Fiber optic liquid level sensor system for aerospace applications

Abstract

Detection of the liquid level in fuel tank becomes a critical element for the safety and efficiency in aerospace operations. Two liquid level sensing techniques are presented in this paper. The first technique is based on optical fiber Long Period Gratings (LPG). In this system, the full length of a specially fabricated fiber is the body of the probe because the length of the sensing fiber that is submerged in the liquid can be detected by the interrogation system. The second system based on Total Internal Reflection (TIR) uses optical fibers to guide light to and from an array of point probes. These probes are specially fabricated, miniature optical components which reflects a substantial amount of light back into the lead fiber when the probe is gas but almost no light when it is in liquid. A detailed theoretical study by computer simulation was carried out on these two techniques in order to determine which technique was more suitable for experimental investigation. The study revealed that although the first technique may provide more potential benefits in terms of weight and easy installation; a number of technical challenges make it not suitable for a short term solution. The second, probe array based technique, on the other hand, is more mature technically. The rest of the research program was therefore focused on the experimental investigation of the probe array detection technique and the test results are presented in this paper.

Fabricating and controlling PCL electrospun microfibers using filament feeding melt electrospinning technique

“…Fiber fabrication is a fascinating technology and is widely used for specialized applications in diverse disciplines including: automobile, air and space industries, and biomedical and tissue engineering [1][2][3][4][5][6][7][8]. Due to its critical role in the production of three dimensional (3D) structures, such fiber fabrication technologies have opened new avenues, specifically for designing novel and smart fibrous structures with various functionalities and engineered properties [9][10][11][12][13][14].…”