The Phase Dynamics of Turbulent Taylor Vortex Flow

We study the phase dynamics of turbulent Taylor vortex flow by applying a forced modulation to the upper boundary of a large-aspect-ratio system of concentric cylinders. The experiment shows that the axial phase variable of the turbulent Taylor vortex flow is a deterministic variable and its dynamics can be described by a simple diffusion model. The resultant diffusion coefficient of the turbulent Taylor vortex flow is about an order of magnitude larger than that of laminar/regular Taylor vortex flow. We argue that the approach of phase dynamics can also be applied to turbulent flows as long as there is, on sufficiently long-time scales, a coherent structure discernable in the system.