PATTERNS IN 3D VERTICALLY OSCILLATED GRANULAR LAYERS - SIMULATION ANDEXPERIMENT

Numerical simulations and laboratory experiments are conducted for thi n layers of particles in a vertically oscillated container as a functi on of the frequency f, amplitude A, and depth H. The same standing wav e patterns (stripes, squares, or hexagons oscillating at f/2 or f/4) a nd wavelengths are obtained in the simulations and experiments for a w ide range of (f,A) and two layer depths. Two model parameters are dete rmined by fits at just two points (f,A,H). Simulation results lead to heuristic arguments for the onset of patterns and the crossover from s quares to stripes.