利用光纤光栅压强传感机构和汾丘里管设计了一种基于光纤光栅的流速传感器,并推导了光纤光栅中心波长漂移量与流速的关系式。实验表明,该传感器具有较高的灵敏度,稳定性较好,光纤光栅的中心波长随流速的增加而不断向短波方向漂移,而带宽几乎没有变化,实验和理论符合得较好。该流速传感器的动态感测范围为51.0～148.2 mm/s,在该范围内,至少可感测到0.3 mm/s的流速变化,这是目前所报道的最优值。优化光纤光栅压强传感机构及汾丘里管的参量,可测量其它速度段的流速,并可进一步提高传感灵敏度。

A novel flow velocity sensor based on fiber grating by using the fiber grating pressure sensing setup and Venturi tube is designed. The expression of relationship between the flow velocity and the shift of central wavelength of fiber grating is derived and the experimental results are in good agreement with theoretical analysis. The central wavelength of fiber grating shifts to the shorter wavelength with rise of the flow velocity, while the bandwidth is almost unchanged. The sensor is very sensible to the flow velocity, and very stable. The measuring range is 51.0～148.2 mm/s and in that range the sensor can distinguish the change of the flow velocity as low as 0.3 mm/s which is the lowest to our knowledge. By optimizing the parameters of the sensor, the sensitivity can be improved and it can measure the velocity of different ranges.