发动机涡轮转子叶片叶尖定时信号干扰与抑制

The non-contact measurement principle of rotor blade tip timing and the working characteristics of optical fiber timing sensor were introduced. The optical fiber sensor with cooling was applied to the vibration test of engine turbine rotor blade to obtain the blade tip timing pulse signal under high temperature and high rotational speed. The results showed that when the rotational speed was greater than 12 513 r/min (working temperature at the blade testing position was 1 326 K), the pulse signal had serious interference, and the system cannot trigger the threshold and record the time of arrival. The causes of interference signal were analyzed, and the solutions of filtering and blue light emission to reduce signal interference were provided. The non-contact vibration test of engine turbine rotor blade was carried out to verify the proposed method. The results showed that the red light radiation can be suppressed only by filtering, and the signal interference above 12 513 r/min was improved, but the interference still existed when the rotational speed exceeded 12 605 r/min (working temperature at blade testing position was 1 375 K); the combination of blue light emission and filtering can effectively solve the interference problem under high temperature and high rotational speed. Below 12 702 r/min (working temperature of blade testing position was 1 388 K), the pulse waveform of blade tip timing signal was good, and the system allowed for effective triggering and timing.