Research On Diaphragm EFPI Optical Fiber Wind Speed Sensor

With the rapid development of technology and the continuous improvement of industrialization,the requirements for sensors are also increasing.wind speed sensors that are suitable for normal and stable operation in harsh environmental conditions such as wind power generation,wind tunnel experiments,automotive aerodynamic tests,and nautical aviation are particularly important.Because of its simple structure,small size,light weight,anti-electromagnetic interference,and strong corrosion resistance,it has attracted the attention of many researchers.The main work of this paper is to prepare a simple membrane-type extrinsic Fabry-Perot Interferometric?EFPI?optical fiber wind speed sensor.This paper introduces and analyzes the working principle and characteristics of traditional electronic wind speed sensor and existing optical fiber wind speed sensor in detail,and proposes a diaphragm type EFPI optical fiber wind speed sensor based on the principle of differential pressure.The sensor in this thesis uses fused silica?SiO₂?as the diaphragm material,and uses three different sizes of quartz sleeves as the support structure after nesting and bonding.The end surface of the single-mode fiber and the inner surface of the diaphragm constitute Fabry-Perot?F-P?Cavity.The single-mode optical fiber,diaphragm,and sleeve are selected to be bonded by ultraviolet curing adhesive,and the pitot tube is used to guide the static pressure and full pressure in the wind field,so that the diaphragm is deformed under the differential pressure between the static pressure and the full pressure.Then,the phase demodulation method based on cross-correlation calculation is used to demodulate the absolute value of the change in cavity length,and then the wind speed can be calculated according to the Bernoulli equation.During the experiment,the pressure sensitivity and resolution calibration experiments were carried out on the sensor,and the sensitivity of this diaphragm-type EFPI optical fiber wind speed sensor was 826.97 nm/kPa,and the range was 0¹29.896 m/s,which was basically the same as the theoretical calculation It is consistent;afterwards,a wind speed measurement experiment was carried out using the sensor.The experimental results show that the sensor is within the wind speed range of 0²7 m/s,and the measurement error of the sensor does not exceed 0.41 m/s.The diaphragm-type EFPI optical fiber wind speed sensor can have practical application potential in air speed measurement,wind tunnel test,wind power generation,etc.