Dispersion and Mixing in Quasi-two-dimensional Rotating Flows

摘要: A new rotating-tank experiment has been set up to investigate several aspects of dispersion in forced quasi-two-dimensional turbulence. By superimposing a harmonically varying perturbation on the mean rotation rate flow continually interacts with no-slip boundaries and forms boundary layers high-amplitude vorticity twice during forcing period. choosing proper amplitude frequency it is possible continuously inject small-scale interior flow, either form filamentary structures (detached layers) or as small vortices (after roll-up detached layers). We present measurements passive scalar spectrum which show good agreement k -1 predicted by Batchelor (J. Fluid Mech. 5:113, 1959). Using particle image velocimetry we are able reconstruct Lagrangian trajectories particles. The relative rates pairs an initial exponential separation followed classical Richardson dispersion, R 2 ∝ t3.0± 0.1. variance absolute displacement grows σ t1.4, similar observations previous experiments Solomon et al. (Phys. Rev. Lett. 71:3975, 1993) Hansen E 58:7261, 1998). Finally, indicating future directions research, results simple chemical reaction quasi-2D turbulence how bulk controlled mixing filamentation processes.