Zeinab Pouransari - Assistant professor, Department of Mechanical Engineering, Iran University of Science and Technology, Tehran, Iran
Amin Rasam - Assistant professor, Shahid Beheshti university/department of mechanical and energy engineering
Ali Malekan - Student, Department of Mechanical Engineering, K.N. Toosi University of Technology, Tehran, Iran,

Mixing in laminar flows is an essential and important aspect in many industrial systems. Numerical simulation can provide a better understanding of the laminar mixing mechanism. In the present study, a twodimensional lid-driven cavity flow with different timeperiodicforcing protocols of the moving lid is considered. The study focuses on the fundamental symmetrical characteristics of the mixer geometry under chosen mixing protocols to find the poorly mixed spots and the resulting structures. These structures are geometricallythe main keys to determine the mixing properties of the flow. It is observed that the topology of the flow depends on the Strouhal number and varies with the forcing protocol configurations. Furthermore, in the next step of this study, the fluid inertia can induce partialbreakdown of these structures of the non-inertial limit into completely chaotic regions. From the non-linear dynamical viewpoint, this response to inertial perturbations is believed to pave the way for understanding of the chaotic process of mixing.

Mixing, chaotic advection, cavity flow