Rise-Time Regimes of a Large Sphere in Vibrated Bulk Solids

We report experiments on the rise time {bold {ital T}} of a single large sphere within a sinusoidally vibrated bed (amplitude {ital a}) of uniform particles (diameter {ital d}). At fixed acceleration, we identify three distinct behavioral regimes both from visual observations and from the typical increase of {ital T} with frequency {ital f}. We observe two convective regimes separated by a critical frequency and, for low {ital a} and high {ital f}, a {open_quotes}nonconvective{close_quotes} regime. In the latter, the bed crystallizes and a size dependent rise is evidenced. We show the relevance of the nondimensional parameter a/d and deduce a scaling law of the form f{proportional_to}d{sup -1/2}. {copyright} {ital 1997} {ital The American Physical Society}