Rheology via nonequilibrium molecular dynamics

Conference · Fri Oct 01 04:00:00 EDT 1982

OSTI ID:6826253

Hoover, W G

The equilibrium molecular dynamics formulated by Newton, Lagrange, and Hamilton has been modified in order to simulate rheologial molecular flows with fast computers. This modified Nonequilibrium Molecular Dynamics (NEMD) has been applied to fluid and solid deformations, under both homogeneous and shock conditions, as well as to the transport of heat. The irreversible heating associated with dissipation could be controlled by carrying out isothermal NEMD calculations. The new isothermal NEMD equations of motion are consistent with Gauss' 1829 Least-Constraint principle as well as certain microscopic equilibrium and nonequilibrium statistical formulations due to Gibbs and Boltzmann. Application of isothermal NEMD revealed high-frequency and high-strain-rate behavior for simple fluids which resembled the behavior of polymer solutions and melts at lower frequencies and strain rates. For solids NEMD produces plastic flows consistent with experimental observations at much lower strain rates. The new nonequilibrium methods also suggest novel formulations of thermodynamics in nonequilibrium systems and shed light on the failure of the Principle of Material Frame Indifference.

• Research Organization: Lawrence Livermore National Lab., CA (USA)
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 6826253
• Report Number(s): UCRL-88315; CONF-8210114-1; ON: DE83004302
• Country of Publication: United States
• Language: English

Related Subjects

640410 -- Fluid Physics-- General Fluid Dynamics
657006* -- Theoretical Physics-- Statistical Physics & Thermodynamics-- (-1987)
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
COMPUTERIZED SIMULATION
DOCUMENT TYPES
EQUILIBRIUM
FLUID MECHANICS
MECHANICS
MOLECULES
NONLINEAR PROBLEMS
REVIEWS
RHEOLOGY
SIMULATION
THERMODYNAMICS