The mixing induced by two constant flow rate fans, which vary periodically in direction, is studied as a function of the period of oscillation of the fans. The three-dimensional equations of motion are integrated to determine the particle trajectories. As first shown by Aref’s work on a two-dimensional map, mixing may be greatly enhanced by unsteadiness. It is found that trajectories can be trapped in a restricted region by surfaces which function similarly to KAM tori in two dimensions. Results are presented for the largest Lyapunov exponent and the correlation dimension as a function of oscillation period. These results may be used to determine the conditions for good mixing.

This content is only available via PDF.
You do not currently have access to this content.