The techniques of Hilbert and Wavelet transformations were applied to analyze the signals of the MEMS sensors situated on a circular cylinder spanwisely for examining the unsteady, three-dimensional behavior of vortex shedding. The experiments were made at Reynolds numbers of 104. The results of the Hilbert analysis show that o the unsteady, three-dimensional characteristics of vortex shedding are highlighted by the events of vortex dislocation, which might be occurred in a localized spanwise region or over the entire cylinder for a time length up to several vortex shedding periods. The temporal variations of spanwise phase difference of vortex shedding reduced by the Hilbert analysis were noticed in good agreement with those obtained by the Wavelet analysis. On the other hand, it is noted that the temporal variations of Wavelet analysis appear more smoothened than those of the Hilbert analysis. This is attributed to the nature of windowed smoothing of the Wavelet transformation.
|Number of pages||11|
|Journal||Journal of the Chinese Society of Mechanical Engineers, Transactions of the Chinese Institute of Engineers, Series C/Chung-Kuo Chi Hsueh Kung Ch'eng Hsuebo Pao|
|Publication status||Published - 2007 Feb 1|
All Science Journal Classification (ASJC) codes
- Mechanical Engineering