Aircraft test coupon level thermal protection test apparatus and method of testing

Abstract

The application provides a device for thermal protection test of aircraft test sample and a test method thereof. The device is mainly composed of a heating device, a test sample, a shell, a component, a temperature sensor and a fixing clamp. The test sample can be in various forms, such as ceramic matrix composite material, flexible thermal insulation material, metal and thermal protection material. In the early stage of aircraft development, the thermal protection test can be carried out by combining the flat plate with the shell, and the influence of different thermal protection materials, the space gap between the shell and the cabin, the surface radiation coating and the like on the thermal protection performance can be directly obtained.

Description

Technical Field

[0001] This invention relates to the field of thermal protection testing, specifically to a thermal protection testing device and method for aircraft test specimens. Background Technology

[0002] When an aircraft flies at supersonic speeds, its surface is subjected to varying degrees of aerodynamic heating. To ensure flight safety, thermal protection design is necessary to absorb, transfer, or dissipate aerodynamic heat. This design requires ground testing to guide it, primarily wind tunnel testing and simulation of aerodynamic heating environments. In the early stages of aircraft development, it is not feasible to conduct thermal protection tests on components or the entire aircraft. Even in the mid-stage of development, directly conducting thermal protection tests on components or the entire aircraft is costly. Thermal protection tests are usually performed on test specimens. To simulate the heating of the aircraft's outer surface during flight, only the outer surface of the test specimen is heated during the test. The thermal load is measured by temperature or heat flow sensors, amplified, and fed back to the controller. The controller then corrects, adjusts, and outputs a signal to the heating device to ensure that the heating load is within the allowable tolerance range of the target load. The back temperature of the plate is measured, and tests are conducted on combinations of the substrate with different thermal insulation / ablation materials to compare the thermal insulation performance of the thermal protection materials.

[0003] Thermal protection design must ensure that the missile structure meets the strength and stiffness requirements under static thermal loads while ensuring that the cabin components can function normally in the high-temperature environment caused by aerodynamic heat. The components are generally encapsulated in a shell and connected to the aircraft cabin section. Traditional experimental sample-level thermal protection tests only obtain the back temperature of the thermal protection plate, which can obtain the thermal insulation performance of different protective materials. The back temperature of the plate can be equivalent to the internal wall temperature of the cabin. In actual flight, the heat load will be transferred to the component and equipment shell through conduction, convection and radiation, and further transferred to the components. The measured back temperature results can correct the material thermal parameters, but the cabin environment still needs finite element simulation analysis. The back temperature results of the plate cannot be conveniently and effectively used as input for thermal protection design. Summary of the Invention

[0004] To address the problems of existing technologies, this invention provides a thermal protection test device and method for aircraft test specimens. In the early stages of aircraft development, thermal protection tests can be conducted by combining a flat plate with the component shell, allowing for a direct observation of the impact of different thermal protection materials, the spatial gap between the component shell and the compartment, and surface radiation coatings on thermal protection performance.

[0005] This invention provides a thermal protection testing device for aircraft test specimens, comprising a heating device, a test specimen, and a simulated component housing arranged sequentially. The test specimen includes a fixedly connected metal plate and an inner heat insulation material. The heating device faces the metal plate, and the heating side of the metal plate is perpendicular to the direction of the heat flow applied by the heating device. An adjustment pad is provided between the inner heat insulation material and the simulated component housing. The simulated component housing has a thin-walled structure, and a component is fixed inside the simulated component housing. A sealing flexible heat insulation material is arranged around the gap between the test specimen and the simulated component housing. A fixed heat insulation material is provided outside the sealing flexible heat insulation material, and the fixed heat insulation material has a step on the side where the heat load is applied. A heat flux density sensor is installed inside the hole and the stepped hole; a fixing clamp is set on the outside of the fixed insulation material, and the rear end of the fixing clamp is sealed by the insulation material and the sealing cover plate; a temperature sensor for measuring temperature load is arranged on the outer surface of the metal plate, and a number of temperature sensors for measuring the back temperature of the test sample are distributed on the outer surface of the insulation material; a number of temperature sensors for measuring the heat load transferred from the test sample to the shell of the assembled part are distributed inside the simulated part of the assembled part; a set of temperature sensors is distributed on the side of the assembled part closer to the test sample, and another set of temperature sensors is distributed on the side farther from the test sample. The two sets of temperature sensors on both sides of the assembled part are arranged at equal intervals on the same horizontal plane to obtain the temperature gradient of the assembled part.

[0006] Further improvements include adjusting the material of the pad and the metal plate, and using the test device to simulate the heat conduction between the metal plate and the assembled housing.

[0007] In a further improvement, the material of the adjusting pad is the same as that of the inner insulation material, and the test device is used to simulate the heat transfer of the insulation material to the simulated shell of the component through convection and radiation.

[0008] In a further improvement, the spacer blocks are arranged at the four corners of the metal plate.

[0009] In a further improvement, the simulated component housing consists of a housing and a rear cover of the simulated component housing. A lead wire hole is opened in the middle of the rear cover of the simulated component housing, and the temperature sensor cable inside the simulated component housing is led out from the lead wire hole. The rear side of the stepped hole has an L-shaped structure for leading out the heat flux density sensor cable. The heat insulation material and the sealing cover plate have round holes for leading out the temperature sensor cable.

[0010] In a further improvement, the sealing flexible thermal insulation material is a thermal insulation felt or a reinforced fiber aerogel.

[0011] In a further improvement, the component is a temperature-sensitive element, including a circuit board.

[0012] In a further improvement, the fixed heat insulation material is a high-temperature resistant heat insulation brick.

[0013] The present invention also provides a test method for an aircraft test specimen-level thermal protection test device, comprising the following steps:

[0014] 1) Prepare multiple sets of test samples, with different thicknesses and materials for the metal plate and internal insulation material;

[0015] 2) Fabricate a prototype housing, assemble the test sample and the prototype housing together, and arrange the sensors;

[0016] 3) The test sample is heated by heating equipment, and the temperature load is measured by temperature sensor or heat flux density sensor and fed back to the control system to realize the application of thermal load;

[0017] 4) The internal insulation material transfers the thermal load to the component housing simulation component, and the sensors inside the component housing simulation component obtain the thermal load transferred to the component housing simulation component; the temperature sensor arranged on one side surface of the component measures the thermal load transferred from the component housing simulation component to the component.

[0018] The beneficial effects of this invention are as follows:

[0019] 1. In the early stages of aircraft development, the back temperature of the test sample can be directly measured to obtain its thermal protection performance;

[0020] 2. It can simulate the gap between the test specimen and the finished product housing, measure the heat transferred from the test specimen to the finished product housing, and obtain the thermal load of the finished product inside the housing, providing direct and effective data for thermal simulation and thermal protection design. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of a thermal protection test.

[0023] Figure 2 This is a front view of the test sample and the adjustment pad.

[0024] Figure 3 Left view of the test sample and adjustment pad;

[0025] Figure 4 Right view of the test sample and adjusting pad;

[0026] Figure 5 Left view of the housing of the simulated component;

[0027] Figure 6Right view of the housing of the simulated component;

[0028] Figure 7 Right view of the housing of the simulated component;

[0029] Figure 8 Left view of the rear cover of the assembled simulation part;

[0030] Figure 9 Left view of the fixed insulation material;

[0031] Figure 10 This is a cross-sectional view of the fixed thermal insulation material.

[0032] In the diagram, 1 is the heating device, 2 is the metal plate, 3 is the thermal insulation material, 4 is the adjusting pad, 5 is the housing simulation component, 6 is the circuit board, 7 is the connecting screw, 8 is the back cover of the housing simulation component, 9 is the sealing flexible thermal insulation material, 10 is the adjusting flexible thermal insulation material, 11 is the fixing thermal insulation material, 12 is the fixing clamp, 13 is the thermal insulation material, 14 is the clamp sealing cover plate, 15 is the countersunk screw, 16 is the temperature sensor A, 17 is the through hole, 18 is the temperature sensor B, 19 is the temperature sensor C, 20 is the temperature sensor D, 21 is the temperature sensor E, 22 is the temperature sensor F, 23 is the connecting hole, 24 is the temperature sensor BB, 25 is the temperature sensor CC, 26 is the temperature sensor DD, 27 is the circuit board mounting boss, 28 is the temperature sensor EE, 29 is the temperature sensor FF, 30 is the temperature sensor G, 31 is the temperature sensor H, 32 is the temperature sensor I, 33 is the temperature sensor J, 34 is the temperature sensor K, 35 is the lead wire round hole, and 36 is the lead wire bend. Detailed Implementation

[0033] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] A thermal protection test device for aircraft prototypes is used to conduct thermal protection tests, such as... Figure 1 As shown, the test device mainly consists of heating equipment 1, test sample, adjusting pad 4, complete housing simulation part 5, complete part, complete simulation part back cover 8, sealing flexible heat insulation material 9, adjusting flexible heat insulation material 10, fixing heat insulation material 11, heat insulation material 13, fixing clamp 12, clamp sealing cover plate 14, countersunk screw 15, temperature sensor, etc.

[0035] The test specimen described can have various structural forms. The test specimen in this paper consists of a metal plate 2 and an internal thermal insulation material 3, and an example is provided.

[0036] The components described are temperature-sensitive and can take various structural forms. This article uses circuit board 6 as an example.

[0037] Temperature sensor A16 is arranged on metal plate 2; temperature sensor B18, temperature sensor C19, temperature sensor D20, temperature sensor E21, and temperature sensor F22 are arranged on inner insulation material 3; temperature sensor BB24, temperature sensor CC25, temperature sensor DD26, temperature sensor EE28, and temperature sensor FF29 are arranged on component housing simulation component 5; temperature sensor G30, temperature sensor H31, temperature sensor I32, temperature sensor J33, and temperature sensor K34 are arranged on circuit board 6.

[0038] Heating device 1 is arranged on one side of the test sample. The test sample consists of a metal plate 2 and an inner heat insulation material 3. According to the implementation process, the heat insulation material 3 is connected and fixed to the metal plate 2, and the inner heat insulation material is located inside the metal plate.

[0039] An adjusting pad 4 is designed between the test sample and the simulated shell 5. The thickness of the adjusting pad 4 is adjustable and is used to simulate the gap between the thermal insulation material 3 and the simulated shell 5. The material of the adjusting pad 4 can be the same as the material of the metal plate 2 or the same as the inner thermal insulation material. When the material of the adjusting pad 4 is the same as the material of the metal plate 2, it simulates the heat conduction between the metal plate 2 and the simulated shell 5. When the material of the adjusting pad 4 is the same as the material of the inner thermal insulation material 3, it mainly simulates the heat transfer of the thermal insulation material 3 to the simulated shell 5 through convection and radiation. The adjusting pad 4 is arranged at the four corners of the metal plate 2.

[0040] The simulated housing 5 is a thin-walled structure, made of the same material as the actual housing. To reduce its heat capacity, the simulated housing 5's thickness is set to the lower limit of the actual housing's thickness tolerance. The simulated housing is internally mounted. This description uses circuit board 6 as an example; circuit board 6 is fixed to the simulated housing 5 using connecting screws 7. Circuit board 6 is connected and fixed to the simulated housing 5 according to the actual connection method. The simulated housing's rear cover 8 is mounted and fixed to the simulated housing 5. The rear cover 8 has a lead wire hole 35 in the center, through which the temperature sensor cable inside the simulated housing 5 is led out.

[0041] To reduce heat exchange between the air in the gap between the test sample and the simulated housing 5 and the external flowing air, a sealing flexible thermal insulation material 9 is arranged around the gap between the test sample and the simulated housing 5. This material can be thermal insulation felt or reinforced fiber aerogel. An adjustable flexible thermal insulation material 10 is installed at the rear bottom of the simulated housing 5 to ensure that the simulated housing 5 is in a horizontal state, and that the heating side of the metal plate 2 is perpendicular to the direction of the applied heat flow, ensuring that the heat load is uniformly applied to the metal plate 2. The outer side of the sealing flexible thermal insulation material 9 is a fixed thermal insulation material 11, which can be a high-temperature resistant thermal insulation brick. The fixed thermal insulation material 11 has a stepped hole 36 on the side where the heat load is applied. The stepped hole 36 is used to install a heat flux density sensor. The rear side of the stepped hole 36 has an L-shaped structure for leading out the heat flux density sensor cable. The outer side of the fixed thermal insulation material 11 is a fixing clamp 12. The thermal insulation material 13 is installed on the clamp sealing cover plate 14. The fixing clamp 12 and the sealing cover plate 14 form a fixing clamp. The thermal insulation material 13 and the sealing cover plate 14 have round holes. These round holes have the same function as the lead wire round hole 35 of the rear cover 8 of the finished simulation part, and are used to lead out the temperature sensor cable.

[0042] Temperature sensor A16 is positioned on the outer side of the test sample, i.e., the outer surface of the metal plate 2, and feeds the measured temperature load back to the control system. A heat flux sensor is positioned at the stepped hole location on the plane of the outer surface of the test sample, simultaneously measuring the heat flux density load, which can be used to feed back to the control system. Temperature sensors B18, C19, D20, E21, and F22 are positioned on the inner side of the test sample, i.e., the outer surface of the insulation material 3, measuring the back temperature of the test sample and directly obtaining the insulation performance of the insulation material. Temperature sensors BB24, CC25, and DD26... Sensors EE28 and FF29 are arranged inside the component housing simulation component 5. Their numbers and relative spatial positions correspond one-to-one with the sensors on the test sample to obtain the thermal load transferred from the test sample to the component housing simulation component 5. Temperature sensors are arranged on the component circuit board 6 inside the component housing simulation component 5. Temperature sensors G30, H31, and I32 are arranged at equal intervals on one side of the test sample, and temperature sensors J33 and K34 are arranged in the direction away from the test sample. Temperature sensors J33, K34, and H31 are arranged at equal intervals on the same horizontal plane to obtain the temperature gradient on the circuit board 6.

[0043] The specific test method using this test apparatus is as follows:

[0044] 1) Prepare multiple sets of test samples, with different thicknesses and materials for the metal plate and internal insulation material;

[0045] 2) Fabricate a prototype housing, assemble the test sample and the prototype housing together, and arrange the sensors;

[0046] 3) The test sample is heated by heating equipment, and the temperature load is measured by temperature sensor or heat flux density sensor and fed back to the control system to realize the application of thermal load;

[0047] 4) The internal insulation material transfers the thermal load to the component housing simulation component, and the sensors inside the component housing simulation component obtain the thermal load transferred to the component housing simulation component; the temperature sensor arranged on one side surface of the component measures the thermal load transferred from the component housing simulation component to the component.

[0048] The various embodiments in this specification are described in a progressive manner. Similar or identical parts between embodiments can be referred to interchangeably. Each embodiment focuses on its differences from other embodiments. In particular, for the device embodiments, the above descriptions are merely preferred embodiments of the present invention. Since they are fundamentally similar to the method embodiments, the descriptions are relatively simple, and relevant parts can be referred to the descriptions of the method embodiments. The above descriptions are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention, without departing from the principle of the present invention, should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A thermal protection test device for aircraft test specimens, characterized in that: The system includes a heating device, a test sample, and a simulated component housing, arranged sequentially. The test sample comprises a fixedly connected metal plate and an inner insulating material. The heating device faces the metal plate, and the heating side of the metal plate is perpendicular to the direction of the heat flow applied by the heating device. An adjusting pad is provided between the inner insulating material and the simulated component housing. The simulated component housing has a thin-walled structure, and a component is fixed inside the simulated component housing. A sealing flexible insulating material is arranged around the gap between the test sample and the simulated component housing. A fixed insulating material is provided on the outside of the sealing flexible insulating material. The fixed insulating material has a stepped hole on the side where the heat load is applied, and a heat flow meter is installed in the stepped hole. Temperature sensors are used; a fixing clamp is provided on the outside of the fixed heat insulation material, and the rear end of the fixing clamp is sealed by the heat insulation material and the sealing cover plate; temperature sensors for measuring temperature load are arranged on the outer surface of the metal plate, and several temperature sensors for measuring the back temperature of the test sample are distributed on the outer surface of the heat insulation material; several temperature sensors for measuring the heat load transferred from the test sample to the shell of the assembled component are distributed inside the assembled component housing; a set of temperature sensors is distributed on the side of the assembled component closer to the test sample, and another set of temperature sensors is distributed on the side farther from the test sample. The two sets of temperature sensors on both sides of the assembled component are arranged at equal intervals on the same horizontal plane to obtain the temperature gradient of the assembled component.

2. The aircraft test article level thermal protection test apparatus of Claim 1, wherein: The adjusting pad is made of the same material as the metal plate, and the test device is used to simulate the heat conduction between the metal plate and the assembled shell simulation component.

3. The aircraft test article level thermal protection test apparatus of Claim 1, wherein: The material of the adjusting pad is the same as that of the inner insulation material. The test device is used to simulate the heat transfer of the insulation material to the simulated shell component through convection and radiation.

4. The aircraft test specimen-level thermal protection test device according to claim 2 or 3, characterized in that: The spacer blocks are arranged at the four corners of the metal plate.

5. The aircraft test specimen-level thermal protection test device according to claim 1, characterized in that: The simulated component housing consists of a housing and a rear cover. The rear cover has a lead wire hole in the middle, through which the temperature sensor cable inside the simulated component housing is led out. The back of the stepped hole has an L-shaped structure for leading out the heat flux density sensor cable. The insulation material and the sealing cover have holes for leading out the temperature sensor cable.

6. The aircraft test article level thermal protection test device of Claim 1, wherein: The sealing flexible thermal insulation material is thermal insulation felt or reinforced fiber aerogel.

7. The aircraft test specimen-level thermal protection test device according to claim 1, characterized in that: The component is a circuit board.

8. The aircraft test specimen-level thermal protection test device according to claim 1, characterized in that: The fixed heat insulation material is a high-temperature resistant heat insulation brick.

9. A test method for an aircraft test specimen-level thermal protection test device, employing the aircraft test specimen-level thermal protection test device as described in any one of claims 1-8, characterized in that... Includes the following steps: 1) Prepare multiple sets of test samples, with different thicknesses and materials for the metal plate and internal insulation material; 2) Fabricate a prototype housing, assemble the test sample and the prototype housing together, and arrange the sensors; 3) The test sample is heated by heating equipment, and the temperature load is measured by temperature sensor or heat flux density sensor and fed back to the control system to realize the application of thermal load; 4) The internal insulation material transfers the thermal load to the component housing simulation component, and the sensors inside the component housing simulation component obtain the thermal load transferred to the component housing simulation component; the temperature sensor arranged on one side surface of the component measures the thermal load transferred from the component housing simulation component to the component.

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