Research Of Measuring Method And System Using Tip-timing For High-Speed Rotating Blade Vibration

It's a problem desiderating solution for power industry, energy industry, aviation and shipping to real-time measure the high-speed rotating blade vibration. The conventional contacting measurement technique is difficult to measure the vibration of all blades in one stage at the same time. So foreign scholars have being applying them to research a new non-contact measurement technique using blade tip-timing. This dissertation researches the non-contact blade vibration measurement technique according to the requirement of a national defense pre-research project "The research of non-contact measurement technique of rotating blade vibration" sponsored by Ministry of General Equipment of PLA (HC202-1502-01-02). The main work included in the dissertation are shown as follows:A novel high-speed real-time measurement system of vibration of rotating blade is built for the first time in China, which solve three key technologies: blade tip-timing sensor, collection and pre-processing of high-speed pulse signals and the analysis of measured data. Fiber-optic blade tip-timing sensor pertain to high-speed and real-time measurement is designed and developed, whose output frequency band is larger than 100MHz and measurement distance reaches 0.5mm.The collection and pre-process circuit of high-speed pulse signals based on the fixed frequency pulse filling in time interval method is designed to measure the time interval. The time resolution is 10ns. When the displacement precision is 25μm, the system can measure the vibration of blade whose radius is less than 1.5m and the rotating speed is 50~15000rpm.The process methods of tip-timing measured data are discussed in detail and a fire-new 5+2 fast algorithm is presented to analyze and process the asynchronous and synchronous vibration data, which improve the ability of real-time process signals.A vibration-type expert system is applied to overcome the disadvantage of tip-timing measurement method in vibration-type measurement. The simulation and actual experiments using this expert system are done and satisfactory results are gained.