Wavelet Analysis of Rotating Flow
Yoshinori Ueki, Katuhiko Tachibana · Journal of the Visualization Society of Japan · 1997
The turbulent shear flow around a rotating cylinder in a quiescent flow is a simple case of rotating turbulent flow field, where centrifugal force works and an instantaneous fluctuation velocity is affected by Coriolis force. Two different power law mean velocity distributions exist in this flow field. One is Uα1/γ and the other is Uα1/γ2, where γ is a distance from the surface of a cylinder. Velocity fluctuation are invetigated by the wavelet transform using Mexican-hat, French-hat, antisymmetric and Morlet Wavelet. Contours of the wavelet transform in the (a, b) parameter space are found to be similar for the four wavelets if the aand b-axes are properly translated., where a is the scale and b is the temporal location of the center of the wavelet. The Morlet wavelet yields the most detailed multi-scale structure of the velocity fluctuations among the four wavelets.