Surface heat flux measurement system for silicon carbide composite components of aircraft engine nozzles

Abstract

The application relates to a surface heat flow measuring system for a silicon carbide composite material component of an aircraft engine tail nozzle, which comprises a countersunk nail connected to the silicon carbide composite material component, the head surface of the countersunk nail is flush with the surface of the silicon carbide composite material component, and the countersunk nail has a stepped through hole; the small hole of the stepped through hole extends to the head of the countersunk nail, and the large hole of the stepped through hole extends to the top end of the countersunk nail; a coaxial thermocouple is arranged at the head of the small hole of the stepped through hole; a threaded sleeve is sleeved on the lead wire of the coaxial thermocouple, screwed in the large hole of the stepped through hole, and abuts against the head of the coaxial thermocouple, so that the head of the coaxial thermocouple is flush with the surface of the head of the countersunk nail; a high-speed collector is connected to the coaxial thermocouple, collects the voltage signal of the measuring temperature of the coaxial thermocouple, and obtains the measuring temperature of the coaxial thermocouple; and a host computer is connected to the high-speed collector, takes the measuring temperature of the coaxial thermocouple as a boundary condition, and obtains the surface heat flow of the silicon carbide composite material component.

Description

Technical Field

[0001] This application belongs to the field of surface heat flow measurement technology for silicon carbide composite material components of aero-engine tail nozzles, and specifically relates to a surface heat flow measurement system for silicon carbide composite material components of aero-engine tail nozzles. Background Technology

[0002] The tail nozzle of an aircraft engine is subjected to high temperature and high speed exhaust gas scouring, and bears extremely high temperature load. A large amount of high temperature resistant silicon carbide composite material is used in it. When testing the tail nozzle, it is necessary to measure the heat flow on the surface of the silicon carbide composite material component.

[0003] Currently, when conducting tests on aero-engine exhaust nozzles, heat flow measurements are mostly performed using thermocouples mounted on the surface of silicon carbide composite components. This technical approach has the following drawbacks:

[0004] 1) Installing thermocouples on the surface of silicon carbide composite components will disrupt the surface temperature field of silicon carbide composite components, making it difficult to guarantee the accuracy of measurement results;

[0005] 2) When thermocouples are installed on the surface of silicon carbide composite components, they are subject to high temperature, high-speed airflow, and high vibration load, making it difficult to guarantee the reliability of the installation.

[0006] 3) Thermocouple temperature measurement has a slow response speed, which is difficult to meet the requirements of rapid measurement of heat flow on the surface of silicon carbide composite components in aero-engine tail nozzle tests.

[0007] This application is made in view of the aforementioned technical deficiencies.

[0008] It should be noted that the above background information is only used to assist in understanding the inventive concept and technical solution of this invention, and it does not necessarily belong to the prior art of this application. In the absence of clear evidence that the above information was disclosed on the filing date of this application, the above background information should not be used to evaluate the novelty and inventiveness of this application. Summary of the Invention

[0009] The purpose of this application is to provide a surface heat flow measurement system for silicon carbide composite material components of aero-engine tail nozzles, in order to overcome or mitigate at least one of the known technical defects.

[0010] The technical solution of this application is:

[0011] A surface heat flow measurement system for silicon carbide composite material components of an aero-engine exhaust nozzle includes:

[0012] Countersunk screws are countersunk and connected to silicon carbide composite material components. The head surface of the countersunk screw is flush with the surface of the silicon carbide composite material component and has a stepped through hole. The small hole of the stepped through hole extends to the head of the countersunk screw and the large hole of the stepped through hole extends to the top of the countersunk screw.

[0013] A coaxial thermocouple, the head of which is set in the small hole of a stepped through-hole, and its lead wire is led out through the large hole of the stepped through-hole;

[0014] The threaded sleeve is fitted onto the lead wire of the coaxial thermocouple and screwed into the large hole of the stepped through hole, pressing against the head of the coaxial thermocouple so that the head of the coaxial thermocouple is flush with the surface of the countersunk head.

[0015] A high-speed data acquisition unit is connected to a coaxial thermocouple to acquire the voltage signal of the temperature measured by the coaxial thermocouple and obtain the measured temperature of the coaxial thermocouple.

[0016] The host computer is connected to a high-speed data acquisition unit, and the surface heat flow of the silicon carbide composite material component is obtained by using the temperature measured by the coaxial thermocouple as the boundary condition.

[0017] According to at least one embodiment of this application, the above-described surface heat flow measurement system for silicon carbide composite material components of aero-engine exhaust nozzles further includes:

[0018] A heat-insulating and vibration-damping pad is fitted around the outer circumference of the threaded sleeve;

[0019] The self-locking nut is screwed onto the threaded sleeve to press the heat insulation and vibration damping pad onto the silicon carbide composite material component.

[0020] According to at least one embodiment of this application, in the above-mentioned heat flow measurement system for the surface of silicon carbide composite material components of aero-engine tail nozzles, the host computer uses the temperature measured by the coaxial thermocouple as a boundary condition to determine the heat flow on the surface of the silicon carbide composite material component, specifically as follows:

[0021] Construct the heat conduction equation for the homogeneous wall surface of silicon carbide composite components: in,

[0022] T(x,t) is the temperature of the silicon carbide composite component at time t with wall thickness x.

[0023] k is the thermal conductivity coefficient of the silicon carbide composite component;

[0024] ρ is the density of the silicon carbide composite component;

[0025] c represents the specific heat of the silicon carbide composite component;

[0026] Based on the heat conduction equation of the homogeneous wall surface of silicon carbide composite components, and using the measured temperature of the coaxial thermocouple as the boundary condition, T(x,t) is calculated.

[0027] Determine the surface heat flow of silicon carbide composite components Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the surface heat flow measurement system for silicon carbide composite material components of aero-engine tail nozzles provided in this application embodiment;

[0029] in:

[0030] 1-Counterhead screw; 2-Silicon carbide composite material component; 3-Coaxial thermocouple; 4-Threaded sleeve; 5-High-speed data acquisition unit; 6-Host computer; 7-Heat insulation and vibration damping pad; 8-Self-locking nut.

[0031] To better illustrate this embodiment, some parts in the accompanying drawings may be omitted, enlarged, or reduced, and do not represent the actual product dimensions. Furthermore, the drawings are for illustrative purposes only and should not be construed as limiting this application. Detailed Implementation

[0032] To make the technical solution and advantages of this application clearer, the technical solution of this application will be described in a clearer and more complete manner below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only some embodiments of this application, and are only used to explain this application, not to limit this application. It should be noted that, for ease of description, only the parts related to this application are shown in the accompanying drawings. Other related parts can be referred to the general design. In the absence of conflict, the embodiments and technical features in the embodiments of this application can be combined with each other to obtain new embodiments.

[0033] Furthermore, unless otherwise defined, the technical or scientific terms used in this application description shall have the ordinary meaning understood by one of ordinary skill in the art to which this application pertains. The terms "upper," "lower," "left," "right," "center," "vertical," "horizontal," "inner," and "outer," etc., used in this application description to indicate relative direction or positional relationship are used only to indicate relative orientation or positional relationship, and do not imply that the device or component must have a specific orientation, or be constructed and operated in a specific orientation. When the absolute position of the described object changes, its relative positional relationship may also change accordingly, and therefore should not be construed as a limitation on this application. The terms "first," "second," "third," and similar terms used in this application description are used only for descriptive purposes to distinguish different components, and should not be construed as indicating or implying relative importance. The terms "a," "one," or "the," etc., used in this application description should not be construed as an absolute limitation on quantity, but should be construed as indicating the existence of at least one. The terms "including," "comprising," etc., used in this application description mean that the element or object preceding the word covers the element or object listed after the word and its equivalents, without excluding other elements or objects.

[0034] Furthermore, it should be noted that, unless otherwise explicitly specified and limited, terms such as “installation,” “connection,” and “linkage” used in the description of this application should be interpreted broadly. For example, a connection can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; or it can be a connection within two components. Those skilled in the art can understand its specific meaning in this application according to the specific circumstances.

[0035] The following is in conjunction with the appendix Figure 1 This application will be described in further detail.

[0036] A surface heat flow measurement system for silicon carbide composite material components of an aero-engine exhaust nozzle includes:

[0037] Countersunk nail 1 is countersunk and connected to silicon carbide composite component 2. Its head surface is flush with the surface of silicon carbide composite component 2 and has a stepped through hole. The small hole of the stepped through hole extends to the head of countersunk nail 1 and the large hole of the stepped through hole extends to the top of countersunk nail 1.

[0038] The coaxial thermocouple 3 can be a high-temperature heat flow-temperature composite sensor. Its head is set in the small hole of the stepped through-hole, and its lead wire is led out through the large hole of the stepped through-hole.

[0039] The screw sleeve 4 is fitted onto the lead wire of the coaxial thermocouple 3 and screwed into the large hole of the stepped through hole, pressing against the head of the coaxial thermocouple 3 so that the head of the coaxial thermocouple 3 is flush with the surface of the countersunk screw 1.

[0040] High-speed data acquisition unit 5 is connected to coaxial thermocouple 3 to acquire the voltage signal of temperature measured by coaxial thermocouple 3 and obtain the measured temperature of coaxial thermocouple 3.

[0041] The host computer 6 is connected to the high-speed data acquisition unit 5. The temperature measured by the coaxial thermocouple 3 is used as the boundary condition to obtain the surface heat flow of the silicon carbide composite material component.

[0042] Regarding the surface heat flow measurement system for silicon carbide composite material components of aero-engine tail nozzles disclosed in the above embodiments, those skilled in the art will understand that its design uses countersunk nails 1 to create stepped through holes, and with the help of threaded sleeves 4, the head of the coaxial thermocouple 3 is installed on the surface of the silicon carbide composite material component 2. This embedded installation protects the coaxial thermocouple 3 from the scouring of hot, high-speed airflow, ensuring reliable installation even under high vibration loads. Furthermore, the countersunk nail 1 and the head of the coaxial thermocouple 3 are flush with the surface of the silicon carbide composite material component 2, preventing disruption of the temperature field on the surface and guaranteeing the accuracy of the measurement results. In addition, the system is designed to connect the host computer 6 and the high-speed data acquisition unit 5 to the coaxial thermocouple 3, acquiring the voltage signal from the measured temperature of the coaxial thermocouple 3 to obtain the measured temperature of the coaxial thermocouple 3. Then, using the measured temperature of the coaxial thermocouple 3 as a boundary condition, the surface heat flow of the silicon carbide composite material component is calculated. This high-speed system can meet the rapid measurement requirements of surface heat flow for silicon carbide composite material components in aero-engine tail nozzle testing.

[0043] The silicon carbide composite component 2 has poor machinability. In the heat flow measurement system for the surface of silicon carbide composite component of the aero-engine tail nozzle disclosed in the above embodiment, the head of the coaxial thermocouple 3 is installed on the surface of the silicon carbide composite component 2 by countersunk nail 1 and threaded sleeve 4. Only the mounting hole of countersunk nail 1 needs to be opened on the silicon carbide composite component 2, without the need to open additional complex holes, thus avoiding serious damage to the silicon carbide composite component 2.

[0044] In some optional embodiments, the above-described surface heat flow measurement system for silicon carbide composite material components of aero-engine exhaust nozzles further includes:

[0045] The heat insulation and vibration damping pad 7 is fitted around the outer periphery of the threaded sleeve 4 and can be made of quartz material.

[0046] The self-locking nut 8 is screwed onto the threaded sleeve 4, pressing the heat insulation and vibration damping pad 7 onto the silicon carbide composite material component 2 for effective heat insulation and vibration damping.

[0047] In some optional embodiments, in the above-mentioned heat flow measurement system for the surface of silicon carbide composite material components of aero-engine tail nozzles, the host computer 6 uses the measured temperature of the coaxial thermocouple 3 as a boundary condition to determine the heat flow on the surface of the silicon carbide composite material component. Specifically, the heat flow is solved by inversion using one-dimensional heat conduction theory, as detailed below:

[0048] Construct the heat conduction equation for the homogeneous wall surface of silicon carbide composite components: in,

[0049] T(x,t) is the temperature of the silicon carbide composite component at time t with wall thickness x.

[0050] k is the thermal conductivity coefficient of the silicon carbide composite component;

[0051] ρ is the density of the silicon carbide composite component;

[0052] c represents the specific heat of the silicon carbide composite component;

[0053] Based on the heat conduction equation of the homogeneous wall of the silicon carbide composite component, and with the measured temperature of coaxial thermocouple 3 as the boundary condition, T(x,t) is calculated.

[0054] Determine the surface heat flow of silicon carbide composite components

[0055] In some optional embodiments, in the above-described surface heat flow measurement system for silicon carbide composite material components of aero-engine tail nozzles, the silicon carbide composite material component 2 may be a tail nozzle convergent plate, expander plate, etc.

[0056] The various embodiments in the specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0057] The technical solution of this application has been described in conjunction with the preferred embodiments shown in the accompanying drawings. Those skilled in the art should understand that the scope of protection of this application is obviously not limited to these specific embodiments. Without departing from the principles of this application, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the scope of protection of this application.

Claims

1. A surface heat flow measurement system for silicon carbide composite material components of an aero-engine tail nozzle, characterized in that, include: Countersunk nail (1), countersunk is connected to silicon carbide composite component (2), its head surface is flush with the surface of silicon carbide composite component (2), and it has a stepped through hole; the small hole of the stepped through hole extends to the head of countersunk nail (1), and the large hole of the stepped through hole extends to the top of countersunk nail (1). The coaxial thermocouple (3) has its head set in the small hole of the stepped through hole, and its lead wire is led out through the large hole of the stepped through hole; The screw sleeve (4) is fitted onto the lead wire of the coaxial thermocouple (3) and screwed into the large hole of the stepped through hole, pressing against the head of the coaxial thermocouple (3) so that the head of the coaxial thermocouple (3) is flush with the surface of the countersunk nail (1). The high-speed data acquisition unit (5) is connected to the coaxial thermocouple (3) to acquire the voltage signal of the coaxial thermocouple (3) measuring the temperature and to obtain the measured temperature of the coaxial thermocouple (3). The host computer (6) is connected to the high-speed data acquisition unit (5), and the surface heat flow of the silicon carbide composite material component is obtained by using the measured temperature of the coaxial thermocouple (3) as the boundary condition.

2. The surface heat flow measurement system for silicon carbide composite material components of aero-engine tail nozzles according to claim 1, characterized in that, Also includes: A heat-insulating and vibration-damping pad (7) is fitted around the outer periphery of the threaded sleeve (4); The self-locking nut (8) is screwed onto the threaded sleeve (4) to press the heat insulation and vibration damping pad (7) onto the silicon carbide composite material component (2).

3. The surface heat flow measurement system for silicon carbide composite material components of aero-engine tail nozzles according to claim 1, characterized in that, The host computer (6) uses the measured temperature of the coaxial thermocouple (3) as the boundary condition to determine the surface heat flow of the silicon carbide composite component, specifically: Construct the heat conduction equation for the homogeneous wall surface of silicon carbide composite components: in, T(x,t) is the temperature of the silicon carbide composite component at time t with wall thickness x. k is the thermal conductivity coefficient of the silicon carbide composite component; ρ is the density of the silicon carbide composite component; c represents the specific heat of the silicon carbide composite component; Based on the heat conduction equation of the homogeneous wall of the silicon carbide composite component, and using the measured temperature of the coaxial thermocouple (3) as the boundary condition, T(x,t) is calculated. Determine the surface heat flow of silicon carbide composite components

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