Comparison of various basic wavelets for the analysis of flow-induced vibration of a cylinder in cross flow

This paper is concerned with the application of wavelet transforms to the analysis of the self-excited how-induced vibration of a single cylinder in a cross-flow. Published experimental data indicates that the vibration signals of the present system, and those of similar ones are, in general, nonstationary. However, these signals have thus far been analysed using classical methods, such as the FFT and correlation methods, wherein the signals are assumed to be stationary and they are analysed either in the time or frequency domain but not in both domains simultaneously. It is shown that wavelet transforms, which are applicable to stationary as well as to nonstationary processes and yield a joint time-frequency analysis and representation of the vibration signals with good localization, can reveal many important aspects of the dynamical process not shown by the classical methods. Various wavelets are used and recommendations regarding the most suitable ones, and the interpretation of the representations, are discussed. (C) 1996 Academic Press Limited