CONTINUUM-TYPE STABILITY BALLOON IN OSCILLATED GRANULAR LAYERS

The stability of convection rolls in a fluid heated from below is limi ted by secondary instabilities, including the skew-varicose and crossr oll instabilities. We observe a stability boundary defined by these sa me instabilities in stripe patterns in a vertically oscillated granula r layer. Molecular dynamics simulations show that the mechanism of the skew-varicose instability in granular patterns is similar to that in convection. These results suggest that pattern formation in granular m edia can be described by continuum models analogous to those used in f luid systems.