Tilted Fiber Bragg Grating Hot Wire Vector Wind Sensor

Wind speed measurement is of paramount importance in industries such as power plants,coal mines,and chemicals.Known traditional wind meters are mostly studied in the form of mechanics,acoustics and thermals,and are subject to many environmental restrictions.The hot-wire fiber anemometer is becoming a widely studied and valuable sensor,but its defects are mainly manifested by the geometrically modified fiber structure which will weaken the structural strength of the sensor;the coupling efficiency and thermal conductivity are limited by common materials;The structure leads to a complicated structure and a large volume of the sensor.Therefore,based on the above research status,a tilted fiber Bragg grating hot wire vector wind sensor is designed.Firstly,a novel fiber-optic hot wire anemometer based on single-walled carbon nanotubes(SWCNTs)coating and inclined fiber Bragg grating(TFBG)is proposed.The results show that the developed anemometer TFBG can be used both as an optical coupling unit and as a sensing unit,which makes the sensor smaller in size and simplified in structure.Single-walled carbon nanotubes have significant light absorption efficiencies as high as 93%.And at a relatively low pump power of 97.76 mW,the maximum temperature of the local area of the fiber is heated to 146.1 °C.The sensitivity is-0.3667 nm/(m/s)when using the selected TFBG,1.6um film,measuring wind speed of 1.0 m/s.Secondly,the carbon nanotube coated TFBG asymmetric model was created and meshed by GAMBIT.The vector sensor model was simulated by FLUENT software.The wind speed field,temperature field and vortex street were simulated and analyzed.The carbon nanotube-coated TFBG sensor can recognize different wind directions,and the simulation shows that the vortex street has no effect on the sensor.Next,we used a 1:1 concentration of carbon nanotubes for coating and used a molybdenum to perform asymmetric stripping on axisymmetric carbon nanotubes under an electron microscope.After optimizing the sensor,it was found that the wavelength drift of the 25-time carbon nanotube coating was better.And on the built optical path platform,the wind direction data is collected by the sensor under different pump power,different coating thickness and different temperature environment.After the treatment,it is found that if the pump power is large and the coating thickness is high,the sensor Sensitivity is better and direction recognition is stronger.The paper preparation sensor has low power consumption,high sensitivity,small volume,high recognition of wind and wind direction,and can work under special circumstances to achieve the expected measurement results.