Simulation of time-dependent flow in cavities with the additive-correction multigrid method .2. Applications

An additive-correction multigrid method for the prediction of two-dimensional unsteady flows, described in a previous article [1], is applied to selected cavity flow problems. The cases considered are the lid-driven cavity problem and the Buoyant flow in differentially heated cavities. Accurate results are obtained for the lid driven cavity, where fine-grid, high-Reynolds-number calculations, indicate that the steady flow bifurcates to a periodic regime for a Reynolds value in the range 7,500-10,000. The results for side-heated rectangular enclosures are presented first for a Prandtl number equal to Zero, and corresponding values of Grashof number of 1.2x10(5) and 1.6x10(5). In addition, a Prandtl number of 0.71 is considered, with values of the Rayleigh number of 1x10(8), 2x10(8), and 2x10(9). The study demonstrates that the additive correction multigrid method is computationally efficient, and is capable of performing accurate simulations of time-dependent, and possibly chaotic, flows in enclosures.