Temperature measurement device for heat protection layer of aircraft and thickness design method

Abstract

The present application discloses a temperature measurement device and a thickness design method for the thermal protection layer of an aircraft, relating to the technical field of aircraft testing. The temperature measurement device includes a measurement component that penetrates the load-bearing shell and the thermal protection layer, and the outer end face of the measurement component is flush with the outer surface of the thermal protection layer. A number of thermocouple wires for measuring temperature are arranged inside the measurement component. The thermocouple wires are parallel to the outer end face of the measurement component, and the distances of each thermocouple wire from the outer end face of the measurement component are different. The material of the measurement component is the same as that of the thermal protection layer. The temperature measurement device and the thickness design method of the present application are not only applicable to high heat flux situations, but also can avoid the occurrence of cold spot effects.

Description

Technical Field

[0001] The present application relates to the technical field of aircraft testing, and particularly relates to a temperature measuring device and a thickness design method for the heat insulation layer of an aircraft. Background Art

[0002] With the development of aircraft towards hypersonic, long endurance, near space and maneuverable flight directions, the aerodynamic heating problem faced by aircraft is becoming more and more serious. A conservative thermal protection design, which thickens the thermal insulation layer as much as possible on the outer surface of the aircraft, results in a large redundant mass and a small payload of the aircraft, affecting the overall performance of the aircraft; while an aggressive thermal protection design, which thins the thermal insulation layer as much as possible, may lead to the damage of the thermal protection structure during flight, resulting in flight failure. Therefore, it is crucial to carry out a proper thermal protection design. As an important parameter of the aircraft thermal environment, heat flux is the key to affecting the thermal protection design, which affects the selection of heat insulation materials, the thickness of the heat insulation layer, etc.

[0003] In related technologies, the acquisition of heat flux mainly relies on experimental testing methods, which mainly include ground test methods and flight test methods. Among them, the ground test method generally uses a shock tunnel to simulate flight similarity parameters and measures the heat flux by installing a heat flux meter on the model. However, due to the limitations of ground equipment capabilities, the ground test cannot fully reflect the actual flight situation, and some parameters cannot be simulated accurately, so the results of the ground test are prone to distortion. The data measured by the flight test method is true and effective. It uses a heat flux sensor or a heat flux identification device for measurement. Commonly used heat flux sensors generally use copper as the sensitive element and determine the heat flux by measuring the temperature change in a short period of time. However, for some high heat flux situations, when the temperature exceeds the melting point of the material, this type of sensor is not applicable; more importantly, using high thermal conductivity materials such as copper will cause a large difference in temperature between the sensor and its surrounding area, forming a low temperature area relative to the high temperature area of the nearby heat insulation layer, which is called the cold point effect, thus affecting the heat flux distribution on the surface of the heat insulation layer and failing to achieve the purpose of accurately measuring the heat flux on the surface of the heat insulation layer. Summary of the Invention

[0004] Aiming at the defects existing in the prior art, the purpose of the present application is to provide a temperature measuring device and a thickness design method for the heat insulation layer of an aircraft, which are not only applicable to high heat flux situations, but also can avoid the occurrence of the cold point effect.

[0005] To achieve the above objectives, the technical solution adopted is: a temperature measuring device for an aircraft thermal insulation layer, the temperature measuring device comprising a measuring component, the measuring component penetrating the load-bearing shell and the thermal insulation layer, and the outer end face of the measuring component flush with the outer surface of the thermal insulation layer; a plurality of thermocouple wires for measuring temperature are arranged inside the measuring component, the thermocouple wires are parallel to the outer end face of the measuring component, and the distance between each thermocouple wire and the outer end face of the measuring component is different; the material of the measuring component is the same as that of the thermal insulation layer.

[0006] Based on the above technical solution, the measuring component includes a measuring core and a protective cover. The protective cover passes through the load-bearing shell and the heat-proof layer. The protective cover is interference-fitted with the heat-proof layer, and a certain margin gap is reserved between the circumferential surface of the protective cover and the load-bearing shell; the measuring core is interference-fitted in the center of the protective cover; and the thermocouple wire is passed through the measuring core.

[0007] On the basis of the above technical solution, the outermost thermocouple wire among the plurality of thermocouple wires is at a set distance from the outer end surface of the measuring core, and the remaining thermocouple wires are arranged at equal intervals from the outside to the inside.

[0008] On the basis of the above technical solution, the measuring core is provided with a plurality of radial penetration holes for accommodating thermocouple wires, and the sensitive parts of the thermocouple wires are located in the longitudinal center of the radial penetration holes.

[0009] Based on the above technical solution, the diameter of the radial through hole is larger than the diameter of the thermocouple wire, and the remaining space in the radial through hole after the thermocouple wire is installed is filled with resin.

[0010] On the basis of the above technical solution, the temperature measuring device further includes a clamping cover plate, which is fixed to the inner surface of the load-bearing shell by a set screw, and the clamping cover plate is tightly attached to the inner end face of the measuring core; a lead hole is opened in the center of the clamping cover plate; the measuring core has a wire collecting groove connected to its inner end face at both ends of the radial penetration hole, and the two ends of the measuring core are led out to the inner end face through the wire collecting groove and pass through the lead hole.

[0011] The present application also discloses a thickness design method based on the above-mentioned temperature measuring device, comprising the following steps:

[0012] Mounting holes are opened in the load-bearing shell and the heat-proof layer; at the same time, a plurality of thermocouple wires are installed inside the measuring component, and the thermocouple wires are parallel to the outer end surface of the measuring component; the heat-proof layer has a designed thickness;

[0013] The aircraft is undergoing flight tests, and the thermocouple wire measures the temperature data during flight;

[0014] The surface heat flux is calculated using an inversion algorithm based on the temperature data, and the calculated surface heat flux is compared with the predicted value of the surface heat flux. The design thickness of the thermal protection layer is thickened or thinned based on the analysis results.

[0015] Based on the above technical solution, the measuring component includes a measuring core and a protective cover. The protective cover passes through the load-bearing shell and the heat-proof layer. The protective cover is interference-fitted with the heat-proof layer, and a certain margin gap is reserved between the circumferential surface of the protective cover and the load-bearing shell; the measuring core is interference-fitted in the center of the protective cover; and the thermocouple wire is passed through the measuring core.

[0016] Based on the above technical solution, the measuring core is provided with a plurality of radial through holes for accommodating thermocouple wires, and the sensitive part of the thermocouple wires is located in the center of the length direction of the radial through holes; the diameter of the radial through holes is larger than the diameter of the thermocouple wires, and the remaining gaps in the radial through holes after the thermocouple wires are installed are filled with resin.

[0017] On the basis of the above technical solution, the temperature measuring device further includes a clamping cover plate, which is fixed to the inner surface of the load-bearing shell by a set screw, and the clamping cover plate is tightly attached to the inner end face of the measuring core; a lead hole is opened in the center of the clamping cover plate; the measuring core has a wire collecting groove connected to its inner end face at both ends of the radial penetration hole, and the two ends of the measuring core are led out to the inner end face through the wire collecting groove and pass through the lead hole.

[0018] The beneficial effects of the technical solution provided by this application include:

[0019] 1. The temperature measurement device of the present application is applied to a flight test method. The outer end face of the measuring component is flush with the outer surface of the heat shield, and the material of the measuring component is the same as that of the heat shield. The temperature measurement device of the present application can be applied to high heat flux without worrying about material melting. At the same time, the same material and flat outer surface can effectively avoid the cold spot effect, forming a stable and balanced heat flux distribution on the outer surface of the measuring component and the heat shield. The measurement structure is accurate and can effectively assist in the completion of the heat shield design. The temperature measurement device of the present application can obtain temperature data at different depths of the heat shield during flight, identify the heat flux on the aircraft surface based on the measured temperature data, and use it to guide and correct the design of the heat shield.

[0020] 2. The temperature measurement method of the present application uses a measurement component made of the same material as the heat insulation layer. The measurement component is in the shape of a cylindrical plug and is tightly inserted into the heat insulation layer and the load-bearing shell. The thermocouple wires are arranged at different positions along the depth direction. According to the measured temperature history during flight, the surface heat flux is obtained by inverse calculation. This temperature measurement method avoids the cold point effect and the problem of structural heat matching existing in traditional heat flux meters. At the same time, it can also accurately measure the temperature distribution along the wall thickness direction of the heat insulation layer, which is of great significance for the real heat transfer under ablation and thermophysical and chemical effects. It can effectively promote the refinement of thermal protection design, design a heat insulation layer with appropriate thickness, promote the weight reduction and optimization of the heat insulation layer, and improve the overall performance of the aircraft. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0022] Figure 1 Schematic cross-sectional view of the installed temperature measurement device provided by the embodiment of the present application;

[0023] Figure 2 Schematic partial cut-away view of the temperature measurement device provided by the embodiment of the present application installed in the aircraft cabin section;

[0024] Figure 3 Schematic structural view of the measurement core provided by the embodiment of the present application;

[0025] Figure 4 For Figure 3 Cross-sectional view;

[0026] Figure 5 Comparison diagram of the measured time-temperature curve and the predicted time-temperature curve of five thermocouple wires provided by the embodiment of the present application;

[0027] Reference numerals: 1, measurement core; 2, protective sleeve; 3, heat insulation layer; 4, load-bearing shell; 5, pressing cover plate; 6, heat matching layer; 7, set screw; 8, thermocouple wire; 11, radial through hole; 12, wire collecting groove; 51, lead hole. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0028] In order to make the objectives, technical solutions and advantages of the present application more clear and understandable, the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0029] As Figure 1 shown, an embodiment of a temperature measurement device for the thermal protection layer of an aircraft is disclosed in the present application. The temperature measurement device includes a measurement component. The measurement component penetrates through the load-bearing shell 4 and the thermal protection layer 3, and the outer end face of the measurement component is flush with the outer surface of the thermal protection layer 3; several thermocouple wires 8 for measuring temperature are arranged inside the measurement component, and the thermocouple wires 8 are parallel to the outer end face of the measurement component. The dimensions of each thermocouple wire 8 from the outer end face of the measurement component are different. The material of the measurement component is the same as that of the thermal protection layer 3.

[0030] The temperature measurement device of the present application is applied to a flight test method. The outer end face of the measurement component is flush with the outer surface of the thermal protection layer 3, and the material of the measurement component is the same as that of the thermal protection layer 3. The temperature measurement device of the present application can be applied to high heat fluxes without worrying about the situation of material melting. At the same time, the same material and the flat outer surface can effectively avoid the cold point effect, form a stable and balanced heat flux distribution on the outer surface of the measurement component and the thermal protection layer 3, the measurement structure is accurate, and it can effectively assist in completing the design of the thermal protection layer.

[0031] The temperature measurement device of the present application can obtain the temperature data at different depths of the thermal protection layer 3 during flight, identify the surface heat flux of the aircraft according to the measured temperature data, and be used to guide and correct the design of the thermal protection layer 3.

[0032] In one embodiment, the measurement component includes a measurement core 1 and a protective sleeve 2. The protective sleeve 2 penetrates through the load-bearing shell 4 and the thermal protection layer 3. The protective sleeve 2 is in interference fit with the thermal protection layer 3, and a certain margin gap is reserved between the circumferential surface of the protective sleeve 2 and the load-bearing shell 4; the measurement core 1 is inserted through the center of the protective sleeve 2 in an interference fit; the thermocouple wires 8 are inserted through the measurement core 1.

[0033] The temperature measurement device of the present application focuses on fine structures. The protective sleeve 2 is in interference fit with the thermal protection layer 3, and the measurement core 1 is inserted through the center of the protective sleeve 2 in an interference fit, eliminating possible voids and facilitating the formation of a balanced heat flux. At the same time, the thermal protection layer 3 of the aircraft will undergo thermal deformation under the action of aerodynamic heating during long-term hypersonic flight, and misalignment may occur between the thermal protection layer 3 and the load-bearing shell 4. A certain margin gap is reserved between the circumferential surface of the protective sleeve 2 and the load-bearing shell 4, which can prevent the misalignment from squeezing and damaging the measurement component, ensuring that the measurement component will not be squeezed and collided with the load-bearing shell 4 when moving with the thermal protection layer 3, and improving the safety performance.

[0034] In one embodiment, the outermost thermocouple wire 8 among a plurality of thermocouple wires 8 is at a set distance from the outer end face of the measurement core 1. At this set distance, the thermocouple wire 8 can effectively measure the temperature and will not be exposed due to aerodynamic friction during the high-speed flight of the aircraft. The remaining thermocouple wires 8 are arranged at equal intervals from the outside to the inside, enabling high-quality temperature measurement.

[0035] Preferably, the number of thermocouple wires 8 is five, the set distance is 3 mm, and the distances between the remaining thermocouple wires 8 and the outer end face of the measurement core 1 are 5 mm, 7 mm, 9 mm, and 11 mm respectively.

[0036] In one embodiment, the measurement core 1 is provided with a plurality of radially penetrating holes 11 for accommodating the thermocouple wires 8, and the sensitive parts of the thermocouple wires 8 are located at the center of the length direction of the radially penetrating holes 11. Specifically, the thermocouple wire 8 is a K-type thermocouple wire, and the K-type thermocouple wire has two wires, and the two wires are partially wound into a sensitive part. The remaining parts of the thermocouple wire 8 respectively pass through the two ends of the radially penetrating hole 11.

[0037] Furthermore, the diameter of the radially penetrating hole 11 is larger than the diameter of the thermocouple wire 8, and the remaining voids after installing the thermocouple wire 8 in the radially penetrating hole 11 are filled with resin. Specifically, the diameter of the radially penetrating hole 11 is 1 mm, while the diameter of the thermocouple wire 8 is 0.5 mm. In the temperature measurement device of the present application, filling resin in the radially penetrating hole 11 avoids the shaking of the thermocouple wire 8 in the radially penetrating hole 11, ensuring the measurement stability; and the resin is the same as the component resin of the heat insulation layer 3 (a component material of the heat insulation layer 3), that is, the same as the component resin of the protective sleeve 2, making the material compatibility between the measurement core 1 and the protective sleeve 2 strong and the connection reliability good.

[0038] In one embodiment, the temperature measurement device further includes a pressing cover plate 5. The pressing cover plate 5 is fixed to the inner surface of the load-bearing housing 4 by a set screw 7, and the pressing cover plate 5 is closely attached to the inner end face of the measurement core 1. The pressing cover plate 5 presses the measurement assembly in the installation holes of the load-bearing housing 4 and the heat insulation layer 3. A lead hole 51 is opened in the center of the pressing cover plate 5; the measurement core 1 is provided with wire collecting grooves 12 communicating with its inner end face at both ends of the radially penetrating hole 11. The two ends of the measurement core 1 are led out to the inner end face through the wire collecting grooves 12 and pass through the lead hole 51, and are connected to a data acquisition device after passing through. The radially penetrating hole 11 is arranged radially, and the wire collecting groove 12 is arranged axially. The pressing cover plate 5 of the present application further strengthens the connection stability.

[0039] Specifically, the protective sleeve 2 includes a large-diameter cylinder and a medium-diameter cylinder, and the measuring core 1 includes a large-diameter cylinder and a small-diameter cylinder. The large-diameter cylinders of the protective sleeve 2 and the measuring core 1 have the same dimensions. The small-diameter cylinder of the measuring core 1 penetrates through the large-diameter cylinder and the medium-diameter cylinder of the protective sleeve 2. The large-diameter cylinder of the measuring core 1 is in close contact with the large-diameter cylinder of the protective sleeve 2, and the pressing cover plate 5 is in close contact with the large-diameter cylinder of the measuring core 1.

[0040] Preferably, a thermal matching layer 6 is further provided between the thermal insulation layer 3 and the load-bearing housing 4 for further heat insulation.

[0041] The present application also discloses a temperature measurement method based on the above temperature measurement device, including the following steps:

[0042] Installation holes are opened in the load-bearing housing 4 and the thermal insulation layer 3, and these installation holes are used to install the temperature measurement device. At the same time, a plurality of thermocouple wires 8 are installed inside the measurement component, and the thermocouple wires 8 are parallel to the outer end face of the measurement component; the thermal insulation layer 3 has a designed thickness.

[0043] The aircraft conducts a flight test, and the thermocouple wires 8 measure the temperature data during flight and feedback it to the data acquisition device. Specifically, the thermocouple wires 8 extend inward after passing through both ends of the radial through-hole 11 and are connected to the data acquisition device.

[0044] The surface heat flux is calculated using an inversion algorithm based on the temperature data, and the calculated surface heat flux is compared and analyzed with the predicted value of the surface heat flux. The thermal insulation layer is thickened or thinned based on the designed thickness. The data analysis device performs inversion algorithm calculation and analysis based on the data obtained from the data acquisition device. Specifically, there are already mature calculation cases of the inversion algorithm in the country.

[0045] The temperature measurement method of the present application uses a measurement component made of the same material as the thermal insulation layer 3. The measurement component is in the shape of a cylindrical plug and is tightly plugged between the thermal insulation layer 3 and the load-bearing housing. The thermocouple wires 8 are arranged at different positions along the depth direction. According to the measured temperature history during flight, the surface heat flux is obtained by using inversion calculation; this temperature measurement method avoids the cold point effect and the structural thermal matching problem existing in traditional heat flux meters. At the same time, it can also accurately measure the temperature distribution along the wall thickness direction of the thermal insulation layer 3, which is of great significance for the real heat transfer under the action of ablation and thermophysical and chemical effects. It can effectively promote the refinement degree of thermal protection design, design a thermal insulation layer 3 with appropriate thickness, promote the weight reduction and optimization of the thermal insulation layer 3, and improve the overall performance of the aircraft.

[0046] In one embodiment, the comparison graph of the measured time-temperature curve and the predicted time-temperature curve of five thermocouple wires is shown in Figure 5By comparing and analyzing the two curves, it is found that the heat protection layer design has a certain margin. Comprehensive evaluation (the rules of comprehensive evaluation are not introduced in detail in this application) shows that the heat protection layer can be thinned by 2-3mm.

[0047] Regarding the temperature measurement method, in one embodiment, the measuring component includes a measuring core 1 and a protective cover 2, the protective cover 2 passes through the load-bearing shell 4 and the heat-proof layer 3, the protective cover 2 is interference fit in the heat-proof layer 3, and a certain margin gap is reserved between the circumferential surface of the protective cover 2 and the load-bearing shell 4; the measuring core 1 is interference-pierced in the center of the protective cover 2; the thermocouple wire 8 is passed through the measuring core 1.

[0048] In the temperature measurement method of this application, the protective cover 2 has an interference fit with the heat shield 3, and the measuring core 1 is interference-threaded through the center of the protective cover 2, eliminating any potential gaps and facilitating a balanced heat flow. Furthermore, during prolonged hypersonic flight, the aircraft's heat shield 3 will thermally deform due to aerodynamic heating, potentially causing misalignment between the heat shield 3 and the load-bearing shell 4. A certain margin of clearance is reserved between the circumferential surface of the protective cover 2 and the load-bearing shell 4 to prevent this misalignment from damaging the measuring assembly and ensure that the measuring assembly will not be squeezed or collided with the load-bearing shell 4 as it moves with the heat shield 3, thereby improving safety.

[0049] Regarding the temperature measurement method, in one embodiment, the outermost thermocouple wire 8 of the plurality of thermocouple wires 8 is positioned a predetermined distance from the outer end surface of the measuring core 1. This predetermined distance allows for effective temperature measurement while preventing exposure to aerodynamic friction during high-speed flight. The remaining thermocouple wires 8 are arranged evenly spaced from the outside to the inside, ensuring high-quality temperature measurement.

[0050] Regarding the temperature measurement method, in one embodiment, the measuring core 1 is provided with a plurality of radial through-holes 11 for accommodating thermocouple wires 8 , with the sensitive portion of the thermocouple wires 8 located at the longitudinal center of the radial through-holes 11. Specifically, the thermocouple wires 8 are K-type thermocouple wires, which have two wires partially twisted to form the sensitive portion. The remaining portions of the thermocouple wires 8 extend through the ends of the radial through-holes 11.

[0051] Regarding the temperature measurement method, further, the diameter of the radial penetration hole 11 is larger than the diameter of the thermocouple wire 8, and the remaining gap of the radial penetration hole 11 after the thermocouple wire 8 is installed is filled with resin. Specifically, the diameter of the radial penetration hole 11 is 1 mm, and the diameter of the thermocouple wire 8 is 0.5 mm. The temperature measuring device of the present application fills the radial penetration hole 11 with resin to prevent the thermocouple wire 8 from shaking in the radial penetration hole 11, thereby ensuring the measurement stability; and the resin is the same as the component resin of the heat-proof layer 3 (a component material of the heat-proof layer 3), that is, the same as the component resin of the protective cover 2, so that the materials of the measuring core 1 and the protective cover 2 are highly compatible and the connection reliability is good.

[0052] Regarding the temperature measurement method, in one embodiment, the temperature measurement device further includes a pressing cover plate 5. The pressing cover plate 5 is fixed to the inner surface of the load-bearing housing 4 by a set screw 7, and the pressing cover plate 5 is in close contact with the inner end face of the measurement core 1. The pressing cover plate 5 presses the measurement assembly in the mounting holes of the load-bearing housing 4 and the heat-insulating layer 3. A lead hole 51 is provided in the center of the pressing cover plate 5; wire grooves 12 communicating with the inner end face are provided at both ends of the radial through hole 11 of the measurement core 1. Both ends of the measurement core 1 are led out to the inner end face through the wire grooves 12 and pass through the lead hole 51, and are connected to the data acquisition device after passing through. The radial through hole 11 is arranged radially, and the wire grooves 12 are arranged axially. The pressing cover plate 5 of the present application further strengthens the connection stability.

[0053] In the description of the present application, it should be noted that the orientation or positional relationship indicated by terms such as "upper" and "lower" is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present application. Unless otherwise clearly specified and limited, the terms "mounted", "connected" and "connected" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0054] It should be noted that in the present application, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprising", "including" or any other variation thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not expressly listed, or also includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "comprising a..." does not exclude the existence of additional identical elements in the process, method, article or device including the element.

[0055] The above are only specific embodiments of the present application, enabling those skilled in the art to understand or implement the present application. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to these embodiments shown herein, but rather to the broadest scope consistent with the principles and novel features claimed herein.

Claims

1. A temperature measurement device for the thermal protection layer of an aircraft, characterized in that: The temperature measurement device includes a measurement component, the measurement component penetrates through the load-bearing shell (4) and the thermal protection layer (3), and the outer end surface of the measurement component is flush with the outer surface of the thermal protection layer (3); several thermocouple wires (8) for measuring temperature are arranged inside the measurement component, the thermocouple wires (8) are parallel to the outer end surface of the measurement component, and the distances of each thermocouple wire (8) from the outer end surface of the measurement component are different; the material of the measurement component is the same as that of the thermal protection layer (3); The measurement component includes a measurement core (1) and a protective sleeve (2), the protective sleeve (2) penetrates through the load-bearing shell (4) and the thermal protection layer (3), and is in interference fit with the thermal protection layer (3), and a certain margin gap is reserved between the circumferential surface of the protective sleeve (2) and the load-bearing shell (4); the measurement core (1) is in interference fit through the center of the protective sleeve (2); the thermocouple wires (8) are arranged inside the measurement core (1); The measurement core (1) is provided with several radially penetrating holes (11) for accommodating the thermocouple wires (8), and the temperature measurement device further includes a pressing cover plate (5), the pressing cover plate (5) is fixed to the inner surface of the load-bearing shell (4) by a set screw (7), and the pressing cover plate (5) is closely attached to the inner end surface of the measurement core (1); a lead hole (51) is opened in the center of the pressing cover plate (5); the measurement core (1) is provided with wire collecting grooves (12) communicating to its inner end surface at both ends of the radially penetrating hole (11), and both ends of the measurement core (1) are led out to the inner end surface through the wire collecting grooves (12) and pass through the lead hole (51).

2. The temperature measuring device for the heat insulation layer of an aircraft according to claim 1, characterized in that: The outermost thermocouple wire (8) among several thermocouple wires (8) is at a set distance from the outer end surface of the measurement core (1), and the remaining thermocouple wires (8) are arranged at equal intervals from the outside to the inside.

3. The temperature measuring device for the heat protection layer of an aircraft according to claim 1, characterized in that: The sensitive part of the thermocouple wire (8) is located at the center of the length direction of the radially penetrating hole (11).

4. The temperature measuring device for the heat insulation layer of an aircraft according to claim 3, wherein: The diameter of the radially penetrating hole (11) is larger than the diameter of the thermocouple wire (8), and the remaining gaps after installing the thermocouple wire (8) in the radially penetrating hole (11) are filled with resin.

5. A method for designing the thickness of the heat shield of an aircraft, based on the temperature measuring device described in claim 1, characterized in that, Including the following steps: Installing holes are opened in the load-bearing shell (4) and the thermal protection layer (3); at the same time, several thermocouple wires (8) are installed inside the measurement component, and the thermocouple wires (8) are parallel to the outer end surface of the measurement component; the thermal protection layer (3) is of a designed thickness; The aircraft conducts a flight test, and the thermocouple wires (8) measure the temperature data during flight; The surface heat flux is calculated by using an inversion algorithm according to the temperature data, the calculated surface heat flux is compared and analyzed with the predicted value of the surface heat flux, and the designed thickness of the thermal protection layer is thickened or thinned according to the analysis result.

6. The thickness design method of the heat protection layer of the aircraft according to claim 5, characterized in that: The sensitive part of the thermocouple wire (8) is located at the center of the length direction of the radially penetrating hole (11); the diameter of the radially penetrating hole (11) is larger than the diameter of the thermocouple wire (8), and the remaining gaps after installing the thermocouple wire (8) in the radially penetrating hole (11) are filled with resin.

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