Analysis Of The Blade Vibration Based On The Casing Vibration Signal

Rotor blade is the core components of the gas turbine engine, it is very important to the safe operation of the engine. Therefore, research on fault diagnosis method is of great significance. Tip timing blade condition monitoring method is the widely used method, in the installation of sensors changes the structure of the engine, high-cost, and difficult to apply to the condition monitoring. In this paper, the natural frequency of the blade is monitored, and the sensor installation is simple, and it will not affect the operation state of the engine. At the same time, order tracking as the key techniques of data processing was studied, and the influence factors of the accuracy are analyzed. The correctness and effectiveness of the proposed algorithm are verified by experiments.The main research work of this paper is as follows:(1) The principle and spectral analysis of the method to get the blade natural frequency based on casing vibration are studied. The feasibility and effectiveness of the method are verified by the experimental results of the blade rotor test rig.(2) Study the principle of the computed order tracking. The factors affecting the accuracy of computed order tracking are studied by simulating the signal of different acceleration, sample rate, speed and so on. Experiments were carried out in the ZT-3 rotor test rig, and compared with the commercial software YiHeng, the practicability of the algorithm was verified.(3) The basic principle and data preprocessing method of the recursive least-square order tracking algorithm(RLS) are studied. In the data preprocessing, the pulse signal is converted into rotating speed signal, then the rotating speed signal is converted to the angular displacement signal. The RLS method is performed by the angle displacement signal and the vibration signal. The experimental results of the ZT-3 rotor test rig are compared with the computed order tracking method, and the effectiveness and advantages of the proposed algorithm are discussed.(4) Matlab-GUI based analysis software is developed. Software covers the analysis of blade natural frequency use casing vibration signal, the computed order tracking, the recursive least-square order tracking algorithm and other functions, the software is simple and easy to operate.