Application of a radar system as a method for studying the turbogenerator blade assembly

Abstract

Radar probing is a system for experimental study of various physical objects and environments, widely used both in longrange objects (for example, in remote sensing of the Earth, atmosphere and space objects), and in short-range objects: non-destructive testing, medical diagnostics, etc. The operating principle is based on the Doppler effect. It allows recording the movement of surface areas in the range of speeds from several nanometers per second to transonic, with registration of the frequency spectrum of oscillations. The main advantages of the method are the contactless, non-disturbing nature of measurements, their continuity, allowing for real-time diagnostics, high potential accuracy, as well as the ability to determine the internal structure of objects and environments that are transparent to probing radiation. The measuring complex developed by VtBIS LLC based on the system allows determining the position of the blades relative to each other in a working turbine at a rotation frequency of up to 15,000 rpm, which allows measuring the natural frequencies of turbine blade oscillations and the amplitudes of forced blade oscillations, as well as measuring the amplitude-frequency characteristics of forced oscillations of a blade oscillating in an external alternating magnetic field. The operability and reliability of such measuring equipment is confirmed by experimental data. This makes it possible to use it as a tool for studying the state of a blade assembly in gap measurement systems or for the discrete-phase method in order to improve the efficiency of its operation.