Thermal flow oxygen salt five-field combined cross-sea-area high-speed flight simulation working condition experimental testing device and method

Abstract

The invention discloses a thermal flow oxygen salt five-field combined cross-sea-area high-speed flight simulation working condition experimental testing device and method, and belongs to the field of material testing. The device is used in cooperation with a universal testing machine, a fan, an electromagnetic induction heating module, an oxygen supply module, a salt mist generation module, a temperature / deformation field measurement module and an environmental parameter measurement module are arranged inside and outside a high-speed airflow circulation loop, and a sample is loaded through the universal testing machine and placed in an experiment section in the high-speed airflow circulation loop. Wide-temperature-range closed-loop control of the temperature of the sample, construction of a comprehensive stress state and construction of a controllable high-speed airflow, adjustable oxygen concentration and salt mist concentration gas environment are realized, so that a real material application environment is simulated, and acquisition of data of a temperature field, a deformation field and an oxidation corrosion field of the sample can be completed in a reaction process; the problem that a cross-sea-area high-speed aircraft service condition environment full-state simulation test cannot be realized in the prior art is solved.

Description

Technical Field

[0001] The present invention relates to the field of material testing, and specifically to an experimental testing device and method for a five-field combined cross-sea high-speed flight simulation working condition. The device specifically simulates the complex working condition of high temperature, complex stress, high-speed airflow, oxidation, and salt spray corrosion combined cross-sea high-speed flight. Background Art

[0002] Currently, technological competition in the field of high-end equipment is intensifying worldwide. High-speed aircraft, with their superior penetration capabilities, rapid response speed, and high efficiency, have become a focal point of competition. When high-speed aircraft enter service, the structural strength of materials in extreme service environments is a significant constraint in the development of high-speed flight technology. In actual service, these aircraft must not only withstand extreme loads such as high temperature, oxidation, airflow, vibration, and complex stresses, but also withstand the erosion of marine salt spray in cross-ocean environments. These factors can lead to structural failures such as pitting, oxidation defects, thermal cracks, and interfacial delamination, accelerating the degradation of mechanical properties such as strength and toughness, reducing the lifespan and reliability of the aircraft structure, and even directly leading to its destruction. Understanding the damage formation and evolution mechanisms of cross-ocean high-speed aircraft material structures under the coupled multi-field conditions of high temperature, complex stress, high-speed airflow, oxygen, and salt spray is a key prerequisite for guiding the design of high-speed aircraft materials. For a long time, the experimental test equipment for simulating actual working conditions of high-speed aircraft involved in existing research at home and abroad has mainly focused on the simulation of simple coupled working conditions in a single state or two states, and has failed to fully consider the extreme states of multi-field coupling under the actual working conditions of high-speed aircraft. There has been no report at home and abroad on the simulation experimental test equipment that can realize the full-state coupling of heat, force, flow, oxygen and salt.

[0003] Therefore, it is necessary to provide an experimental test device that can be used for full-state simulation of the real working conditions of cross-sea high-speed aircraft to solve the above problems. Summary of the Invention

[0004] Technical issues to be solved: In order to avoid the shortcomings of the existing technology, the present invention provides a thermal flow, oxygen, salt and five-field combined cross-sea high-speed flight simulation working condition experimental testing device and method. By arranging a fan, an electromagnetic induction heating module, an oxygen supply module, a salt spray generating module, a temperature / deformation field measurement module and an environmental parameter measurement module inside and outside the high-speed airflow circulation loop, the sample is loaded into the experimental section in the high-speed airflow circulation loop through a universal testing machine, so as to realize wide temperature range closed-loop control of the sample temperature, construction of a comprehensive stress state, construction of a controllable high-speed airflow, and construction of a gas environment with adjustable oxygen concentration and salt spray concentration, thereby simulating a real material application environment, and completing the collection of sample temperature field, deformation field and oxidation corrosion field data during the reaction process, thereby solving the existing problems.

[0005] The technical solution of the present invention is: a thermal flow, oxygen, salt five-field combined cross-sea high-speed flight simulation working condition experimental test device, comprising: A high-speed airflow circulation loop is formed by a circular hollow shell, and the shell of the high-speed airflow circulation loop is horizontally fixed on the side column of the universal testing machine; A fan is placed inside the high-speed airflow circulation loop to ensure that the internal airflow flows at a set flow rate; Electromagnetic induction heating module, used to heat the sample located in the high-speed airflow circulation loop; An oxygen supply module is used to introduce a set concentration of oxygen into the high-speed airflow circulation loop; A salt mist generating module is used to introduce salt mist of a set concentration into the high-speed airflow circulation loop; Environmental parameter measurement module, used to monitor gas flow rate, oxygen concentration, gas pressure and salt spray concentration in the high-speed airflow circulation loop; Temperature field measurement module, used to measure the temperature field of the sample in the high-speed airflow circulation loop; Deformation field measurement module, used to measure the deformation image and corrosion field image of the sample in the high-speed airflow circulation loop; and a computer for receiving, displaying and storing the measurement data collected by the environmental parameter measurement module, the temperature field measurement module and the deformation field measurement module, and processing the sample deformation image collected by the deformation field measurement module into displacement field and strain field data; Among them, the experimental section in the high-speed airflow circulation loop is used to install the sample, and the two ends of the sample vertically passing through the experimental section are connected to the corresponding chucks of the universal testing machine.

[0006] A further technical solution of the present invention is: the electromagnetic induction heating module includes an electromagnetic induction coil and a PID controller, the electromagnetic induction coil is electrically connected to the PID controller, the electromagnetic induction coil is placed outside the experimental section in the high-speed airflow circulation loop, and is placed at a certain distance from the outer shell of the high-speed airflow circulation loop, the electromagnetic induction coil is used to heat the sample in the experimental section, and the PID controller is used to control the heating temperature of the electromagnetic induction coil.

[0007] A further technical solution of the present invention is: the oxygen supply module includes an oxygen-depleted tank and an oxygen-enriched tank, and the gas outlets of the oxygen-depleted tank and the oxygen-enriched tank are both connected to the high-speed airflow circulation loop through pipelines and connectors.

[0008] A further technical solution of the present invention is: the salt spray generating module includes an atomizing spray gun, a saturator, an oil-water separator, an air compressor and a brine tank, wherein the air compressor is used to compress air, the oil-water separator is used to purify the compressed air, the saturator is used to humidify and heat the purified compressed air, the brine tank is used to store brine, the nozzle of the atomizing spray gun is connected to a high-speed airflow circulation loop, the atomizing spray gun is used to suck out the brine in the brine tank through negative pressure when the compressed air is sprayed out of the nozzle, and the brine is atomized and sprayed into the high-speed airflow circulation loop.

[0009] A further technical solution of the present invention is: the environmental parameter measurement module includes a gas flow rate sensor, an oxygen concentration sensor, a gas pressure sensor, a salt spray concentration sensor and a data acquisition card, wherein the gas flow rate sensor, the oxygen concentration sensor, the gas pressure sensor and the salt spray concentration sensor are all placed in a high-speed airflow circulation loop and are respectively used to sense the flow rate, oxygen concentration, pressure and salt spray concentration of the gas in the loop; the gas flow rate sensor, the oxygen concentration sensor, the gas pressure sensor and the salt spray concentration sensor are all connected to the data acquisition card through lines and are used to feed back collected data to the data acquisition card; the data acquisition card is connected to a computer, and the data acquisition card converts the collected data into signals and transmits them to the computer.

[0010] A further technical solution of the present invention is: the temperature field measurement module includes an IRT camera, the IRT camera is connected to a computer and controlled by the computer, the IRT camera is used to collect the temperature field of the sample in the high-speed airflow circulation loop, and feed the collected data back to the computer.

[0011] A further technical solution of the present invention is: the deformation field measurement module includes multiple light sources and multiple DIC cameras, and the multiple DIC cameras are all connected to a computer. The light sources are used to provide a lighting environment for the DIC cameras to shoot. The DIC cameras are used to collect deformation and corrosion field images of the sample in the high-speed airflow circulation loop during the experiment, and feed the collected images back to the computer.

[0012] A further technical solution of the present invention is that a pressure relief valve is installed on the shell of the high-speed airflow circulation loop, and the pressure relief valve is used to adjust the air pressure inside and outside the loop.

[0013] A further technical solution of the present invention is that the high-speed airflow circulation loop is provided with a contraction section immediately in front of the experimental section along the airflow direction, and the curve of the contraction section adopts a Vickers curve.

[0014] A method for testing a thermal flow, oxygen, and salt five-field combined cross-sea high-speed flight simulation working condition experiment comprises the following steps: Step 1. Sample preparation: The material to be studied is processed into a strip sample with notches symmetrically arranged on both sides of the middle; Step 2. Specimen Installation: Install the specimen vertically in the test section of the high-speed airflow loop, ensuring the notch in the middle of the specimen is located in the vertical center of the test section. Clamp the specimen at its upper and lower ends using the upper and lower chucks of a universal testing machine. Seal the specimen where it exits the housing of the high-speed airflow loop. Step 3. Air tightness check: Check the air tightness of the entire high-speed airflow circulation loop; Step 4. Determine the oxygen concentration and salt spray concentration of the sample test environment: According to the oxygen concentration, gas flow rate and temperature of the actual working environment, the oxygen concentration in the experimental environment is obtained when the gas flow rate and sample temperature are set in the experimental environment; According to the reaction time and corrosion current of the actual working environment, the corrosion current in the experimental environment is obtained under the condition of setting the reaction time of the experimental environment, and then the salt spray concentration is obtained from the corrosion current in the experimental environment; Step 5. Corrosion test simulating real working conditions: Based on the oxygen concentration and salt spray concentration of the experimental environment obtained in step 4, as well as the set four parameter values ​​of the sample temperature and gas flow rate of the experimental environment, an experimental environment is created in the high-speed airflow circulation loop so that the temperature of the sample in the loop and the flow rate, oxygen concentration, and salt spray concentration of the gas in the loop reach the set parameter values; after the environmental parameter measurement module detects that the environmental parameters are stable, a corrosion experiment simulating real working conditions is started to collect sample corrosion field data; Step 6. After the experiment in step 5 is completed, turn off the switches of each component in the device and remove the sample; Step 7. Test of mechanical properties of specimens: Mechanical properties test of the specimen: Speckles are made on the specimen taken out in step 6. The two ends of the specimen with speckles are re-clamped on the two chucks of the universal testing machine. The universal testing machine is set to uniformly stretch the specimen, and the full-field deformation data of the specimen is collected to complete the mechanical properties test experiment of the specimen.

[0015] The beneficial effects of the present invention are as follows: the present invention provides a thermal, flow, oxygen, and salt five-field combined cross-sea high-speed flight simulation working condition experimental test device, which can realize the material behavior experimental test of the extreme service working conditions of the thermal, force, flow, oxygen, and salt five-field coupling for high-speed aircraft, and can construct a state of the combined action of the five fields of high temperature, comprehensive stress state, high-speed airflow scouring, oxidation, and salt spray corrosion of the specimen, which is closer to the full-state simulation of the real working conditions of the aircraft's cross-sea high-speed flight, ensuring the accuracy of the experiment.

[0016] The experimental method of the present invention proposes a reduced-order acceleration equivalent experimental method. By using a modified oxidation reaction rate calculation formula, the temperature and oxygen concentration of the simulated experimental environment are increased to achieve a reasonable reduction in gas flow rate parameters in the experimental environment, thereby reducing the flow rate requirements in the experimental device and reducing the difficulty of implementing a high-speed airflow circulation loop device. At the same time, by establishing an equation with the same reaction corrosion degree in the real working environment and the experimental simulation environment, the specific value of the salt spray concentration is reversely solved according to the total duration of the simulation experiment and Faraday's law, thereby completing the acceleration of the experiment.

[0017] The experimental testing device proposed in the present invention can realize non-contact collection of specimen temperature field, deformation field, and oxidation corrosion field data during the reaction process, and complete the correlation matching of full-field data, so as to analyze the damage mechanism of cross-sea high-speed aircraft materials under the action of heat-force-flow-oxygen-salt multiple fields. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0019] Figure 1 This is a schematic diagram of the overall structure of a thermal flow, oxygen, salt, five-field combined cross-sea high-speed flight simulation working condition experimental test device of the present invention; Figure 2 Schematic diagram of the structure of the high-speed airflow circulation loop in the present invention (including a front view and a top view); Figure 3 for Figure 2 middle Ⅰ A magnified view of the structure; Figure 4 for Figure 2 middle Ⅱ A magnified view of the structure ( Ⅱ Chuwei Ⅰ the overlooking structure); Figure 5 It is the Vickers curve diagram of the contraction segment; Figure 6 It is the full field data of the sample's temperature field, deformation field and oxidation corrosion field.

[0020] In the figure: 1. Light source; 2. DIC camera; 3. IRT camera; 4. Chuck of universal testing machine; 5. Specimen; 6. Electromagnetic induction coil; 7. Gas flow rate sensor; 8. Oxygen concentration sensor; 9. Gas pressure sensor; 10. Data acquisition card; 11. Salt spray concentration sensor; 12. Fan; 13. High-speed airflow circulation loop; 14. Atomizing spray gun; 15. Saturator; 16. Oil-water separator; 17. Air compressor; 18. Brine tank; 19. Oxygen-deficient tank; 20. Oxygen-enriched tank; 21. Pressure relief valve; 22. PID controller; 23. Computer; 24. Corner guide plate; 25. Honeycomb; 26. Rectifier network; 27. Contraction section; 28. Latch clamp; 29. ​​Reaction zone; 30. Test observation window; 31. T-joint; 32. Sealed hatch; 33. Hinge structure; 34. Experimental section. DETAILED DESCRIPTION

[0021] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0022] Example 1: This embodiment provides a thermal flow, oxygen, salt and five-field combined cross-sea high-speed flight simulation working condition experimental test device, such as Figure 1-Figure 4 As shown, the device is used in conjunction with a universal testing machine, and specifically includes: a high-speed airflow circulation loop 13, a fan 12, an electromagnetic induction heating module, an oxygen supply module, a salt spray generation module, an environmental parameter measurement module, a temperature field measurement module, a deformation field measurement module and a computer 23.

[0023] Specifically, the high-speed airflow circulation loop 13 is a gas circuit formed by a hollow, meandering shell. The shell of the high-speed airflow circulation loop 13 is horizontally fixed to the side posts of the universal testing machine via a connecting device. A test area 34 is provided within the high-speed airflow circulation loop 13. The actual operating conditions of the test material are simulated within the high-speed airflow circulation loop 13. Tests on the material are conducted by placing a sample 5 of the test material within the test area 34. The sample 5 vertically extends through the test section 34 of the high-speed airflow circulation loop 13, and its ends are secured by the upper and lower chucks 4 of the universal testing machine.

[0024] Fan 12 is a high-speed fan, positioned within high-speed airflow circulation loop 13, and configured to achieve a predetermined flow rate within high-speed airflow circulation loop 13. The airflow direction within high-speed airflow circulation loop 13 is the wind direction generated by fan 12, with the wind direction of fan 12 being the front of the fan, and the front and rear of fan 12 being defined.

[0025] The electromagnetic induction heating module is located outside the high-speed airflow circulation loop 13 and is used to heat the sample located within the high-speed airflow circulation loop. Furthermore, the electromagnetic induction heating module includes an electromagnetic induction coil 6 and a PID controller 22. The electromagnetic induction coil 6 is electrically connected to the PID controller 22. The electromagnetic induction coil 6 is placed outside the experimental section 34 in the high-speed airflow circulation loop 13 and is placed at a certain distance from the outer shell of the high-speed airflow circulation loop 13. The electromagnetic induction coil 6 is used to heat the sample within the experimental section 34, and the PID controller 22 is used to control the heating temperature of the electromagnetic induction coil 6.

[0026] The oxygen supply module is used to introduce an adjustable concentration of oxygen into the high-speed airflow circulation loop. The oxygen supply module includes an oxygen-depleted tank 19 and an oxygen-enriched tank 20. The gas in the oxygen-enriched tank 20 is rich in oxygen, with an oxygen content higher than 21%. The oxygen content in the oxygen-depleted tank 19 is controlled to be below 5%. The air outlets of the oxygen-depleted tank 19 and the oxygen-enriched tank 20 are both connected to the same three-way joint 31 through pipelines, and then connected to the high-speed airflow circulation loop 13 through the three-way joint. The air outlets of the oxygen-depleted tank 19 and the oxygen-enriched tank 20 are both equipped with air valve switches. The concentration of oxygen entering the circuit is adjusted by adjusting the opening of the air valve switches of the oxygen-depleted tank 19 and the oxygen-enriched tank 20. In this embodiment, the three-way joint 31 is connected to the rear of the fan 12.

[0027] The salt mist generating module is used to introduce salt mist of adjustable concentration into the high-speed airflow circulation loop 13. The salt mist generating module includes an atomizing spray gun 14, a saturator 15, an oil-water separator 16, an air compressor 17, and a brine tank 18. The air compressor 17 compresses air, the oil-water separator 16 purifies the compressed air, the saturator 15 humidifies and heats the purified compressed air, and the brine tank 18 stores brine. The nozzle of the atomizing spray gun 14 is connected to the high-speed airflow circulation loop 13. When the compressed air is ejected from the nozzle, the atomizing spray gun 14 is used to draw the brine from the brine tank 18 through negative pressure, and then atomize the brine and spray it into the high-speed airflow circulation loop 13. The atomizing spray gun 14 is connected to the high-speed airflow circulation loop 13 in front of the fan 12. The salt mist concentration of the gas within the loop is adjusted by adjusting the brine concentration in the brine tank 18.

[0028] The environmental parameter measurement module is used to monitor the gas flow rate, oxygen concentration, gas pressure, and salt spray concentration within the high-speed airflow circulation loop 13. The environmental parameter measurement module includes a gas flow rate sensor 7, an oxygen concentration sensor 8, a gas pressure sensor 9, a salt spray concentration sensor 11, and a data acquisition card 10. These sensors are all placed within the high-speed airflow circulation loop 13, in front of the experimental section 34, specifically between the salt spray generating module and the experimental section 34. These sensors are used to sense the flow rate, oxygen concentration, pressure, and salt spray concentration of the gas within the loop, respectively. These sensors are all connected to the data acquisition card 10 via circuits, feeding collected data back to the card. The data acquisition card 10 is connected to a computer 23, which converts the collected data into digital signals, which are then transmitted to the computer 23 for display and storage.

[0029] The temperature field measurement module is used to measure the temperature field of the sample within the high-speed airflow circulation loop. It includes an IRT camera 3, located outside the high-speed airflow circulation loop 13 and facing the experimental area 34. The IRT camera 3 is connected to a computer 23 and collects temperature field data of the sample 5 within the high-speed airflow circulation loop 13. The collected data is fed back to the computer 23 for storage and display. Based on the temperature data displayed by the computer 23, the PID controller 22 is used to control the electromagnetic induction coil 6 to increase or decrease the temperature to ensure that the sample 5 is maintained at the set temperature environment.

[0030] The deformation field measurement module is used to measure the deformation and corrosion field of the specimen within the high-speed airflow circulation loop. In this embodiment, the deformation field measurement module includes two light sources 1 and two DIC cameras 2, both located outside the high-speed airflow circulation loop 13 and near the experimental area 34. Both the light sources 1 and the DIC cameras 2 are connected to a computer 23. The light sources 1 provide the necessary lighting for the DIC cameras 2 to capture images of the deformation and corrosion field of the specimen 5 within the high-speed airflow circulation loop 13 during the experiment. The captured information is fed back to the computer 23 for display and storage. The computer 23 then processes the specimen deformation image information into displacement and strain field data.

[0031] A pressure relief valve 21 is installed on the housing of the high-speed airflow circulation loop 13 , and the pressure relief valve 21 is used to adjust the air pressure inside and outside the loop.

[0032] In the high-speed airflow circulation loop 13, a contraction section 27 is provided in the front section immediately before the experimental section 34 along the airflow direction. The curve of the contraction section 27 adopts a Vickers curve. By setting the contraction section 27, the gas flow rate is increased proportionally to improve the efficiency of airflow flushing. The contraction section 27 reduces the flow rate of the incident air flow to Increase the velocity of the outgoing air flow According to the total flow Bernoulli equation:

[0033] Where: is the gas pressure of the incident airflow, is the gas pressure of the outgoing airflow, is the gas velocity of the incident airflow, is the gas velocity of the outgoing airflow, It is the additional input gas pressure (i.e. the input of specific concentration of oxygen and gas input at the salt spray generation module).

[0034] See Figure 5 The characteristic curve of the contraction section 27 is proposed to adopt the Vickers curve, which has good velocity uniformity and axial static pressure gradient. The equation of the contraction section 27 is:

[0035] The above formula is an empirical formula for the design of the Vickers curve-shaped contraction section 27. The axis of the cross section of the contraction section 27 is the x-axis, and the abscissa of any point on the Vickers curve is x. K is the ordinate of any point on the Vickers curve, i.e., the distance from the curve to the axis. 、 are the maximum and minimum distances from the Vickers curve to the axis in the contraction section, respectively. is the gas compression rate in the contraction section, .

[0036] The computer 23 is used to receive, process and display the measurement data collected by the environmental parameter measurement module, the temperature field measurement module and the deformation field measurement module.

[0037] To ensure airflow stability within the high-speed airflow circulation loop 13, corner deflectors 24, honeycombs 25, and a rectifier mesh 26 are also installed. Four sets of corner deflectors 24 are installed at the four 90-degree turns of the gas circulation loop 13, ensuring smooth 90-degree turns of the airflow and minimizing energy loss. The honeycombs 25 are installed in the straight line loop just before the converging section 27 along the airflow direction. The rectifier mesh 26 is installed just after the honeycombs 25 and before the converging section 27 along the airflow direction. The honeycombs 25 primarily break up large-scale vortices and transverse velocity components, forcing the airflow to flow along the axis of the honeycomb channels. The rectifier mesh 26 primarily reduces the turbulence intensity of the airflow, further improving its direction.

[0038] like Figure 4 As shown, in order to facilitate the installation of the sample 5 in the experimental section 34, the experimental section 34 is a straight section immediately after the contraction section 27. A sealed hatch 32 is provided on the inner side of the experimental section 34. The sealed hatch 32 is a double-leaf structure. Both sides of the two hatches are hinged to the shell of the high-speed airflow circulation loop 13 through a hinge structure 33 to achieve rapid opening and closing of the sealed hatch 32. At the same time, a latch-type clamp 28 is installed on the top of the two sealed hatches 32. The latch-type clamp 28 is used to lock the sealed hatch 32. Combined with reasonable sealing measures, it can be ensured that the gas in the high-speed airflow circulation loop 13 will not leak at the sealed hatch 32. At the same time, sealing rings are installed at both ends of the sample 5. The sealing rings are used to seal the gap between the sample 5 and the corresponding openings of the upper and lower shells of the experimental section 34, thereby avoiding gas leakage in the high-speed airflow circulation loop 13. When installing the sample 5, the sealed hatch 32 can be opened quickly to ensure that the central area of ​​interest of the sample 5 is located in the reaction zone 29 of the experimental section 34, that is, Figure 3 and Figure 4 The dotted box in the experimental section 34 is shown. To facilitate observation of the real-time status of the specimen 5 within the reaction zone 29, a test observation window 30 is provided outside the experimental section 34. The region of interest of the specimen 5 can be observed through the test observation window 30. The lens of the DIC camera 2 is directed toward the test observation window 30, enabling measurement of the specimen's deformation and corrosion field.

[0039] Example 2: This embodiment provides a method for testing a thermal flow, oxygen, and salt five-field combined cross-sea high-speed flight simulation working condition experiment. The test method uses the experimental test device in Example 1 and includes the following steps: Step 1. Preparation of Specimen 5: The material to be studied is processed into a rectangular strip-shaped specimen 5 with symmetrical notches on either side of the center. (This shaped specimen structure is only an example; other structures are also possible.) The notched area in the center of Specimen 5 is the region of interest, or the observation area. Under uniaxial tension, Specimen 5 can be subjected to combined stress states, such as tension-shear or tension-compression. In this example, 2024 aluminum alloy is used as the material for Specimen 5.

[0040] Step 2. Specimen Installation: Adjust the crossbar height of the universal testing machine to the appropriate position, open the latch clamp 28, open the sealing hatch 32, and after fitting sealing rings on both ends of the specimen 5, clamp the ends of the specimen 5 with the upper and lower chucks 4 of the universal testing machine. Ensure that the region of interest of the specimen 5 is located in the reaction zone 29 of the experimental section of the high-speed airflow circulation loop 13, and that the region of interest of the specimen 5 can be observed through the test observation window 30. Close the sealing hatch 32, close the latch clamp 28, and use sealing tape to seal the junction of the sealing hatch 32 and the airflow circulation loop 13. The sealing rings fitted on both ends of the specimen 5 achieve a seal where the specimen passes through the housing of the high-speed airflow circulation loop 13.

[0041] Step 3. air tightness check: check the air tightness of the high-speed airflow circulation loop. If the air tightness check fails, the leaking part is airtightly sealed. Specifically, turn on the power supply of the fan 12 to generate an airflow with a certain flow rate in the loop. Open the 19 air valves of the oxygen-depleted tank, pass gas into the high-speed airflow circulation loop 13, and check the air tightness of the high-speed airflow circulation loop 13 as a whole. After the air tightness check passes, close the air valve of the oxygen-depleted tank 19 and the power supply of the fan 12, open the pressure relief valve 21, and discharge the extra oxygen from the oxygen-depleted tank 19 in the loop through the pressure relief valve 21, so that the internal pressure of the high-speed airflow circulation loop 13 is reduced to atmospheric pressure. The exhaust can be detected by the gas pressure sensor 9 of the environmental parameter measurement module.

[0042] Step 4. Determine the oxygen concentration and salt spray concentration of the sample test environment: According to the oxygen concentration, gas flow rate and temperature of the actual working environment, the oxygen concentration in the experimental environment is obtained when the gas flow rate and sample temperature are set in the experimental environment.

[0043] According to the reaction time and corrosion current of the real working environment, the corrosion current in the experimental environment is obtained when the reaction time of the experimental environment is set, and then the salt spray concentration is obtained from the corrosion current in the experimental environment.

[0044] Specifically, to ensure that the oxidation reaction rates in the simulated experimental environment and the real working environment are the same, and to reduce the difficulty of establishing high-speed circulating airflow conditions in the experimental environment, it is necessary to substitute the parameters of the real working environment (including oxygen concentration, gas flow rate, and temperature) into the modified Arrhenius equation and solve for the equivalent parameters of the experimental environment (including oxygen concentration). The oxidation reaction rates in the experimental environment and the real working environment should be:

[0045] Where, A is the prefactor (frequency factor), which is a constant related to the reaction; is a natural constant; is the activation energy, a constant related to the reaction; R is the gas constant; is the absolute temperature in the simulated experimental environment, is the absolute temperature in the actual working environment; n is the reaction order of oxygen, which is a constant related to the specific reaction; is the equivalent oxygen concentration in the experimental environment is the equivalent oxygen concentration in the actual working environment, where , , is the molar concentration of oxygen in the experimental environment, is the molar concentration of oxygen in the actual working environment, is the air flow velocity in the experimental environment is the air flow velocity in the actual working environment, is the sensitivity coefficient of gas flow rate, which is a constant. The above formula can be simplified as:

[0046] The known temperature in the experimental environment , gas flow rate and the temperature in the actual working environment , oxygen molar concentration , gas flow rate Substitute the above formula to solve the oxygen molar concentration in the simulated experimental environment .

[0047] Sample 5 undergoes an electrochemical reaction with salt spray. Faraday's law can be used to deduce the numerical value of the simulated experimental salt spray concentration. The known conditions are the experimental reaction time, the actual working condition reaction time, and the actual working condition salt spray concentration. According to Faraday's law, the following equation should be obtained:

[0048] Where: F is the Faraday constant; For the reaction time in high-speed aircraft environment experiments, is the reaction time in a real working environment, Corrosion current in high-speed aircraft environment experiments, is the corrosion current in a real working environment. The metal corrosion dynamics follows the power function law:

[0049] In the formula, Weight loss due to corrosion; is the time when the reaction occurs; It is a constant and is related to the metal material; is the corrosion rate, which is a function of the salt spray concentration c: The specific function form and parameters are related to the metal material used. The corrosion weight loss rate can be obtained by taking the derivative of the above formula for the sample: The relationship between corrosion current and salt spray concentration can be calculated based on the above formula: =

[0050] in, for t Corrosion current at each moment; is the conversion coefficient between corrosion current and corrosion weight loss rate, which is a constant. According to the above formula, the relationship between the reaction time and salt spray concentration in the experimental environment and the actual working environment is:

[0051] The simplification is:

[0052] Experimental environment reaction time and real working condition response time And the actual working condition salt spray concentration Substitute the above formula to calculate the salt spray concentration of the experimental environment size.

[0053] Step 5. Corrosion experiment simulating real working conditions: Based on the oxygen concentration and salt spray concentration of the experimental environment obtained in step 4, as well as the four parameter values ​​of the sample temperature and gas flow rate of the experimental environment, an experimental environment simulating real working conditions is created in the high-speed airflow circulation loop, so that the temperature of the sample in the loop and the flow rate, oxygen concentration and salt spray concentration of the gas in the loop reach the parameter values ​​set in step 4; after the environmental parameters are detected to be stable through the environmental parameter measurement module, the corrosion experiment simulating real working conditions is started to collect the sample corrosion field data.

[0054] Specifically, the salt water concentration in the brine tank is adjusted according to the calculated salt spray concentration parameters. The IRT camera 3 is powered on, the PID controller is powered on, the PID controller target temperature is set, and the electromagnetic induction coil 6 is powered on to begin heating the specimen 5. After the temperature in the region of interest of the specimen 5 is substantially stable, the feed rate of the universal testing machine is adjusted to provide a certain stress state for the specimen 5. The valves of the oxygen-depleted tank 19 and the oxygen-enriched tank 20 are opened, the fan 12 is powered on, the air compressor 17 is powered on, the saturator 15 valve is opened, and a certain concentration of salt spray is introduced into the high-speed airflow circulation loop 13 via the atomizing spray gun 14. Based on the gas flow rate, oxygen concentration requirements, and data measured by the data acquisition card 10, the fan 12 speed is adjusted to adjust the gas flow rate within the high-speed airflow circulation loop 13. The valves of the oxygen-depleted tank 19 and the oxygen-enriched tank 20 are adjusted to adjust the oxygen concentration, so that each parameter is adjusted to the target value. After the experimental environment parameters stabilize, light source 1 is powered on to adjust the field brightness of DIC camera 2. DIC camera 2 is then turned on to capture an image of the corrosion field on the surface of specimen 5, and the cross-sea high-speed aircraft operating condition simulation experiment begins. DIC camera 2 transmits the captured corrosion field image to computer 23 for storage and display.

[0055] During the simulation experiment, the oxygen concentration, gas flow rate, salt spray concentration, gas pressure and other data measured by the data acquisition card 10 are periodically checked to ensure the stability of the experimental parameters.

[0056] Step 6. After completing the experiment in Step 5, turn off all components in the apparatus and remove the specimen. Specifically, turn off the power to the electromagnetic induction coil 6, adjust the universal testing machine feed rate to its initial setting, close the valves of the oxygen-depleted tank 19 and oxygen-enriched tank 20, turn off the power to the air compressor 17, close the valve of the saturator 15, turn off the power to the fan 12, turn off the power to the PID controller, and turn off the power to the IRT camera. Open the latch clamp 28, open the sealed hatch 32, and loosen the chuck 4 of the universal testing machine to remove the specimen 5.

[0057] Step 7. Speckle patterning was performed on the specimen removed from Step 6. The speckle patterning was created using a white, high-temperature-resistant inorganic adhesive and a black ceramic coating. The white adhesive was evenly applied to the specimen surface. After the white base layer solidified, the black ceramic coating was sprayed onto the base layer to form random black speckles. The computer, light source, and DIC camera were turned on. Calibration was completed using a calibration plate and computer 23 (the calibration process involves using the calibration plate to calibrate the specimen position and determine the relative position of the DIC camera and specimen 5 in space). The ends of the speckled specimen were re-clamped between the two chucks of a universal testing machine. The universal testing machine was set to uniformly stretch the specimen. The sampling frequency was set. The DIC camera captured a full-field deformation image of the specimen and transmitted it to computer 23 for processing into displacement and strain field data, completing the specimen mechanical property testing experiment.

[0058] like Figure 6 As shown, Figure 6 The temperature field data collected by the IRT camera during the experiment, as well as the deformation field and corrosion field data collected by the DIC camera. In the figure, the strain field distribution is the vertical strain, horizontal strain and tangential strain measured at the same time, where ε 11 represents the vertical strain, ε 22 represents the horizontal strain, γ 12 represents the xy tangential strain.

[0059] The present invention overcomes the difficulty that existing technologies cannot realize full-state simulation testing of the service working conditions of cross-sea high-speed aircraft, and proposes an experimental test device and experimental method that can realize the coupling of five fields: heat, force, flow, oxygen and salt. The device can realize closed-loop control of the sample temperature over a wide temperature range, the construction of a comprehensive stress state, the construction of a controllable high-speed airflow, and a gas environment with adjustable oxygen concentration and salt spray concentration. It can complete the collection of sample temperature field, deformation field and oxidation corrosion field data during the experiment. The experimental method of the present invention is an equivalent experimental method for reduced-order acceleration of the working conditions of cross-sea high-speed aircraft, which can complete the reduced-order processing of airflow velocity parameters and complete the acceleration of oxidation and salt spray corrosion reactions in the simulation experiment.

[0060] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A thermal flow, oxygen, salt and five-field combined cross-sea high-speed flight simulation working condition experimental test device, characterized in that: include: A high-speed airflow circulation loop is formed by a circular hollow shell, and the shell of the high-speed airflow circulation loop is horizontally fixed on the side column of the universal testing machine; A fan is placed inside the high-speed airflow circulation loop to ensure that the internal airflow flows at a set flow rate; Electromagnetic induction heating module, used to heat the sample located in the high-speed airflow circulation loop; An oxygen supply module is used to introduce a set concentration of oxygen into the high-speed airflow circulation loop; A salt mist generating module is used to introduce salt mist of a set concentration into the high-speed airflow circulation loop; Environmental parameter measurement module, used to monitor gas flow rate, oxygen concentration, gas pressure and salt spray concentration in the high-speed airflow circulation loop; Temperature field measurement module, used to measure the temperature field of the sample in the high-speed airflow circulation loop; Deformation field measurement module, used to measure the deformation image and corrosion field image of the sample in the high-speed airflow circulation loop; and a computer for receiving, displaying and storing the measurement data collected by the environmental parameter measurement module, the temperature field measurement module and the deformation field measurement module, and processing the sample deformation image collected by the deformation field measurement module into displacement field and strain field data; Among them, the experimental section in the high-speed airflow circulation loop is used to install the sample, and the two ends of the sample vertically passing through the experimental section are connected to the corresponding chucks of the universal testing machine.

2. The thermal flow, oxygen, salt and five-field combined cross-sea high-speed flight simulation working condition test device according to claim 1 is characterized in that: The electromagnetic induction heating module includes an electromagnetic induction coil and a PID controller. The electromagnetic induction coil is electrically connected to the PID controller. The electromagnetic induction coil is placed outside the experimental section in the high-speed airflow circulation loop and is placed at a certain distance from the outer shell of the high-speed airflow circulation loop. The electromagnetic induction coil is used to heat the sample in the experimental section, and the PID controller is used to control the heating temperature of the electromagnetic induction coil.

3. The thermal flow, oxygen, salt and five-field combined cross-sea high-speed flight simulation working condition test device according to claim 1 is characterized in that: The oxygen supply module comprises an oxygen-depleted tank and an oxygen-enriched tank, and the gas outlets of the oxygen-depleted tank and the oxygen-enriched tank are both connected to a high-speed airflow circulation loop through pipelines and joints.

4. The thermal flow, oxygen, salt and five-field combined cross-sea high-speed flight simulation working condition test device according to claim 1 is characterized in that: The salt spray generating module includes an atomizing spray gun, a saturator, an oil-water separator, an air compressor and a brine tank, wherein the air compressor is used to compress air, the oil-water separator is used to purify the compressed air, the saturator is used to humidify and heat the purified compressed air, the brine tank is used to store brine, the nozzle of the atomizing spray gun is connected to a high-speed airflow circulation loop, and the atomizing spray gun is used to suck out the brine in the brine tank through negative pressure when the compressed air is sprayed out of the nozzle, and the brine is atomized and sprayed into the high-speed airflow circulation loop.

5. The thermal flow, oxygen, salt and five-field combined cross-sea high-speed flight simulation working condition test device according to claim 1 is characterized in that: The environmental parameter measurement module includes a gas flow rate sensor, an oxygen concentration sensor, a gas pressure sensor, a salt spray concentration sensor and a data acquisition card, wherein the gas flow rate sensor, the oxygen concentration sensor, the gas pressure sensor and the salt spray concentration sensor are all placed in a high-speed airflow circulation loop and are respectively used to sense the flow rate, oxygen concentration, pressure and salt spray concentration of the gas in the loop; the gas flow rate sensor, the oxygen concentration sensor, the gas pressure sensor and the salt spray concentration sensor are all connected to the data acquisition card through lines to feed back collected data to the data acquisition card; the data acquisition card is connected to a computer, and the data acquisition card converts the collected data into signals and transmits them to the computer.

6. The thermal flow, oxygen, salt and five-field combined cross-sea high-speed flight simulation working condition test device according to claim 1 is characterized in that: The temperature field measurement module includes an IRT camera, which is connected to a computer. The IRT camera is used to collect the temperature field of the sample in the high-speed airflow circulation loop and feed the collected data back to the computer.

7. The thermal flow, oxygen, salt and five-field combined cross-sea high-speed flight simulation working condition test device according to claim 1 is characterized in that: The deformation field measurement module includes multiple light sources and multiple DIC cameras. The multiple DIC cameras are all connected to a computer. The light sources are used to provide a lighting environment for the DIC cameras to shoot. The DIC cameras are used to collect sample deformation and corrosion field images of the sample in the high-speed airflow circulation loop during the experiment, and feed the collected images back to the computer.

8. The thermal flow, oxygen, salt and five-field combined cross-sea high-speed flight simulation working condition test device according to claim 1 is characterized in that: A pressure relief valve is installed on the shell of the high-speed airflow circulation loop, and the pressure relief valve is used to adjust the air pressure inside and outside the loop.

9. The thermal flow, oxygen, salt and five-field combined cross-sea high-speed flight simulation working condition test device according to claim 1 is characterized in that: The high-speed airflow circulation loop is provided with a contraction section in the front section adjacent to the experimental section along the airflow direction, and the curve of the contraction section adopts a Vickers curve.

10. A thermal flow, oxygen, salt and five-field combined cross-sea high-speed flight simulation test method, characterized in that: The following steps are involved: Step 1. Sample preparation: The material to be studied is processed into a strip sample with notches symmetrically arranged on both sides of the middle; Step 2. Specimen Installation: Install the specimen vertically in the test section of the high-speed airflow loop, ensuring the notch in the middle of the specimen is located in the vertical center of the test section. Clamp the specimen at its upper and lower ends using the upper and lower chucks of a universal testing machine. Seal the specimen where it exits the housing of the high-speed airflow loop. Step 3. Air tightness check: Check the air tightness of the entire high-speed airflow circulation loop; Step 4. Determine the oxygen concentration and salt spray concentration of the sample test environment: According to the oxygen concentration, gas flow rate and temperature of the actual working environment, the oxygen concentration in the experimental environment is obtained when the gas flow rate and sample temperature are set in the experimental environment; According to the reaction time and corrosion current of the actual working environment, the corrosion current in the experimental environment is obtained under the condition of setting the reaction time of the experimental environment, and then the salt spray concentration is obtained from the corrosion current in the experimental environment; Step 5. Corrosion test simulating real working conditions: Based on the oxygen concentration and salt spray concentration of the experimental environment obtained in step 4, as well as the set four parameter values ​​of the sample temperature and gas flow rate of the experimental environment, an experimental environment is created in the high-speed airflow circulation loop so that the temperature of the sample in the loop and the flow rate, oxygen concentration, and salt spray concentration of the gas in the loop reach the set parameter values; after the environmental parameter measurement module detects that the environmental parameters are stable, a corrosion experiment simulating real working conditions is started to collect sample corrosion field data; Step 6. After the experiment in step 5 is completed, turn off the switches of each component in the device and remove the sample; Step 7. Test the mechanical properties of the specimen: Create speckles on the specimen removed from step 6. Re-clamp the two ends of the speckled specimen to the two chucks of the universal testing machine. Set the universal testing machine to uniformly stretch the specimen, collect the full-field deformation data of the specimen, and complete the mechanical properties test experiment of the specimen.

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