Turbine Vibration Measuring Method And Pressure Measuring Method Based On The FBG Sensor

It's a problem seeking solution for power industry, energy industry, aviation and shipping to real-time measure the high-speed rotating turbine vibration. The conventional measurement technique is difficult to measure the vibration of all blades in one stage at the same time. Therefore foreign scholars have been applying themselves to research a new measurement technique using blade tip-timing. This dissertation researches the blade vibration measurement technique according to the requirement of the basic defence project sponsored by×××××××××.The main work included in the dissertation are shown as follows:(1) A three dimensional mathematical model of blade is established, then the vibration characteristics and the distribution of stress and strain of the model were calculated with ANSYS.(2) The distribution of stress and strain of the rotating blade is measured by FBG sensor. Comparing with the result of ANSYS.(3) Based on the structure of the C- type Bourdon Tube, an optical Brag fiber grating pressure has been presented. The tuning of the FBG reflected wave length is carried out by using the excess pressure in the C- type Bourdon tube for making the surface of the said tube produce stress. The linear relationship of FBG reflected wavelength variation against the pressure has been obtained. In a pressure range of 0～4MPa , the relationship between FBG reflected wave length and pressure is a linear characteristic, with the sensitivity of the pressure reaching 0.0955nm/MPa. Finally the methods about how to improve the static pressure sensing characteristic and heat stability are presented.