Studies in molecular dynamics of the friction coefficient and the Lorentz gas
Abstract
Various hard sphere molecular dynamics studies are presented. The first describes a modification of Fick's diffusion law, required whenever long time correlations are present. For the Lorentz gas, the nonMarkovan nature of the transport process is shown to correspond to a random walk where, after each step, the particle waits for a time as sampled from a waiting time distribution before making the next move. Second, the mass and size dependence of the friction coefficient as well as its dependence on boundary conditions is discussed. A molecular dynamics method is presented which calculates the infinitemass friction coefficient of finite size hardsphere particles. The applicability of hydrodynamics is considered to describe fluctuations in fluids on the molecular level. It is shown that the fluctuations present in a system of hard spheres, when placed between closely spaced parallel hard walls, lead to an acoustical resonance for those wavelengths which correspond to the spacing, or integer fractions thereof.
 Publication:

Ph.D. Thesis
 Pub Date:
 1979
 Bibcode:
 1979PhDT........19A
 Keywords:

 Lorentz Gas;
 Molecular Diffusion;
 Molecular Interactions;
 Boundaries;
 Boundary Conditions;
 Coefficient Of Friction;
 Diffusion Coefficient;
 Ficks Equation;
 Hydrodynamics;
 Normal Density Functions;
 Resonant Vibration;
 Stokes Law (Fluid Mechanics);
 Atomic and Molecular Physics