Non-reversiblity in periodically driven flows by viscous dephasing
Abstract
We show that in generic situations a reversible periodic driving of a low-Reynolds number flow will not result in a reversible flow field. In the famous experiment of GI Taylor with a blob of dye between concentric cylinders only a single eigenmode of the Stokes operator is involved and reversibility is assured. In generic situations several modes are present and since each eigenmode responds with a phase delay that depends on its eigenvalue and the driving frequency, not all modes will be in phase anymore. Such a viscous dephasing then breaks time reversal symmetry. The general theory is illustrated for 2-d vortex patterns that can be generated in current driven flows in a magnetic field.
- Publication:
-
APS Division of Fluid Dynamics Meeting Abstracts
- Pub Date:
- November 2004
- Bibcode:
- 2004APS..DFD.MM002E