Flow Evolution Mechanisms of Lid-Driven Cavities

摘要: The flow in cavities studies the dynamics of motion a viscous fluid confined within cavity which lower wall has horizontal at constant speed. There exist two important reasons whichmotivate study flows. First is use this particular geometry as benchmark to verify formulation and implementation numerical methods second inside become very Reynolds (Re) number increased, i.e. decreasing viscosity. Most studies, concerning cavity, focus their efforts on steady state, but few mechanisms evolution or transients until state achieved (Gustafson, 1991). Own latter aproach it was considered interesting understand associated with reached per se, since for different Re numbers (1,000 10,000) states are ”similar” reach them completely different. In order Lattice Boltzmann Method (LBM) chosen solve dynamic system. LBM created late 90’s derivation Gas Automata (LGA). idea that governs method build simple mesoscale kinetic models replicate macroscopic physics after recovering macro-level (continuum) obeys equations Navier Stokes (NS) equations. motivation using lies computational reason: Is easier simulate through microscopic approach, more general than continuum approach (Texeira, 1998) cost other NS solvers. Also worth mention prime characteristic present themethod itself primitive variables were vorticity-stream function not usual pressure-velocity variables. It intended, by chosing better way because what characterizes movement creates an impulse vorticiy transported diffusion advection. This transport vorticity create vortex responsible its interaction. next sections states, periodic flows feeding going be studied square deep cavities. 17