A blade tip-timing measurement study based on eddy current technology

A blade tip-timing measurement method based on eddy current technology has been proposed using the electromagnetic induction principle. The relationship between output voltage signal and tip clearance variation was achieved by blade calibration,and the blade tip-timing signal was collected by a high-speed data acquisition device. The measurement signal was calculated by post-processing with a reasonable algorithm in order to obtain the blade tip clearance and blade vibration parameters in the operating state. The test results were consistent with theoretical analysis in a test bench,which indicated that the method gives accurate blade tip clearance and blade vibration amplitude data. Furthermore,compared with the traditional capacitance technology and optical fiber technology,our new method is better able to resist environmental interference,has a higher engineering practical value, and performs long-term condition monitoring tasks effectively.