title: Decomposition of the modulated waves in a rotating couette system.
abstract: The time-dependent velocity field in a rotating Couette system has been decomposed. Successive instantaneous velocity profiles were obtained by an ultrasonic Doppler velocity profile method, and the spatiotemporal velocity field had been analyzed by two-dimensional Fourier transform. The Fourier spectrum is depicted by intrinsic peaks, and the velocity field cpan be reconstructed with these peak components only, indicating a successful decomposition of the velocity field. This method shows that the so-called broadband component, which is purely spatiotemporal and attributed to chaos, corresponds to a global motion of the wave propagating from roll to roll.
authors.forename: Y
authors.initials: Y
authors.lastname: Takeda
authors.forename: W E
authors.initials: WE
authors.lastname: Fischer
authors.forename: J
authors.initials: J
authors.lastname: Sakakibara