Optical fiber sensor and method for measuring multiple parameters of air compressor fluid

Abstract

The invention provides a light intensity and optical grating type hybrid fiber flow sensor and a measuring method. Bragg grating type fibers are symmetrically distributed on the surface of an annular elastic strain disc, and static pressure is calculated by the aid of wavelengths in centers of the fibers; light intensity fibers are perpendicularly irradiated to the center of the elastic strain disc, reflected light is received through two groups of receiving fibers, and an offset distance of the elastic strain disc is calculated through light intensity ratios of the two groups of the receiving fibers, so that total pressure is calculated; a temperature measuring grating fiber is adhered to the inner wall of a pitot tube, and the total temperature of the air compressor is calculated according to an offset amount of the center wavelength of the temperature measuring grating fiber; and another temperature measuring grating fiber is horizontally fixed on the inner side of a cylindrical metal casing for measuring the temperature of a work environment, and the total pressure and the static pressure are subjected to temperature compensation. The optical fiber sensor has the characteristics of small size, simple structure, high interference resistance and the like, and the multiple parameters such as the total pressure, the total temperature, the flow and the like of the fluid can be measured through one sensor.

Description

technical field [0001] The invention relates to the technical field of optical fiber sensors for engine gas flow measurement, in particular to a light intensity type and grating type hybrid optical fiber sensor and a measurement method for multi-parameter measurement of compressor fluid. Background technique [0002] Optical fiber sensing technology started in the 1970s and entered our country in the 1990s. At present, many research institutions in China have begun to use this technology for product development and production. For the gas flow sensors that need to be used in special environments such as aviation and aerospace, they are characterized by high dynamic response and good static measurement linearity, as well as anti-electromagnetic interference and good high temperature resistance. [0003] The compressor is one of the core components of an aero-engine, and its working state plays an important role in the normal operation of the entire engine. The compressor wi...

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Problems solved by technology

Therefore, the response speed of this kind of flow sensor is very slow; in the place where the measured gas composition changes greatly, the measurement value will have a large change due to the change of cp value and thermal conductivity, resulting in errors; due to the poor mechanical strength of the optical fiber, for the flow rate Fast compressor outlet, due to the large diameter of the compressor, the fiber may break

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