Transient Analysis of Square and Deep Driven Cavity for Different Re Numbers by Lattice Boltzmann Method (LBM)

Abstract

The main objective of the present study was the evolution mechanisms of driven cavity flows for high Re. It was found and proposed the definition of "vorticity channels" which are responsible for the system vorticity input from the walls, either by transport or by diffusion. We studied the vortex dynamic both in deep and square cavities, explaining the mechanism of binding of vortices that occurs repeatedly during the evolution to steady state. For deep cavities a phenomenon that was called "mirror phenomenon" was observed and that it occurs during the formation of the two vortices that appears in steady state. In conjunction with the above, the system circulation was studied for different Re numbers where it was found that for Re 10.000, the system allows vorticity to accumulate three times more than for Re 1.000. We also studied the periodic steady states that arise due to Hopf bifurcation for high Re numbers i.e., grater than 8.000 in the cavity, being the first study to submit a complete cycle of the period that occurs in a deep cavity for Re 8.000.