An improved multiple per revolution-based blade tip timing method and its applications on large-scale compressor blades

Abstract

Blade Tip Timing (BTT) is one of the most effective technologies for blade vibration measurement of turbomachinery. The blade vibration measurement indicates the operational status of the blades, which is of great significance for blade health management and fault diagnosis. However, the approaches and applications of BTT technologies are still facing enormous challenges. This study, based on the traditional once per revolution (OPR) methods, the measurement error of blade vibration induced by the speed fluctuation per revolution (SFPR) is investigated. Considering the effect of the SFPR, an improved multiple per revolution-based BTT method (MPR) for calculating the blade vibration is proposed. Furthermore, numerical simulation and experimental work of the MPR method are executed. Compared with the results of different technologies, the feasibility and reliability of the MPR method are verified by theoretical analysis and experimental verification. The MPR technology is also applied to blade vibration measurement of a large-scale Centrifugal Compressor and a large-scale Axial-Centrifugal Compressor. The conclusions of applications are well practical.