A test method for solid rocket engine test by using optical fiber system
By using a fiber optic system to monitor the internal state of a solid rocket engine in real time, the problem of data acquisition during engine testing was solved, enabling high-precision performance monitoring and design optimization, and improving the level of test technology.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- HUBEI SANJIANG AEROSPACE HONGFENG CONTROL
- Filing Date
- 2022-09-26
- Publication Date
- 2026-05-29
AI Technical Summary
During solid rocket engine testing, it is difficult to obtain key operating status information such as temperature, pressure, and stress inside the engine, which increases the difficulty of engine development.
The system employs a fiber optic system, including a temperature fiber optic sensor, a strain fiber optic sensor, a pressure fiber optic sensor, and a fiber optic demodulation module. Data is acquired and demodulated through the fiber optic demodulation module, and combined with the control unit, it enables real-time monitoring of the engine's internal status.
It improves the testing accuracy and safety of engine test runs, enables reliable understanding of engine performance, optimizes engine design, and enhances the technical level of test runs.
Smart Images
Figure CN115753124B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of solid rocket engine testing technology, and in particular to a testing method for solid rocket engine testing using an optical fiber system. Background Technology
[0002] During solid rocket engine testing, key operational status information such as temperature, pressure, and stress inside the engine is difficult to obtain due to high temperature, high pressure, and sealing conditions. This adds difficulty to engine development and is currently a weakness in solid rocket engine testing. Therefore, optimizing testing methods to obtain information about the engine's internal operating status and understanding its performance is crucial for optimizing engine design and improving engine testing technology. Summary of the Invention
[0003] To address the aforementioned technical problems, this invention proposes a testing method for solid rocket engine testing using an optical fiber system. This method solves the problem of the inability to test internal engine data during solid rocket engine testing, offering high testing accuracy and reliability. It plays a crucial role in understanding engine performance and optimizing engine design, effectively improving the level of engine testing technology.
[0004] A testing method for solid rocket motor testing using an optical fiber system, comprising a temperature optical fiber sensor, a strain optical fiber sensor, a pressure optical fiber sensor, an optical fiber demodulation module, and a control unit, is disclosed below:
[0005] Step 1: Install the temperature fiber optic sensor, strain fiber optic sensor, and pressure fiber optic sensor at the target location on the engine.
[0006] Step 2: Embed the fiber demodulation module into the concrete layer of the outer wall of the test bench. Heat insulation glue is poured around the fiber demodulation module and a heat insulation sheet is covered on the outside of the heat insulation glue.
[0007] Step 3: Connect the temperature fiber optic sensor, strain fiber optic sensor, and pressure fiber optic sensor to the fiber optic demodulation module via connecting wires. The connecting wires are also embedded in the concrete layer of the outer wall of the test bench. Thermal insulation glue is poured around the connecting wires and a thermal insulation sheet is covered on the outside of the thermal insulation glue.
[0008] Step 4: Lead the control line of the fiber optic demodulation module out through the engine nozzle to connect with the control unit, and set the fiber optic demodulation module to sleep mode.
[0009] Step 5: Before the engine test run, set the fiber optic demodulation module to automatic acquisition mode via the control unit;
[0010] Step 6: After the test run is completed, remove the fiber optic demodulation module and extract the test data.
[0011] As a preferred embodiment of the above technical solution, the temperature fiber optic sensor contains a polyimide-coated high-temperature resistant fiber optic grating for measuring temperature changes. It adopts a small-volume packaging method, in which the fiber optic grating is first encased in a capillary steel tube and then encased in a heat-resistant rubber sleeve. The entire length of the sensor is in the form of a cable with a uniform cross-section and a cross-sectional diameter of no more than 1 mm. Multiple temperature fiber optic sensors can be used individually or in series.
[0012] As a preferred embodiment of the above technical solution, the strain fiber sensor contains a polyimide-coated high-temperature resistant fiber grating for measuring strain changes. It adopts a small-volume packaging method, in which the sensing fiber is first wrapped with a heat-resistant rubber sleeve and then disconnected at the fiber grating position to expose the fiber grating. The exposed fiber grating is then encapsulated with potting compound. The entire length of the sensor is in the form of a cable with a uniform cross-section and a cross-sectional diameter of no more than 1 mm. Multiple strain fiber sensors can be used individually or in series.
[0013] As a preferred embodiment of the above technical solution, the pressure fiber optic sensor contains a polyimide-coated high-temperature resistant fiber optic grating for measuring pressure changes. The diameter of the pressure sensor in the pressure fiber optic sensor is no greater than 30 mm and the thickness is no greater than 3 mm. The lead wire of the pressure sensor is encapsulated in a heat-resistant rubber sleeve, and the cross-sectional diameter of the lead wire is no greater than 1 mm. Multiple pressure fiber optic sensors can be used individually or in series.
[0014] As a preferred embodiment of the above technical solution, the fiber demodulation module includes a chassis and a fiber Bragg grating demodulation module, an industrial control computer module, and a power supply module installed inside the chassis. The fiber Bragg grating demodulation module is used to demodulate the center wavelength of the fiber Bragg grating. The industrial control computer module is used to configure the demodulation parameters of the fiber Bragg grating demodulation module and save test data. The power supply module is used to supply power to both the fiber Bragg grating demodulation module and the industrial control computer module simultaneously. The upper part of the fiber Bragg grating demodulation module and the industrial control computer module is covered with a heat-conducting layer. The inner surface of the chassis is covered with a heat insulation layer. The bottom and sides of the chassis are covered with a vibration isolation layer. The heat insulation layer is made of aerogel heat-insulating ceramic fiber material, and the vibration isolation layer is made of vibration-isolieving rubber material.
[0015] As a preferred embodiment of the above technical solution, in step 1, the specific deployment method of the fiber optic sensors is as follows: Before loading the engine with propellant, the temperature fiber optic sensor, strain fiber optic sensor, and pressure fiber optic sensor are tightly attached to the target test position using a quick-drying adhesive. At least one temperature fiber optic sensor is deployed at the engine combustion surface to record the engine ignition time, and at least one strain fiber optic sensor or pressure fiber optic sensor is deployed at the interface of the insulation layer on the inner surface of the engine housing to record the engine test end time. All fiber optic sensor leads are led to the interface of the insulation layer on the inner surface of the engine housing and are tightly attached to the interface and led upwards to the top of the test stand. The fiber optic sensor leads are continuously glued and fixed using a quick-drying adhesive.
[0016] As a preferred embodiment of the above technical solution, in step 2, the method for embedding the fiber optic demodulation module into the test bench is as follows: In the concrete layer of the engine outer wall at the top of the test bench, a cutting machine and a crusher are used to excavate a recessed groove that matches the size of the fiber optic demodulation module. The distance between the four sides of the groove and the interface of the insulation layer on the inner surface of the engine housing is not less than 200mm, and the depth of the groove exceeds the height of the fiber optic demodulation module by more than 20mm. The fiber optic demodulation module is then placed into the groove, and heat insulation glue is poured around the fiber optic demodulation module. The top is covered with a heat insulation sheet and filled until it is flush with the top surface of the groove.
[0017] As a preferred embodiment of the above technical solution, in step 3, the method for embedding the fiber optic sensor connection line into the test bench is as follows: a groove is cut in the concrete layer of the engine outer wall at the top of the test bench using a cutting machine, with a cross-sectional size of not less than 20mm*20mm, connecting the fiber optic demodulation module to the heat insulation layer of the engine housing inner wall. The fiber optic sensor connection line enters the groove from the heat insulation layer of the engine housing inner wall, and the fiber optic demodulation module is passed through the groove to complete the connection. Heat insulation glue is poured around the connection line in the groove, and a heat insulation sheet is covered to fill it until it is flush with the top surface of the groove.
[0018] As a preferred embodiment of the above technical solution, the setup method for the fiber optic demodulation module before engine testing in steps 4 and 5 is as follows: After completing the connection between the fiber optic demodulation module and the fiber optic sensor, power on the fiber optic demodulation module, extend its control line from the engine nozzle, and connect it to the control unit. The control unit connects to the fiber optic demodulation module via an RJ45 communication interface, supplies power to the fiber optic demodulation module, logs into the control interface of the fiber optic demodulation module through the control unit, and sets it to enter sleep mode to extend the test preparation time. After the test preparation is completed, within 2 hours before the formal ignition, wake up the fiber optic demodulation module through the control unit, set it to normal working mode, and start continuous data acquisition and storage. Then, disconnect the control line, and the fiber optic demodulation module automatically switches to autonomous power supply mode, enabling the fiber optic demodulation module to work autonomously in a closed loop, continuously acquiring and storing fiber optic sensor data. When the engine is ignited for testing, changes in the internal state are sensed by the fiber optic sensor and continuously acquired and recorded by the fiber optic demodulation module.
[0019] As a preferred embodiment of the above technical solution, in step 6, the engine test data extraction method is as follows: After removing the fiber optic demodulation module, the data file is read through an external USB interface or by removing the internal hard drive, and the data is organized into Data = [T, Sensor1, Sensor2, ..., Sensor...]. n ], where Data represents the dataset, T = [t0, t1, t2, ..., t n [Represents the recording time, Sensor] i =[s0,s1,s2,……,s n [] represents the test data of the i-th sensor. Find the temperature sensor data Sensort0 installed at the combustion surface of the engine, and take the time t corresponding to the peak point of the data. m As the engine test ignition time, locate the strain fiber optic sensor data (Sensors0) or pressure fiber optic sensor data (Sensors0) installed at the interface of the insulation layer on the inner surface of the engine housing, and record their data at t. m The turning point from fluctuation to stability after time t corresponds to time t. n As the end time of engine testing, extract t m To t n All sensor data within the time interval are used as engine test data.
[0020] The beneficial effects of this invention are as follows:
[0021] This testing method solves the problem of the inability to test internal engine data during solid rocket engine testing. It has high testing accuracy, is safe and reliable, and plays an important role in understanding the engine's working performance and optimizing engine design, effectively improving the level of engine testing technology. Attached Figure Description
[0022] Figure 1 This is a schematic diagram of the fiber optic system installation.
[0023] Figure 2 This is a schematic diagram of the internal structure of the fiber optic demodulation module.
[0024] Figure 3 This is a flowchart of the testing method.
[0025] The attached figures are labeled as follows: 1-Temperature fiber optic sensor, 2-Strain fiber optic sensor, 3-Pressure fiber optic sensor, 4-Fiber optic demodulation module, 41-Chassis, 42-Fiber Bragg grating demodulation module, 43-Industrial control computer module, 44-Power supply module, 45-Heat-conducting layer, 46-Heat insulation layer, 47-Vibration isolation layer, 5-Control unit. Detailed Implementation
[0026] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.
[0027] like Figure 1 , Figure 3 The diagram illustrates a testing method for solid rocket motor testing using an optical fiber system. The optical fiber system includes a temperature optical fiber sensor 1, a strain optical fiber sensor 2, a pressure optical fiber sensor 3, an optical fiber demodulation module 4, and a control unit 5. The specific testing method is as follows:
[0028] Step 1: Install the temperature fiber optic sensor 1, strain fiber optic sensor 2, and pressure fiber optic sensor 3 at the target location on the engine.
[0029] Step 2: Embed the fiber demodulation module 4 into the concrete layer of the outer wall of the test bench. Heat insulation glue is poured around the fiber demodulation module 4 and a heat insulation sheet is covered on the outside of the heat insulation glue.
[0030] Step 3: Connect the temperature fiber optic sensor 1, strain fiber optic sensor 2, and pressure fiber optic sensor 3 to the fiber optic demodulation module 4 via connecting wires. The connecting wires are also embedded in the concrete layer of the outer wall of the test bench. Thermal insulation glue is poured around the connecting wires and a thermal insulation sheet is covered on the outside of the thermal insulation glue.
[0031] Step 4: Lead the control line of the fiber optic demodulation module 4 out through the engine nozzle to connect with the control unit 5, and set the fiber optic demodulation module 4 to sleep mode.
[0032] Step 5: Before the engine test run, set the fiber optic demodulation module 4 to automatic acquisition mode via control unit 5;
[0033] Step 6: After the test run is completed, remove the fiber optic demodulation module 4 and extract the test data.
[0034] In this embodiment, the temperature fiber optic sensor 1 contains a polyimide-coated high-temperature resistant fiber optic grating for measuring temperature changes. It adopts a small-volume packaging method, in which the fiber optic grating is first wrapped with a capillary steel tube and then encapsulated in a heat-resistant rubber sleeve. The entire length of the sensor is in the form of a cable with a uniform cross-section and a cross-sectional diameter of no more than 1 mm. Multiple temperature fiber optic sensors 1 can be used individually or in series.
[0035] In this embodiment, the strain fiber sensor 2 contains a polyimide-coated high-temperature resistant fiber grating for measuring strain changes. It adopts a small-volume packaging method. The sensing fiber is first wrapped with a heat-resistant rubber sleeve and then disconnected at the fiber grating position to expose the fiber grating. The exposed fiber grating is then encapsulated with potting compound. The entire length of the sensor is in the form of a cable with a uniform cross-section and a cross-sectional diameter of no more than 1 mm. Multiple strain fiber sensors can be used individually or in series.
[0036] In this embodiment, the pressure fiber optic sensor 3 contains a polyimide-coated high-temperature resistant fiber optic grating for measuring pressure changes. The diameter of the pressure sensor in the pressure fiber optic sensor 3 is no greater than 30 mm and the thickness is no greater than 3 mm. The lead wire of the pressure sensor is encapsulated in a heat-resistant rubber sleeve, and the cross-sectional diameter of the lead wire is no greater than 1 mm. Multiple pressure fiber optic sensors 3 can be used individually or in series.
[0037] like Figure 2 As shown, in this embodiment, the fiber demodulation module 4 includes a chassis 41 and a fiber Bragg grating demodulation module 42, an industrial control computer module 43, and a power supply module 44 installed inside the chassis 41. The fiber Bragg grating demodulation module 42 is used to demodulate the center wavelength of the fiber Bragg grating. The industrial control computer module 43 is used to configure the demodulation parameters of the fiber Bragg grating demodulation module 42 and save test data. The power supply module 44 is used to supply power to both the fiber Bragg grating demodulation module 42 and the industrial control computer module 43. The upper part of the fiber Bragg grating demodulation module 42 and the industrial control computer module 43 is covered with a heat-conducting layer 45. The inner surface of the chassis 41 is covered with a heat insulation layer 46. The bottom and sides of the chassis 41 are covered with a vibration isolation layer 47. The heat insulation layer 46 is made of aerogel heat-insulating ceramic fiber material, and the vibration isolation layer 47 is made of vibration-isolating rubber material.
[0038] In this embodiment, the specific deployment method of the fiber optic sensors in step 1 is as follows: Before loading the engine with propellant, the temperature fiber optic sensor 1, strain fiber optic sensor 2, and pressure fiber optic sensor 3 are tightly attached to the target test position using a quick-drying adhesive. At least one temperature fiber optic sensor 1 is deployed at the engine combustion surface to record the engine ignition time, and at least one strain fiber optic sensor 2 or pressure fiber optic sensor 3 is deployed at the interface of the insulation layer on the inner surface of the engine housing to record the engine test end time. All fiber optic sensor leads are led to the interface of the insulation layer on the inner surface of the engine housing and are tightly attached upwards along the interface to the top of the test stand. The fiber optic sensor leads are continuously glued and fixed using a quick-drying adhesive.
[0039] In this embodiment, the method for embedding the fiber optic demodulation module 4 into the test bench in step 2 is as follows: In the concrete layer of the outer wall of the engine at the top of the test bench, a cutting machine and a crusher are used to excavate a recessed groove that matches the size of the fiber optic demodulation module 4. The distance between the four sides of the groove and the interface of the insulation layer on the inner surface of the engine housing is not less than 200mm, and the depth of the groove exceeds the height of the fiber optic demodulation module by more than 20mm. The fiber optic demodulation module 4 is then placed into the groove, and heat insulation glue is poured around the fiber optic demodulation module. The top is covered with a heat insulation sheet and filled until it is flush with the top surface of the groove.
[0040] In this embodiment, the method for embedding the fiber optic sensor connection line into the test bench in step 3 is as follows: a groove is cut in the concrete layer of the engine outer wall at the top of the test bench using a cutting machine, with a cross-sectional size of not less than 20mm*20mm. The fiber optic demodulation module 4 is connected to the heat insulation layer of the engine housing inner wall. The fiber optic sensor connection line enters the groove from the heat insulation layer of the engine housing inner wall and passes through the groove to complete the connection with the fiber optic demodulation module. Heat insulation glue is poured around the connection line in the groove and covered with a heat insulation sheet until it is flush with the top surface of the groove.
[0041] In this embodiment, the setup method of the fiber optic demodulation module 4 before engine test in steps 4 and 5 is as follows: After completing the connection between the fiber optic demodulation module 4 and the fiber optic sensor, the fiber optic demodulation module 4 is powered on and started. Its control line is led out from the engine nozzle and connected to the control unit 5. The control unit 5 is connected to the fiber optic demodulation module 4 through the RJ45 communication interface. The control unit 5 supplies power to the fiber optic demodulation module 4. The control unit 5 logs into the control interface of the fiber optic demodulation module 4 and sets it to enter sleep mode to extend the test preparation time. After the test preparation is completed, two hours before the formal ignition, the control unit 5 wakes up the fiber optic demodulation module 4, sets it to normal working mode, and starts continuous data acquisition and storage. Then, the control line connection is disconnected, and the fiber optic demodulation module 4 automatically switches to autonomous power supply mode, enabling the fiber optic demodulation module 4 to work autonomously in a closed loop, continuously acquiring and storing fiber optic sensor data. When the engine is ignited for test, changes in the internal state are sensed by the fiber optic sensor and continuously acquired and recorded by the fiber optic demodulation module 4.
[0042] In this embodiment, the engine test data extraction method in step 6 is as follows: After removing the fiber optic demodulation module 4, the data file is read through an external USB interface or by removing the internal hard drive, and the data is organized into Data = [T, Sensor1, Sensor2, ..., Sensor...]. n ], where Data represents the dataset, T = [t0, t1, t2, ..., t n [Represents the recording time, Sensor] i =[s0,s1,s2,……,s n [] represents the test data of the i-th sensor. Find the temperature sensor data Sensort0 installed at the combustion surface of the engine, and take the time t corresponding to the peak point of the data. m As the engine test ignition time, locate the strain fiber optic sensor data (Sensors0) or pressure fiber optic sensor data (Sensors0) installed at the interface of the insulation layer on the inner surface of the engine housing, and record their data at t. m The turning point from fluctuation to stability after time t corresponds to time t. n As the end time of engine testing, extract t m To t n All sensor data within the time interval are used as engine test data.
[0043] The above-mentioned testing method solves the problem of the inability to test internal engine data during solid rocket engine testing. It has high testing accuracy, is safe and reliable, and plays an important role in understanding the engine's working performance and optimizing engine design, effectively improving the level of engine testing technology.
[0044] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.
Claims
1. A test method for conducting solid rocket motor tests using an optical fiber system, characterized in that: The fiber optic system includes a temperature fiber optic sensor, a strain fiber optic sensor, a pressure fiber optic sensor, a fiber optic demodulation module, and a control unit. Specific testing methods are as follows: Step 1: Install the temperature fiber optic sensor, strain fiber optic sensor, and pressure fiber optic sensor at the target location on the engine. Step 2: Embed the fiber demodulation module into the concrete layer of the outer wall of the test bench. Heat insulation glue is poured around the fiber demodulation module and a heat insulation sheet is covered on the outside of the heat insulation glue. Step 3: Connect the temperature fiber optic sensor, strain fiber optic sensor, and pressure fiber optic sensor to the fiber optic demodulation module via connecting wires. The connecting wires are also embedded in the concrete layer of the outer wall of the test bench. Thermal insulation glue is poured around the connecting wires and a thermal insulation sheet is covered on the outside of the thermal insulation glue. Step 4: Lead the control line of the fiber optic demodulation module out through the engine nozzle to connect with the control unit, and set the fiber optic demodulation module to sleep mode. Step 5: Before the engine test run, set the fiber optic demodulation module to automatic acquisition mode via the control unit; Step 6: After the test run is completed, remove the fiber optic demodulation module and extract the test data; The temperature fiber optic sensor contains a polyimide-coated high-temperature resistant fiber optic grating for measuring temperature changes. It adopts a small-volume packaging method, with the fiber optic grating first wrapped in a capillary steel tube and then encapsulated in a heat-resistant rubber sleeve. The entire length of the sensor is in the form of a cable with a uniform cross-section and a cross-sectional diameter of no more than 1 mm. Multiple temperature fiber optic sensors can be used individually or in series. The strain fiber sensor contains a polyimide-coated high-temperature resistant fiber grating for measuring strain changes. It adopts a small-volume packaging method. The sensing fiber is first wrapped with a heat-resistant rubber sleeve and then disconnected at the fiber grating position to expose the fiber grating. The exposed fiber grating is then encapsulated with potting compound. The entire length of the sensor is in the form of a cable with a uniform cross-section and a cross-sectional diameter of no more than 1 mm. Multiple strain fiber sensors can be used individually or in series. The pressure fiber optic sensor contains a polyimide-coated high-temperature resistant fiber optic grating for measuring pressure changes. The diameter of the pressure sensor in the pressure fiber optic sensor is no greater than 30 mm and the thickness is no greater than 3 mm. The lead wire of the pressure sensor is encapsulated in a heat-resistant rubber sleeve, and the cross-sectional diameter of the lead wire is no greater than 1 mm. Multiple pressure fiber optic sensors can be used individually or in series.
2. The test method according to claim 1, characterized in that: The fiber optic demodulation module includes a chassis and a fiber Bragg grating demodulation module, an industrial computer module, and a power supply module installed inside the chassis. The fiber Bragg grating demodulation module is used to demodulate the center wavelength of the fiber Bragg grating. The industrial computer module is used to configure the demodulation parameters of the fiber Bragg grating demodulation module and save test data. The power supply module is used to supply power to both the fiber Bragg grating demodulation module and the industrial computer module simultaneously. The upper part of the fiber Bragg grating demodulation module and the industrial computer module is covered with a heat-conducting layer. The inner surface of the chassis is covered with a heat-insulating layer. The bottom and sides of the chassis are covered with a vibration-damping layer. The heat-insulating layer is made of aerogel heat-insulating ceramic fiber material, and the vibration-damping layer is made of vibration-damping rubber material.
3. The test method according to claim 1, characterized in that: In step 1, the specific deployment method of the fiber optic sensors is as follows: Before loading the engine with propellant, the temperature fiber optic sensor, strain fiber optic sensor, and pressure fiber optic sensor are tightly attached to the target test position using a quick-drying adhesive. At least one temperature fiber optic sensor is deployed at the engine combustion surface to record the engine ignition time, and at least one strain fiber optic sensor or pressure fiber optic sensor is deployed at the interface of the insulation layer on the inner surface of the engine housing to record the engine test end time. All fiber optic sensor leads are led to the interface of the insulation layer on the inner surface of the engine housing and are tightly attached to the interface and led upwards to the top of the test stand. The fiber optic sensor leads are continuously glued and fixed using a quick-drying adhesive.
4. The test method according to claim 1, characterized in that: In step 2, the method for embedding the fiber optic demodulation module into the test bench is as follows: In the concrete layer of the engine outer wall at the top of the test bench, a cutting machine and a crusher are used to excavate a recessed groove that matches the size of the fiber optic demodulation module. The distance between the four sides of the groove and the interface of the insulation layer on the inner surface of the engine housing is not less than 200mm. The depth of the groove exceeds the height of the fiber optic demodulation module by more than 20mm. The fiber optic demodulation module is then placed into the groove. Insulating glue is poured around the fiber optic demodulation module, and an insulating sheet is placed on top to fill it until it is flush with the top surface of the groove.
5. The test method according to claim 1, characterized in that: In step 3, the method for embedding the fiber optic sensor connection line into the test bench is as follows: a groove is cut in the concrete layer of the engine outer wall at the top of the test bench using a cutting machine, with a cross-sectional size of not less than 20mm*20mm. The fiber optic demodulation module is connected to the heat insulation layer of the engine housing inner wall. The fiber optic sensor connection line enters the groove from the heat insulation layer of the engine housing inner wall and passes through the groove to complete the connection with the fiber optic demodulation module. Heat insulation glue is poured around the connection line in the groove and covered with heat insulation sheet until it is flush with the top surface of the groove.
6. The test method according to claim 1, characterized in that: In steps 4 and 5, the setup method for the fiber optic demodulation module before engine testing is as follows: After completing the connection between the fiber optic demodulation module and the fiber optic sensor, power on the fiber optic demodulation module, extend its control line from the engine nozzle, and connect it to the control unit. The control unit connects to the fiber optic demodulation module via an RJ45 communication interface. The control unit supplies power to the fiber optic demodulation module. Log in to the control interface of the fiber optic demodulation module through the control unit and set it to enter sleep mode to extend the test preparation time. After the test preparation is completed, within 2 hours before the formal ignition, wake up the fiber optic demodulation module through the control unit, set it to normal working mode, and start continuous data acquisition and storage. Then, disconnect the control line, and the fiber optic demodulation module automatically switches to autonomous power supply mode, enabling the fiber optic demodulation module to work autonomously in a closed loop, continuously acquiring and storing fiber optic sensor data. When the engine is ignited for testing, changes in the internal state are sensed by the fiber optic sensor and continuously acquired and recorded by the fiber optic demodulation module.
7. The test method according to claim 1, characterized in that: In step 6, the engine test data extraction method is as follows: After removing the fiber optic demodulation module, the data file is read through an external USB interface or by removing the internal hard drive, and the data is organized into Data=[T,Sensor1,Sensor2,……,Sensor n ], where Data represents the dataset, T=[t0, t1,t2, ……, t n [Represents the recording time, Sensor] i =[s0, s1, s2, ..., s n [] represents the test data of the i-th sensor. Find the temperature sensor data Sensort0 installed at the combustion surface of the engine, and take the time t corresponding to the peak point of the data. m As the engine test ignition time, locate the strain fiber optic sensor data (Sensors0) or pressure fiber optic sensor data (Sensors0) installed at the interface of the insulation layer on the inner surface of the engine housing, and record their data at t. m The turning point from fluctuation to stability after time t corresponds to time t. n As the end time of engine testing, extract t m To t n All sensor data within the time interval are used as engine test data.