Institute for Mathematical Physics Computer Simulation of Irreversible Expansions via Molecular Dynamics, Smooth Particle Applied Mechanics, Eulerian, and Lagrangian Continuum Mechanics Computer Simulation of Irreversible Expansions via Molecular Dynamics, Smooth Particle Applied Mechanics, Eulerian, and Lagrangian Continuum Mechanics

We simulate the far-from-equilibrium irreversible expansion of a compressed ideal gas in two space dimensions. For this problem the particle trajectories from conventional Smooth Particle Applied Mechanics are isomorphic to those from a corresponding molecular dynamics simulation. The smooth-particle \weight function", used to describe the expanding gas, is identical to the pair potential governing the molecular dynamics simulation. These many-body particle simulations are compared with those using a modiied smooth-particle algorithm invented by Monaghan, as well as with those based on conventional grid-based Eulerian and Lagrangian methods.