Optical fiber FBG linear sensing systems for the on-line monitoring of airborne high temperature air duct leakage

Abstract

Electrical Sensing System, such as those involving eutectic salt, are mostly used in connection to leakage from existing airborne high-temperature air-conducting pipelines. Such complex structured systems are susceptible to external interferences and, thus, cannot meet the increasingly strict monitoring needs of a complex air-conducting pipeline system of an aircraft. In view of this, this paper studies an alternative sensor system based on a dense array fiber grating. To obtain a compact and light-weight airborne signal processing system, a field programmable gate array is used as the main control core that controls the output of the light source. The functions of pulse modulation, analog-to-digital conversion, data buffering and transmission are integrated into a single system, while linear sensing monitoring is obtained by detecting the time-division and wavelength-division wavelength drift signals of the fiber Bragg grating array. Our experiments show that the spatial resolution of the linear sensing system approaches 5 cm, the temperature measurement accuracy reaches 2 ℃, the temperature measurement range is between 0-250 ℃, and the response time is within 4 s. Compared with the existing electrical monitoring system, various monitoring indicators have been greatly improved and have broad application prospects.

Research on a linear fiber optical sensor used for leakage detection of aircraft duct

“…During aircraft operation, the bleed air duct is subjected to high temperatures and pressures, making it susceptible to risks such as corrosion, external forces, aging insulation caused by harsh environments, and potential leakage with severe consequences [2] . To enable real-time monitoring and immediate response for the bleed air duct under long distances and bending paths within high-temperature environments, it is essential for measuring equipment to achieve multi-point distributed measurements while also providing real-time positioning capabilities [4] .…”

Vector fiber Bragg gratings accelerometer based on silicone compliant cylinder for low frequency vibration monitoring

“…The acquisition of vibration acceleration signals has significant applications in multiple fields, such as oil and gas seismic exploration, [1][2][3] real-time identification of human activity, [4] structural health monitoring and damage detection, [5] on-line monitoring of airborne air duct leakage, [6] automotive, and aerospace applications. [7] However, with the development of science and technology, scalar information no longer meets the needs of real-time and accurate acceleration measurement.…”