the patch water pressure sensor and the adhesive cable covering area; first mix the resin with the curing agent and the diluent, and then apply the resin to the covering area by brushing; after uniform mixing, apply the resin to the covering area by brushing, the curing temperature is room temperature, and the curing time is 12 hours; Step S500: spraying water impact resistant coating on the bonding area: After the resin is half cured, spray the water impact resistant coating on the patch bonding gap area and the adhesive cable coverage area, that is, the resin is not fully cured yet. Spraying the coating in this state can effectively increase the adhesion between the surface coating and the underlying resin; first, mix the inorganic particles, resin, curing agent and diluent, and then apply the resin to the coverage by brushing; the resin is a hydrophobic epoxy resin or a hydrophobic polyurethane. For the hydrophobic epoxy resin, the curing agent is isophorone diamine and diethylenetriamine. For the hydrophobic polyurethane, it needs to be mixed according to the ratio of the two components.

3. The method according to claim 2, characterized in that The glue control device includes a frame, a movable bottom plate is placed inside the frame, and four height adjustment screws are installed around the back of the frame to adjust the thickness of the glue layer. A spring ejector screw is inserted from the center of the back of the frame to connect with the bottom plate. The spring screw is slightly pressed during gluing to separate the sensor from the device. When in use: the patch sensor and the cable are placed on the movable bottom plate inside the glue control frame according to the profile. The distance between the sensor gluing surface and the frame surface is changed by adjusting the stroke of the four height adjustment screws. The shorter the distance, the smaller the amount of glue applied. The excess glue is scraped off along the bottom of the glue control device using a scraper. When adjusting the screw distance, the distance between the sensor and the frame surface is measured with a vernier caliper to determine the thickness of the glue layer. The glue control device with a pressure sensor is placed at a specified position on the bottom skin of the aircraft. The clamp is separated from the sensor by slightly pressing the spring ejector screw on the back of the clamp.

4. The method according to claim 3, characterized in that In step S200, during gluing, the glue control device used here strictly controls the thickness of the glue layer between 0.1mm and 0.2mm to reduce the influence of the excessively thick glue layer on the hydrodynamic measurement of the aircraft bottom outer skin surface sensor, and ensure that the glue layer thickness of the patch type water pressure sensor is uniform and consistent.

5. The method according to claim 4, characterized in that In step S300, the covering thickness is specifically controlled to be between 1.2 mm and 1.5 mm, and the covering width of the adhesive is controlled to be between 15 mm and 20 mm.

6. The method according to claim 5, characterized in that In step S400, the resin is a hydrophobic epoxy resin or a hydrophobic polyurethane. For the hydrophobic epoxy resin, the curing agent is isophorone diamine and diethylene triamine. For the hydrophobic polyurethane, the components need to be mixed according to the proportion; the proportions between the epoxy resin and the curing agent and the different components of the polyurethane resin need to be calculated according to the specific formula.

7. The method according to claim 6, characterized in that In step S500, the inorganic particles are alumina particles and silica particles with a size of 1 to 100 microns, and the addition amount thereof is 30 to 60 wt.% of the resin; the diluent is ethyl acetate, butyl acetate, and ethanol, and the addition amount is 1 to 2 times the weight of the resin; after uniform mixing, the resin is applied to the covering area by brushing, the curing temperature is room temperature, and the curing time is 12 hours; for E-51 epoxy resin, when diethylenetriamine is used as a curing agent, the ratio is 100:8, and when isophorone diamine is used as a curing agent, the ratio is 100:22; the diluent is ethyl acetate, butyl acetate, and ethanol, and the addition amount is 1 to 2 times the weight of the resin.

8. The method according to claim 7, characterized in that In step S100, the brands of the paint stripper and tape are selected according to the materials of the aircraft topcoat, primer and skin; since the paint stripper is highly corrosive, in order to prevent the paint surface in the limited area from being corroded by the paint stripper, corrosion-resistant tape should be used according to the process specifications; during the process of fixing and gluing the sensor and the optical cable, conventional paper tape can be used.

9. The method according to claim 8, characterized in that In the step S200, the adhesive components are mixed in strict accordance with the specified ratio at the specified temperature according to the adhesive material specification.

10. The method according to claim 9, characterized in that The material of the adhesive in step S200 is selected according to the aircraft skin material and the packaging material of the sensor.

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