Abstract
When the periodic velocity fluctuation is introduced in the mean flow, the separation flow changes in various manners. This report concerns with the “flapping” motion of the separation shear layer by means of the phase averaging of instantaneous velocity profiles over the separation region. In order to know the principal motion of the velocity profile precisely, wavelet transform with Morlet wavelet is used. The shapes of profile are quite different at each phase and with the frequency of the fluctuation. When the suitable frequency was chosen, the phase averaged velocity profile is changing periodically between the profile of “inflection type” and “boundary layer type”.
