Abstract

"In this paper we study, using Boltzmann's equation and molecular-dynamic simulations, a one-dimensional column of N inelastic point particles, in the quasielastic limit, under the influence of gravity. The column has no top boundary and it is subjected to a permanent energy injection at a fixed base chosen to behave like a ""hot wall."" The quasielastic condition plus the boundary condition guarantee molecular chaos. The energy injection is of enough intensity to keep the system permanently in a low density state. The system - which would have a homogeneous temperature if it were conservative - shows a temperature gradient because of dissipation. It is shown that, after adimensionalizing, the physical properties in the hydrodynamic limit (N??) depend solely on the product qN, where q is an inelasticity coefficient. Comparison of our molecular-dynamic results with this theoretical picture is excellent. ©1999 The American Physical Society."