13 Matching Results

Search Results

Advanced search parameters have been applied.
in creator/contributor: "Hoover, W. G."  
Results: 1 - 13
open access

Adiabatic Hamiltonian Deformation, Linear Response Theory, and Nonequilibrium Molecular Dynamics

Description: Although Hamiltonians of various kinds have previously been used to derive Green-Kubo relations for the transport coefficients, the particular choice described is uniquely related to thermodynamics. This nonequilibrium Hamiltonian formulation of fluid flow provides pedagogically simple routes to nonequilibrium fluxes and distribution functions, to theoretical understanding of long-time effects, and to new numerical methods for simulating systems far from equilibrium. The same methods are now be… more
Date: May 28, 1980
Creator: Hoover, W. G.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Flow and plasticity via nonequilibrium molecular dynamics

Description: The viscous flow of fluids and the plastic flow of solids, such as metals, are interesting from both the practical and the theoretical points of view. Atomistic molecular dynamics simulations provide a way of visualizing and understanding these flows in a detailed microscopic way. Simulations are necessarily carried out at relatively high rates of strain. For this reason they are ideally suited to the study of nonlinear flow phenomena: normal stresses induced by shear deformation, stress rotati… more
Date: June 11, 1984
Creator: Hoover, W. G.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Fragmentation of Suddenly Heated Liquids in ICF Reactors. Revision 1

Description: Fragmentation of free liquids in Inertial Confinement Fusion reactors could determine the upper bound on reactor pulse rate because increased surface area will enhance the cooling and condensation of coolant ablated by the fusion x rays. Relaxation from the suddenly (neutron) heated state will move a liquid into the negative pressure region under the liquid-vapor P-V dome. The resulting expansion in a diverging geometry will hydrodynamically force the liquid to fragment, with vapor then forming… more
Date: April 17, 1985
Creator: Blink, J. A. & Hoover, W. G.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Chaotic dynamics in dense fluids

Description: We present calculations of the full spectra of Lyapunov exponents for 8- and 32-particle systems with periodic boundary conditions and interacting with the repulsive part of a Lennard-Jones potential both in equilibrium and nonequilibrium steady states. Lyapunov characteristic exponents lambda/sub n/ describe the mean exponential rates of divergence and convergence of neighbouring trajectories in phase-space. They are useful in characterizing the stochastic properties of a dynamical system. A n… more
Date: September 1, 1987
Creator: Posch, H. A. & Hoover, W. G.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Plastic dislocation motion via nonequilibrium molecular and continuum dynamics

Description: The classical two-dimensional close-packed triangular lattice, with nearest-neighbor spring forces, is a convenient standard material for the investigation of dislocation motion and plastic flow. Two kinds of calculations, based on this standard material, are described here: (1) Molecular Dynamics simulations, incorporating adiabatic strains described with the help of Doll's Tensor, and (2) Continuum Dynamics simulations, incorporating periodic boundaries and dislocation interaction through str… more
Date: September 29, 1980
Creator: Hoover, W. G.; Ladd, A. J. C. & Hoover, N. E.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Searching for Auxetics with DYNA3D and ParaDyn

Description: We sought to simulate auxetic behavior by carrying out dynamic analyses of mesoscopic model structures. We began by generating nearly periodic cellular structures. Four-node 'Shell' elements and eight-node 'Brick' elements are the basic building blocks for each cell. The shells and bricks obey standard elastic-plastic continuum mechanics. The dynamical response of the structures was next determined for a three-stage loading process: (1) homogeneous compression; (2) viscous relaxation; (3) uniax… more
Date: September 11, 2004
Creator: Hoover, W. G. & Hoover, C. G.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Computer simulation of nonequilibrium processes

Description: Recent atomistic simulations of irreversible macroscopic hydrodynamic flows are illustrated. An extension of Nose's reversible atomistic mechanics makes it possible to simulate such non-equilibrium systems with completely reversible equations of motion. The new techniques show that macroscopic irreversibility is a natural inevitable consequence of time-reversible Lyapunov-unstable microscopic equations of motion.
Date: January 1, 1987
Creator: Hoover, W. G.; Moran, B.; Holian, B. L.; Posch, H. A. & Bestiale, S.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Smoothed-particle hydrodynamics and nonequilibrium molecular dynamics

Description: Gingold, Lucy, and Monaghan invented a grid-free version of continuum mechanics ``smoothed-particle hydrodynamics,`` in 1977. It is a likely contributor to ``hybrid`` simulations combining atomistic and continuum simulations. We describe applications of this particle-based continuum technique from the closely-related standpoint of nonequilibrium molecular dynamics. We compare chaotic Lyapunov spectra for atomistic solids and fluids with those which characterize a two-dimensional smoothed-partic… more
Date: August 1, 1993
Creator: Hoover, W. G. & Hoover, C. G.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Microscopic and macroscopic dynamics

Description: Atomistic Molecular Dynamics and Lagrangian Continuum Mechanics can be very similarly adapted to massively-parallel computers. Millions of degrees of freedom can be treated. The two complementary approaches, microscopic and macroscopic, are being applied to increasingly realistic flows of fluids and solids. The two approaches can also be combined in a hybrid simulation scheme. Hybrids combine the fundamental constitutive advantage of atoms with the size advantage of the continuum picture.
Date: June 1, 1993
Creator: Hoover, W. G.; Hoover, C. G.; De Groot, A. J. & Pierce, T. G.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Microscopic time-reversibility and macroscopic irreversibility: Still a paradox

Description: Microscopic time reversibility and macroscopic irreversibility are a paradoxical combination. This was first observed by J. Loschmidt in 1876 and was explained, for conservative systems, by L. Boltzmann the following year. Both these features are also present in modern simulations of classic many-body systems in steady nonequilibrium states. We illustrate them here for the simplest possible models, a continuous one-dimensional model of field-driven diffusion, the so-called driven Lorentz gas or… more
Date: September 13, 1995
Creator: Posch, H. A.; Dellago, Ch.; Hoover, W. G. & Kum, O.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Nonequilibrium Molecular Dynamics

Description: The development of nonequilibrium molecular dynamics is described, with emphasis on massively-parallel simulations involving the motion of millions, soon to be billions, of atoms. Corresponding continuum simulations are also discussed. 14 refs., 8 figs.
Date: November 1, 1990
Creator: Hoover, W.G. (California Univ., Davis, CA (USA). Dept. of Applied Science Lawrence Livermore National Lab., CA (USA))
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
Back to Top of Screen