Looking for information on compressor (turbine) Campbell diagrams

Thread Content

This post was last edited by 1573 on 2015-3-26 at 10:15. Campbell diagram – in many cases, it is necessary to monitor the dynamic changes in several components of the frequency spectrum related to rotor speed variations, in order to determine the operating characteristics of the rotor across its entire speed range. One of the analytical methods to achieve this goal is the Campbell diagram. The so-called Campbell diagram shows the vibration amplitude at various monitoring points as a function of speed and frequency, thereby illustrating the variation patterns of all components of rotor vibration across the entire speed range. In a Campbell diagram, the horizontal axis represents speed while the vertical axis represents frequency. The forced vibration component, that is, the frequency components related to speed, is depicted on rays originating from the origin; the amplitude is indicated by circles, with the diameter of these circles representing the magnitude of the signal amplitude. The free vibration component, on the other hand, is shown on fixed frequency lines. The Campbell diagram is the most fundamental method in transient signal analysis; it enables one to determine the variation characteristics of all frequency components of rotor vibration across the entire speed range. When a fault occurs in a certain part of the rotor, the Campbell diagram at the time of the fault can be used to identify the speed, frequency, and amplitude of its vibration. This is of great significance for further analyzing the causes of abnormal faults as well as for determining acceptable limits for vibration amplitudes. Request: Information on CAMPBELL graphs, preferably with both text and illustrations, for learning purposes. Thank you! ! !