The energy spectral density of axial velocity components in a rotating Couette-Taylor system was obtained using a Fourier transform of axial velocity distributions. As this configuration has well defined spatial periodicity, strong peaks appear on the spectrum corresponding to Taylor vortex flow and wavy vortex flow modes and their harmonics. A continuous background shows an exponential decay with wave number, which supports the results of the numerical simulations. A variation in the decay rate at reduced Reynolds number shows a maximum at ${\mathit{R}}^{\mathrm{*}}$≊22. At this Reynolds number, an energy exchange between the first and second harmonics was observed.

• Received 4 November 1992

DOI:https://doi.org/10.1103/PhysRevLett.70.3569