An Optical Fiber Sensing System for Vibration Testing of Engine Internal Flow Channels

Abstract

The invention relates to an optical fiber sensing system for vibration testing of a flow channel in an engine, and belongs to the field of engine testing. This method uses a composite sensitive structure as the core device of the fiber-optic vibration sensor, and connects it with the fiber-optic demodulator through an optical cable to construct a fiber-optic vibration sensing system, which can achieve high g value (1g~500g) and Broadband (5Hz~20kHz) vibration measurement. Through the design of the composite sensitive structure parameters of the optical fiber vibration sensor, the high-frequency large g-value sensitive structure and the low-frequency small g-value sensitive structure are connected with each other in the g-value measurement range, frequency response, and resolution, so as to meet the engine vibration test with a wide frequency response and a large range. need. The sensing system has the characteristics of high temperature resistance, wide frequency response and large range, which can solve the problems of small space and high temperature of the measured part, and can transfer the vibration measurement of the engine from the outer casing to the inside of the engine closer to the vibration source. Accuracy of engine vibration measurements.

Description

technical field [0001] The invention relates to an optical fiber sensing system for vibration testing of a flow channel in an engine, belongs to the technical field of engine testing, and can be used for high-temperature vibration testing in narrow spaces such as a flow channel in an engine. Background technique [0002] The vibration problem of aero-engines has always been a prominent problem in the production and use of engines. According to statistics, more than 60% of aero-engine failures are vibration failures. Therefore, during the development and use of aero-engines, it is necessary to monitor, identify and predict its Changes in operating conditions, through vibration measurement, ensure that the cause and possible location of the failure are identified before the accident occurs, and hidden dangers are eliminated in time to improve the reliability and safety of engine operation. The causes of aero-engine vibration generally include two situations, one is a regular v...

AI Technical Summary

Problems solved by technology

[0005] Common MEMS vibration sensors mainly adopt a support beam-mass sensitive structure. The mass generates displacement under the action of acceleration load, and finally detects the magnitude of the acceleration load. The vibration sensor with support beam-mass structure has high sensitivity. The sensor has high sensitivity and high resolution, but there is a mutual restrictive relationship between the working range, frequency response range and sensitivity, and different structural sizes will produce different performance indicators

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